Cardboard bumblebee nestbox

Abstract

The present invention relates to the field of bumblebee handling in particular in relation to bumblebee rearing, storage, transport and at the pollination location. For these purposes the invention according to a first aspect provides a housing, such as a nest box, for bumblebee (Bombus spp.) individuals, including bumblebee workers. Further aspects of the invention relate to the use of the housing for confining bumblebees and a method of pollinating blooming plants comprising providing in the vicinity of the plants a number of bumblebee housings according to the invention.

Description

[0001] CARDBOARD BUMBLEBEE NESTBOX

[0002] Field of the invention

[0003] The present invention relates to the field of bumblebee handling in particular in relation to bumblebee rearing, storage, transport and at the pollination location.

[0004] Background

[0005] Bumblebees are beneficial insects widely used as pollinators in agriculture, including horticulture, vegetable and fruit farming and seed propagation. In view of their important role as pollinators they are mass produced by specialized companies. In general, a typical bumblebee population, depending on the application, shipped for pollination comprises approximately 10-250 adult workers. For many applications the population will also comprise a mature queen (the founder queen) and a multitude of eggs, larvae and pupae. Possibly a number of young queens and / or drones (in a premature life stage and / or in a mature life stage) may also be present. In the current practice, such populations are reared in rearing units by isolating young queens from a population, allow them to mate and hibernate and allowing them to lay eggs in a rearing unit. When workers are present the growing population may be confined in the same or a differing rearing unit formed by a plastic box closed with a plastic lid.

[0006] At full development the bumblebee population may be transferred to a nestbox having a volume similar to or different from the rearing unit and is transported to the agricultural sites where the pollinating activity is required. Transport to such locations may take an additional 1-7 days (occasionally, depending on the distance to the pollination site up to 14 days) and may be by any suitable transport means including road transport, water transport and / or air transport.

[0007] Typically, the development time of a population from the moment of installation of the hibernated queen until shipping the hive for pollination purpose is about 9-12 weeks. The development of the colony continues during transport and the pollination period at the agricultural site. Typically, the development time of a population from shipping the hive until emergence of adult queens and drones is about 1-3 months. In view of the fact that bumblebee workers have excellent gnawing capabilities combined with their ability to sting, securely confining bumblebee populations is an important requirement during rearing, storage and transport. Secure confinement is also of importance at the pollination location for example for relocation of active colonies or during periods when the crop is chemically treated.

[0008] In view of the above, escape of bumblebees from their confining structure should be minimized and preferably must be prevented at all times in order to secure safety of workers involved with the handling of the bumblebee product and / or to maintain quality of the bumblebee product. This puts stringent requirements on the characteristics of the materials used for structures, such as nest boxes or other packaging structures, in which bumblebees are confined during the process of rearing and / or storage and / or transport and / or at the pollination location.

[0009] At present most structures commercially used for confining bumblebees are made of thick-walled plastic to secure bumblebee confinement. It is generally believed within the field that the use of such thick-walled plastic materials is required to securely confine bumblebees, whose stings not only are an inconvenience, but even can cause health risks. Examples of such bumblebee products using thick- walled plastic materials currently marketed are the Natupol Excel products of Koppert (Berkel en Rodenrijs, NL). The production of bumblebee products utilizing such thick-walled plastic materials involves relatively expensive production techniques such as thermoforming or injection molding for forming the plastic parts. In addition, at the end of the life-time, the bumblebee nestbox needs to be disposed as waste. It requires no explanation that it is highly desirable to reduce the amount of plastic in waste streams. Thus, there is a need for confining bumblebee populations while using less or even no plastic materials.

[0010] WO2014182163A1 discloses the use of a laminated cellulose board and a nestbox constructed therefrom for confining Bumblebees. The laminate comprises a cellulose board, covered with a 10-500 pm thick layer of a material comprising a number of polymers, said polymeric material having a tensile strength of at least 25 MPa and a microhardness of at least 80MPa. The invention of WO2014182163A1 is already a significant improvement in the reduction of plastic materials required in bumblebee nestboxes for securely confining bumblebees and is used in the Natupol Booster product of Koppert (Berkel en Rodenrijs, NL). However, the production of the laminate of WO201218163 is not simple, thus the laminate is relatively expensive. In addition, in the Natupol Booster product ventilation openings are incorporated which are covered by a plastic mesh to prevent bumblebee escape. The ventilation meshes still add plastic to the product. In addition, incorporating the meshes in the product is burdensome in production. The present invention is the result of research into alternative ways to securely confine bumblebees using low amounts of plastic while at the same time using simple and cost-effective materials.

[0011] In this research it was surprisingly found that in the absence of light in the confinement chamber of bumblebees, escape behaviour and / or connected gnawing behaviour is not induced and / or sufficient suppressed. This surprising finding does not directly translate into improved methods for confining bumblebees, in view of the general conviction in the art that sufficient gas exchange and sufficient removal of excess (metabolic) heat is required for maintaining populations of bumblebee individuals and / or for the development of the population. The ventilation openings thus considered required in the art will always allow entry of light into the confining chamber. In the research leading to this invention it was also surprisingly found that the level of ventilation thus far considered required is higher than the actual requirement and that bumble individuals can be confined for several days in a chamber enclosed by cellulose board only without the use of ventilation openings.

[0012] Thus, it has now become possible to confine bumblebee individuals with the use of only regular cellulose board, in particular cardboard, without the use of more rigid materials, such as plastic enclosures or polymer-laminated cellulose board. This surprising finding opens new concepts of confining bumblebees and constructing bumblebee nestboxes for confining bumblebees.

[0013] Summary of the invention

[0014] The invention according to a first aspect thus relates to a housing, such as a nest box, for bumblebee (Bombus spp.) individuals, including bumblebee worker adults, comprising: (i) a number of barriers, formed from panels of barrier material preferably selected from cellulose board, such as corrugated cardboard, or solid cardboard;

[0015] (ii) a number of chambers, including a brood chamber suitable to house adult bumblebee individuals, preferably workers, preferably together with larval brood, enclosed by the barrier material, wherein said brood chamber has a volume V, preferably a volume V of between 0,7- 103- 98- 103cm3;

[0016] (iii) a number of passageways for the bumblebee workers between the brood chamber and the exterior of the bumblebee housing, said number of passageways having a closed and an open position, each passageway in the open position having an area (Apw), preferably an area (Apw) of between 0,50-36,0 cm2, more preferably 0,75-16,0 cm2.

[0017] By constructing the bumblebee housing, and in particular the brood chamber where the bumblebee adults reside, in such a way that light is prevented to enter when the passageway is closed, it is sufficient to use normal cardboard, and comparable cellulose board materials, as the confining material. However, according to certain embodiments other materials, in particular other biodegradable materials may also be used.

[0018] A further aspect of the invention relates to the use of a housing according to the invention for confining bumblebees, preferably workers, more preferably workers together with larval brood.

[0019] Yet a further aspect of the invention relates to a method of pollinating blooming plants comprising providing in the vicinity of the plants a number of bumblebee housings according to the invention having an opened bumblebee passageway and allowing bumblebee workers to pollinate the blooming plants. Detailed description of the invention.

[0020] The housing according to the invention is suitable for confining adult bumblebee individuals, such as bumblebee workers. The bumblebees, for which the device is suitable for confinement, may be selected from any species from the genus Bombus such as in particular B. terrestris, more in particular B. terrestris terrestris, B. terrestris audax, B. terrestris dalmatinus, B. terrestris lusitanicus, B. terrestris sassaricus, B. canariensis (or alternatively B. terrestris canariensis). B. impatiens, B. vosnesenskii, B. ignitus, B. diversus, B. occidentalis , B. hypocrita, B. hypocrita ssp. sapporoensis, B. huntii, B. dahlbomii including any sub-species of any of the mentioned species. The bumblebee species in particular is a social species, preferably B. terrestris including any sub-species.

[0021] The number of bumblebee individuals that may be confined in the device may start at a single individual and may range up to 350 or even more. Typically, populations of bumblebees used for pollination or reared for such purposes may comprise 10-250 workers or even more. In view of this, according to certain embodiments the device is suitable for confining over 5 adult individuals, such as about 10-2500, preferably 10- 500, more preferably 40-250 adult individuals, preferable workers. It should be understood that the bumblebee workers may form part of a bumblebee population comprising bumblebee individuals of other classes such as a mature queen (the founder queen), eggs, larvae and / or pupae. Possibly a number of young queens and / or drones (both in a premature life stage and / or in a mature life stage) may also be present.

[0022] The terms “confining”, “confined” and similar terms, within the context of this invention should be construed to mean to keep (maintain) within boundaries, in particular within the boundaries of the nestbox.

[0023] For creating the structure of the nestbox and for confining the bumblebee individuals, the nestbox comprises a number of barriers, preferably barrier panels, formed from sheets of barrier material, preferably selected from cellulose board, such as corrugated cardboard, or solid cardboard. However, according to certain embodiments other suitable materials may also be used. In particular other biodegradable materials. The term “cellulose board” should be construed as referring to any board shaped material consisting essentially of cellulose fibres with optionally a number of added constituents to affect the quality of the board and its fitness for intended end use. For example a number of water-resistant additives may be added, in particular to exterior surfaces to enhance water resistance. The cellulose board preferably is selected as solid paperboard (solid fibre board) or fluted or corrugated paper board (fluted or corrugated fibre board). The use of corrugated (fluted) paperboard is most preferred. According to standards set by the paper industry “paperboard” generally refers to paper material having a product sheet weight (grammage) of over 150 g / m2. According to the invention the cellulose board may have a mass of at least 200 g / m2, preferably 200-3000 g / m2, such as 200-2000 g / m2, more preferably 550-1200 g / m2. According to preferred embodiments of the invention cellulose board comprises > 50%, such as >70% > 80%, > 85%, > 90%, > 95%, of the total weight of solid materials used in the housing, preferably 70%-100%, such as 70%-97%, or 75-90%. The expressed percentage cellulose board is based on the total weight of solid materials used in the housing. The solid materials referred to are the materials used for construction of the housing, thus food sources for the bumblebees should not be taken into consideration for the calculation of this percentage. According to certain preferred embodiments the aim is thus to use cellulose board as the main construction material for a bumble nestbox and to use as little as possible other materials in its construction, in particular as little as possible undegradable plastic.

[0024] The housing may consist of or comprise a structure, such as a structure comprising a number of chambers, suitable for confining bumblebee individuals, in particular workers. The number of chambers includes a brood chamber suitable to accommodate the presence of adult bumblebee individuals, preferably workers, more preferably workers together with larval brood. Thus, the brood chamber is a chamber suitable to house adult bumblebee individuals, preferably workers, more preferably workers together with larval brood. As used in the present description the term “structure” refers to anything composed of parts arranged together in some way. By confining the bumblebees they are shut in and / or kept in the structure and thus prevented from leaving the structure. The device preferably is suitable as a nestbox for a bumblebee population, preferably comprising workers. The skilled person will readily understand the geometric requirements for devices and / or structures, such as nest boxes, suitable for confining bumblebee individuals, preferably workers. The term “nestbox” is to be construed as including rearing units, transport units and hives, most preferably the nestbox is a hive. Within the context of the present description and the appended claims “a number of’ should be construed as meaning “one or more”, whenever this term is used, unless otherwise stated, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 etcetera. The term “a number of’ thus includes a plurality. Within the context of the present description and the appended claims “a plurality” should be construed as meaning two or more, whenever this term is used, unless otherwise stated, such as 2, 3, 4, 5, 6, 7, 8, 9, 10 etcetera.

[0025] According to particular embodiments, the confining brood chamber comprises a number of sections having an angular geometry. Chambers comprising sections having an angular geometry may comprise a number of corners formed by joining barriers having a flat surface or may comprise a number of barriers having a flat surface that changes direction under an angle, in particular a right angle or an oblique angle. Chambers comprising sections having an angular geometry may be formed in structures having an angular geometry, such as box-like structures.

[0026] A flat surface is to be construed as including an “essentially flat” surface. An “essentially flat surface” being a surface that essentially is flat with only non-essential or minor deviations from a perfectly flat surface. Corners, include locations where converging flat surfaces of different barriers meet (under an angle) at an intersection line or where the direction of a flat surface of a barrier changes directions (under an angle). The angle between converging barriers or of the directional change of the flat surface of a barrier in particular may be a right angle (90°), an oblique angle (not 90° or multitude of 90°), such as an acute angle (> 0°, < 90°) or an obtuse angle (>90°, <180°), or is a reflex angle (>180°, <360°). Typically, the angle may be selected from an angle between 10° and 170°, such as 20-160°, 30-150°, 40-130°, 50-120°, 60-120°, 70-120°, 80-110°, or between 190° and 350°, such as 200-340°, 210-330°, 220-320°, 230-310°, 240-300°, 250-290°, 260-280°.

[0027] The brood chamber should be suitable for confining bumblebee individuals, in particular bumblebee adults, most preferably bumblebee workers, but also queens and drones, when present. Thus, the brood chamber should not have any permanent openings (except for the number of passageways discussed below) which would allow passage of bumblebee individuals, in particular workers. The nestbox, and in particular the brood chamber, does comprise a number of passageways, having a closed state and an open state, for (motile) bumblebee individuals such as exits and / or entries to allow entry and / or exit (in the open state) of motile bumblebee individuals when this is required, for example to allow their pollinating activity. Any passageways present in the open position has an area A, preferably an area A of between 0,50-36 cm2, more preferably 0,75-16 cm2. As the passageway is for passage of motile bumblebee individuals, in particular adult workers, the skilled person will understand that the diameter of the passageway should allow the bumblebee individuals to pass. The skilled person will know that the minimal diameter required to allow motile adult bumblebee individuals, in particular workers, to pass will depends on the species and strain of bumblebees that is maintained in the brood chamber. The passage through the passageway preferably should not result in too much loss of collected pollen. Suitable diameters of the number of passageways may range between 0, 8-6,0 cm, preferably 1,0- 4,0 cm, more preferably 1, 0-3,0 cm, such as 1,5-2, 5 cm. It will be understood that this is the minimal diameter, thus the diameter over the shortest axis of a passageway should be considered. It may further be noted that bumblebee populations are able to adjust the diameter of the passageway by decreasing its diameter with wax produced. Thus, the diameter of the initial passageway provided may be changed by the bumblebee population over time.

[0028] In the structure of the nestbox the number of chambers is formed from a number of barriers. In general, a number of, usually a plurality of, barriers will define a chamber by surrounding a void. Any barrier suitable to surround a number of voids, thus forming a number of chambers, and suitable to confine bumblebee individuals, in particular bumblebee workers, may be used. In general walls or other wall-like barriers, including panels, are preferred. As the skilled person will understand, walls and wall-like barriers, such as panels, are barriers having a length and width larger than the thickness. According to embodiments of the invention the length and width are at least half an order of magnitude, and preferably an order of magnitude, larger than the thickness. According to some embodiments numbers may be considered to differ half an order of magnitude, if the result of the division of the larger number divided by the smaller number is > 5. According to certain embodiments numbers may be considered to differ an order of magnitude, if the result of the division of the larger number divided by the smaller number is > 10.

[0029] According to the invention, entry of light into the brood chamber should be prevented, other than via the number of passageways, when in the open state. Due to this, in the open state of the number of passageways, light can only enter via the number of open passageways. Therefore, there will be no entry points for light into the brood chamber enclosed by barrier material at other points.

[0030] Thus, according to preferred embodiments of the invention the barriers enclosing the brood chamber are configured to prevent entry of light into the brood chamber. As will be clear, the light referred to is exterior light from outside the brood chamber, in particular from outside the nestbox, such as sunlight or light from an artificial light source. The skilled person will understand that in order to prevent entry of light a primary requirement for the barrier material is that it should not be translucent, i.e. it should be opaque at least where it encloses the brood chamber. The barriers enclosing the brood chamber preferably may be configured to prevent entry of light into the brood chamber by absence of openings in the barriers, other than the number of passageways, that have a direct connection with the exterior of the nestbox. A direct connection should be understood to mean a connection via a straight line. It should be understood that in the closed state the number of passageways do not have a direct connection with the exterior of the nest box. Barrier panels having a continuous surface facing the brood chamber will not have openings and thus according to a preferred embodiment may be used to prevent entry of light into the brood chamber. Alternatively, when openings are provided in the surface of a first panel of barrier material, a number of parallel adjoining further panels of barrier material can block the openings in the first panel. In addition, entry of light into the brood chamber may be prevented by tight fitting of the barrier panels at interfaces where they meet under an angle, such as in corners. According to a some embodiments the surface of a number of barrier panels facing the brood chamber is a continuous surface, meaning that they are unpunctured or unopened. According to other preferred embodiments, the surface of a number of barrier panels facing the brood chamber is a discontinuous surface having a number of openings (punctures and / or cutouts), wherein the number of openings on the opposing side of the panel (the side away from the brood chamber) are blocked, preferably by the surface of a further barrier panel, such as a barrier panel adjoining with the barrier panel having the discontinuous surface in a double layer. It will be clear that such a blocked opening in a first barrier panel facing the brood chamber by the surface of an adjacent barrier panel (or a similar blocking) cannot be considered a direct connection between the interior of the brood chamber and the exterior of the brood chamber, in particular not a direct connection that allows light to enter into the brood chamber. In addition, preferably the enclosure of the brood chamber by the barrier panels is designed such that the confining barrier panels tightly adjoin. Such tight adjoining of the barrier panels not only aids in secure confinement of the bumblebees, but also prevents light entry into the brood chamber. The use of a layer of a plurality of barrier materials, such as a double layer of barrier material may further aid in preventing light entry into the brood chamber. Entry of light into the brood chamber may further be prevented by forming at least one circumference of the brood chamber from a single barrier panel. This reduces the number of interfaces between different barrier panels. A single, uninterrupted, barrier panel can be bend and / or folded to form a circumference of the brood chamber. For example, a blank of a sheet of barrier material can be designed to be folded into the bumblebee housing and / or an element thereof, such that an uninterrupted part of the blank is folded and / or bend into a circumference of the brood chamber. Other parts of the blank and / or a number of separate blanks may be designed to be folded and / or bend to elements that close the circumference. By using a blank, tight fitting of barrier panels may also be achieved, preferably the number of blanks is designed for this.

[0031] It will be clear that the brood chamber has a volume (V). It will also be clear for the skilled person that the volume (V) of the brood chamber should be sufficient to maintain the bumblebee population. According to preferred embodiments, the brood chamber has a volume of between 0,7 ■ 103- 98- 103cm3, such as 0,8- 103- 1.2 • 103cm3, 6,0- 103- 9,0- 103cm3, 30- 103- 60- 103cm3. Within these volume ranges a range of different population sizes can be maintained. Based on the number of bumblebee individuals in the volume of the brood chamber a population density, expressed in bumblebees / cm3can be defined. The bumblebee population density in the brood chamber according to certain embodiments is at least 0.003 bumblebee adult individuals per cm3, preferably O.OO3-O.188 bumblebee adult individuals per cm3, such as 0.013- 0.039, 0.008-0.042, 0.004-0.011, 0.003-0.014, 0.046-0.109, 0.071-0.236, 0.012-0.055 preferably 0.01-0.10 bumblebee adult individuals per cm3. It should be understood that within the context of the present invention reference to adults is a refence to imagines.

[0032] According to certain preferred embodiments the barrier material enclosing the brood chamber contains a plurality of layers, such as double layer, of adjoining barrier panels, preferably adjoining cellulose board or paperboard sheets, more preferably adjoining fluted paperboard (fluted cardboard) sheets. This increases the structural integrity of the structure. Adjoining sheets in a plurality of layers, such as in a double layer, should be understood to mean sheets that come in proximity in substantially parallel positions, in particular in parallel positions. Adjoining sheets may at least partially touch. At least partially touching means that their surfaces touch at least at a part of their total area. Although it was already surprising that with the use of a single layer of cardboard without ventilation openings a population of adult bumblebee individuals could be effectively confined and maintained, this is the more surprising for a double layer of cardboard sheets or panels.

[0033] It is most preferred that the surfaces of adjoining barrier panels are unconnected and more preferably that their surfaces are spaced 0.1-5.0 mm from each other, such as 0.3- 5.0 mm, 0.5-3.5 or 1.0-2.5 mm. Due to this a thin interstitial space is created between the layers of barrier material where gas can be located and exchanged. The thickness of the interstitial space need not be uniform and can vary between locations along the surfaces of the adjoining barrier panel sheets. To facilitate the spacing in the interstitial space, a number of spacing bodies can be positioned between adjoining sheets of barrier material. The number of spacing bodies preferably have a hight of 0.3-5.0, such as 0.5-

[0034] 3.5 or 1.0-2.5 mm. The spacing bodies can be any body with the indicated hight. Preferably the cross section of the number of spacing body perpendicular to their hight is relatively small, as in this direction they prevent flow of gas in the interstitial space. The dimensions of the interstitial space can also be influenced by local (partial) compression of the barrier material. It will be understood that (partial) compression of one or both of adjoining barrier panels will create more space between the barrier panels. For example by compression of barrier material channels or tunnels can be formed that facilitate gas transport. The terms channel and tunnel are interchangeably used in this description. The channels / tunnels may for example be 1.0-3.0, such as 1.0-

[0035] 2.5 mm high (perpendicular to the plane of the barrier panel) and 4.0-10.0, such as 6.0- 8.0 mm wide. The length of a tunnel may be sufficient to stretch between ventilation openings connecting to the brood chamber and openings connecting to the exterior of the nestbox, such as in the ventilation chamber (discussed below), when present.

[0036] When a plurality of layers, such as a double layer, of adjoining barrier sheets, preferably adjoining cellulose board sheets, more preferably adjoining fluted paperboard is used, it is further preferred that in adjoining barrier sheets a number of ventilation openings are provided in at least one barrier sheet, such as in the inner layer sheet (contacting the brood chamber), and / or in the outer layer sheet (at the exterior of the nestbox) and / or in an intermediate layer (when present). It should be understood that the number of ventilation openings pierce through the barrier panel wherein they are positioned. The presence of ventilation openings in one of the adjoining barrier panel layers and their connection to the interstitial space may improve the gas exchange between the brood chamber with the exterior of the nestbox. When ventilation openings are provided in the inner layer sheet (contacting the brood chamber) they are preferably provided in a higher position of the brood chamber, such that they are According to certain embodiments, material cutout from a barrier sheet to create a ventilation opening is used as a spacing body in the interstitial space. According to certain embodiments channels formed by compression of barrier material direct towards (or away from) ventilation openings connecting to the brood chamber and / or towards (or away from) openings connecting to the exterior of the nestbox. It will be understood that channels directing towards openings may also be considered as directing away from said openings. It is preferred that channels formed towards (or away from) ventilation openings connecting to the brood chamber are not connecting to such ventilation openings but end in the proximity of the ventilation openings, as additional space in the interstitial space at the location of a ventilation opening can facilitate gnawing of bumblebee workers on the barrier material, which could increase risk of escape.

[0037] When ventilation openings are provided in both of the adjoining barrier panels, in order to prevent entry of light into the brood chamber, a ventilation opening in barrier material contacting the brood chamber (located on the inner layer sheet) does not overlap with a ventilation opening in an adjoining barrier panels. Such non-overlapping ventilation openings are still in gas connection via the interstitial space. It should be understood that barrier material contacting the brood chamber is barrier material that can be contacted by adult bumblebee individuals from the interior space of the brood chamber. According to certain embodiments the edges of non-overlapping ventilation openings in adjoining barrier panels are spaced away at least 5 times, such as at least 10 times the thickness of the interstitial space between the adjoining barrier panels. This will be sufficient to prevent light passing two layers of barrier panel. It is preferred to combine the use of ventilation openings in both adjoining sheets of the barrier material with the use of spacer bodies in the interstitial space. This improves gas flow between the ventilation openings and thus improves the gas exchange between the interior of the brood chamber and the exterior of the nestbox.

[0038] According to further preferred embodiments the housing, apart from the brood chamber, comprises a further chamber, the ventilation chamber. The ventilation chamber is enclosed by barrier material and to enhance gas exchange preferably comprises a number of ventilation openings, more preferably a number of open ventilation connections with the exterior of the housing. The brood chamber borders the ventilation chamber and is in gas connection with said ventilation chamber. This gas connection preferably is via gas passages that allow gas exchange between the brood chamber and the ventilation chamber while restricting access of the bumblebee workers from the brood chamber to the ventilation chamber. Gas passages having a maximal width of at most 7.0 mm, such as at most, 6.5, 6.0, 5.5, 5.0, 4.5, 4.0, 3.5, 3.0, 2.5, 2.0, 1.5, 1.0, 0.9, 0.8, 0.7, 0.6, or at most 0.5 mm may be suitable for this. Preferably the gas passages have a maximal width of 0.2 - 3.0 mm, such as 0.2-2.5 mm or 0.2-2.0 mm. According to some embodiments larger openings may be used for gas connection between the brood chamber and the ventilation chamber. Because bumblebee individuals, in particular workers, could pass through such larger openings, a shielding body covering the openings is then required to prevent bumblebee individuals to move into the ventilation chamber. The shielding body may be any body that covers the openings while preventing bumblebees from passing to the ventilation chamber, such as a body comprising bars or a grid. According to certain embodiments the brood plate or stolp bottom frequently used in bumblebee nestboxes can be used as such a covering body.

[0039] The ventilation chamber via its gas connection with the brood chamber increases the total volume of gas that is available for the bumblebees in the brood chamber. With the use of the ventilation chamber the population density in the confining brood chamber can be kept relatively high, as the bumblebees cannot access the ventilation chamber, while the available volume of gas is still relatively high. Thus, the use of the ventilation chamber makes the available breathing volume more independent from the available habitation volume. It has been found that at higher population densities adult bumblebee workers show more initiative to forage and thus to collect pollen. Thus, a smaller habitation volume may increase pollination activity when the number of passageways is opened at the pollination location.

[0040] The gas connections between the brood chamber and the bordering ventilation chamber may be formed at an interface, such as an intersection, of joining, such as converging, barrier material sheets. The skilled person will understand that due to fitting tolerances slits and / or cracks and / or openings may be formed at the interfaces, such as edges and / or corners, of joining parts of barrier material sheets. In particular, in corners formed at joining sheets of barrier material slits and / or cracks and / or openings may be formed. The angles of such corners preferably are between 10° and 150°, such as 60°- 120°, more preferably 80°-100°, most preferably about 90°. About 90° most preferably particular is 90°. When located between the brood chamber and the bordering ventilation chamber, such slits and / or cracks and / or openings can function as gas passages that allow exchange of gas between these chambers.

[0041] In order to further improve gas exchange, the ventilation chamber preferably contains a number of ventilation openings. The ventilation openings may be ventilation openings as described above. Since the bumblebee individuals do not have access to the ventilation chamber, the ventilation openings in the ventilation chamber can be in direct connection with the exterior of the housing. When the barrier material enclosing the ventilation chamber is used in a plurality of adjoining sheets, such as a double layer of barrier panels, similar to what is discussed above, the number of ventilation openings may be provided in at least one barrier panel, such as in the inner layer sheet (contacting the brood chamber), and / or in the outer layer sheet (at the exterior of the nestbox) and / or in an intermediate layer (when present). It should be understood that also for the ventilation chamber, the number of ventilation openings pierce through the barrier material wherein they are positioned. According to certain embodiments, when ventilation openings are provided in both of adjoining barrier panels, a ventilation opening in barrier material contacting the ventilation chamber does not overlap with a ventilation opening in the adjoining barrier panel. According to certain alternative embodiments, when ventilation openings are provided in both of adjoining barrier panels, a ventilation opening in barrier material contacting the ventilation chamber overlaps with a ventilation opening in the adjoining barrier.

[0042] According to some embodiments, in the closed state of the number of passage ways, the gas passages between the brood chamber and the ventilation chamber are the only gas connections between the brood chamber and the exterior of the brood chamber. The gas passages between the brood chamber and the ventilation chamber will have a summed total area consisting of the sum of the area (Agp) of the individual gas passages. In case the barrier material comprises a plurality of barrier panels, a number of ventilation openings can be provided in the barrier panel contacting the brood chamber, which number of ventilation openings are in contact with the interstitial space between barrier panels. The interstitial space should be considered to be a space outside the brood chamber. When the interstitial space is in contact with the exterior of the housing, for example via a number of (non-overlapping) ventilation openings in a barrier panel contacting the exterior of the housing, the number of ventilation openings in the barrier panel contacting the brood chamber will be in gas connection with the exterior of the housing. The number of ventilation openings in the barrier panel contacting the brood chamber, which are in contact with the interstitial space between barrier panels, also have a summed total area consisting of the sum of the area (Av0) of the individual ventilation openings.

[0043] In the open position of the number of passageways, the open passageways will also provide a gas connection between the brood chamber and the exterior of the brood chamber. According to certain embodiments, it is preferred that in the open state of the number of passageways the sum of the areas (Apw) of the number of (one or more) passage ways is > 10%, such as >15%, >20%, >25%, > 30%, >40%, >45%, >50%, >55%, >60%, >65%, >70%, 75%, >80%, > 85%, >90%, >95% of the total area (Agc) of gas connections between the brood chamber and the exterior of the brood chamber. The total area (Agc) of gas connections between the brood chamber and the exterior of the brood chamber is the sum of the total area (EApw) of the number of passageways in the open state plus the total area (EAgp) of the gas passages between the brood chamber and the ventilation chamber plus the total area (EAVO) of the ventilation openings in the brood chamber connected to an interstitial space. Thus Agc= EApw+ EAgp+ EAVO. It will be understood, that depending on the embodiment, in some embodiments the value of EAgpand / or EAVOmay be 0 (zero), in some embodiments in particular EAgpor EAVOmay be 0 (zero). When in the open state of the number of passageways the sum of the areas (Apw) of the number of (one or more) passage ways is > 10% of the total area (Agc) of gas connections between the brood chamber and the exterior of the brood chamber, this percentage may be 60%-95 such as 75%-95%, more preferably 80-95% of the total area (Agc) of gas connections between the brood chamber and the exterior of the brood chamber. According to certain other more preferred embodiments, in the open state of the number of passageways the sum of the areas (Apw) of the number of (one or more) passageways is l%-50% of the total area (Agc) of gas connections between the brood chamber and the exterior of the brood chamber, preferably 2%-45%, such as 2%- 30%, 2%-20%, 2%- 15% or 2%-10%. In such more preferred embodiments, additional ventilation openings have a larger contribution to the total ventilation area besides the number of passageways.

[0044] According to preferred embodiments the bumblebee hosing of the invention is constructed such that the confining brood chamber is assembled from a plurality of elements including a first container element comprising an open receiving end and a second closing element suitable to close the open receiving end of the container element. Such a container element preferably has a base, a number of barrier walls extending from the base and surrounding a void, the brood chamber void, said barrier walls having a proximal end joining the base and a distal end away from the base, wherein the distal ends of the barrier walls form a circumference defining the receiving opening. The closing element can be any element suitable for closing the receiving end of the container element. Preferably the closing element has a base, a number of barrier walls extending from the base and surrounding a space, the closing element receiving space, suitable for at least partially receiving the number of barrier walls of the container element, at least at their circumference. The closing element barrier walls have a proximal end joining the closing element base and a distal end away from the closing element base, wherein the distal ends of the barrier walls form a circumference defining a closing element receiving opening configured to receive the number of barrier walls of the container element at least partially, at least at their circumference. In receiving the number of barrier walls of the container element at their circumference the closing element can be placed at least partially over the container element and the base of the closing element can close the receiving space of the container element. It should be understood that the base and walls of both the container element and the closing element most preferably are barrier panels.

[0045] In these embodiments it is preferred that gas connection is formed in the closure of the receiving end of the container element by the closing element. Similar to the gas connection between the brood chamber and the ventilation chamber, this gas connection between the open end of a container element and a closing element, such as a lid, preferably is via gas passages that allow gas exchange between the brood chamber and the exterior of the brood chamber, preferably the exterior of the housing, while restricting escape of the bumblebee workers from the brood chamber. These gas passages have the same characteristics as the gas passages between the brood chamber and a ventilation chamber. Suitable and preferred ranges for the maximal width of gas passages are already presented above. Such gas connections between an open-ended container element and a closing element, such as a lid, add to the gas exchange between the brood chamber and the exterior of the brood chamber.

[0046] The bumblebee nestbox of the invention can be constructed largely from cellulose board, such as cardboard or paperboard, in particular from corrugated cardboard. This provides a major reduction of use of plastics relative to existing bumblebee nestboxes. For certain elements, such as the stolp-bottom (or brood plate) used as a support for attachment of bumblebee brood, it may remain beneficial to use plastic in view of the required material properties for such elements. When plastic is used in the nestbox of the present invention, it is preferred that this is formed from a biodegradable polymer such as based on polylactic acid (or polylactide) optionally mixed with other components such as selected from polyhydroxyalkanoates and thermoplastic starch. When a plastic stolp-bottom is used the rigidity of the plastic material may be used as a shield to cover a number of ventilation openings from access by bumblebee workers. For example a number of ventilation openings created between the brood chamber and the ventilation chamber may be shielded by the brood plate. A bumblebee housing according to the invention can be efficiently constructed from a number of blanks from barrier material folded to a designed configuration to form the housing. Due to the fact that constructions folded from blanks in general do not create gas tight fits at the interfaces of different panels, gas connections between a brood chamber and a ventilation chamber can be formed by slits and / or cracks and / or openings in the structure folded from the blank. For example, the blanks of figures 1A and IB can be used to form a bumblebee housing according to the invention. These blanks and how they are folded to form a bumblebee housing according to the invention will be discussed with more detail below. The alternative blanks of figures 3A and 3B can also be used to form a bumblebee housing according to the invention.

[0047] The housing of the invention is suitable for confining the bumblebee population for several days, such as at least as up to 3 days, such as at least up to 4, 5, 6, 7 days, preferably for at least up to 7-12 days, such as at least up to 7-21 days while the number of passageways are in a closed state. Confinement of bumblebee individuals in a nestbox of the invention while the number of passageways are in the closed state is relevant for storage and transport in the time between production and arrival at the pollination location where the bumblebees should perform their pollination activities. For such transit confinement with a closed passageway the bumblebee housing should have sufficient gas exchange capacity to support the bumblebee population during the period of confinement. It has been found that standard range cardboard, and more general cellulose board, provides sufficient gas exchange to support a bumblebee population as used for pollination purposes. From experiments conducted, it may be derived that in a bumblebee housing according to the invention, which depends only on gas exchange through the cardboard material, a bumblebee population can be confined for up to 3-7 days. It is reasonable to expect that this can be extended for a few additional days and that a bumblebee population could be maintained up to 8, 9 or 10 days in such a cellulose board nestbox while the number of passageways are in a closed state.

[0048] When a ventilation chamber, having gas connection with the brood chamber via gas passages, as described above, is used, the gas exchange between the brood chamber and the exterior of the brood chamber is improved or at least better secured. In these embodiments bumblebees can also be maintained for at least up to up to 3-7 days, such as up to 8, 9 or 10 days while the number of passageways are in a closed state and even beyond that for at least up to 12 days. Barrier materials that do not breathe (allow gas exchange), such cellulose board does, may then also be used. The skilled person will be able to select suitable alternative barrier materials. For example polymers could be used, preferably a biodegradable polymer.

[0049] When ventilation openings, according to preferred embodiments described above, are provided in a number of barrier panels contacting the brood chamber and / or in the ventilation chamber (when present), the gas exchange between the brood chamber and the exterior of the brood chamber is improved or at least better secured. In these embodiments bumblebees can be also be maintained for at least up to up to 3-7 days, such as up to 8, 9 or 10 days while the number of passageways are in a closed state and even beyond that for at least up to 12 days, such as up to 12 days. Or expressed differently, for at least up to 3 days, such as at least up to 4, 5, 6, 7 days, preferably for at least up to 7-21 days, such as at least up to 7-14 days while the number of passageways are in a closed state. It will be understood that in this situation all provided passageways are in a closed state. When the use of ventilation openings is combined with the use of the ventilation chamber, bumblebees can also be maintained for at least up to up to 3-7 days, such as up to 8, 9 or 10 days while the number of passageways are in a closed state and even beyond that for at least up to 12, 15 or 21 days. Barrier materials that do not breathe (allow gas exchange), such as cellulose board does, may then also be used. The skilled person will be able to select suitable alternative barrier materials. For example polymers could be used, preferably a biodegradable polymer.

[0050] When after the transit period the nestbox arrives at the pollination location where the bumblebees should perform their pollination activities, a number of passageways will be converted to the open state such that bumblebee individuals can exit and reenter the nestbox. The open state of a passageway also allows gas exchange between the brood chamber and the exterior of the brood chamber, not only directly by providing an additional gas connection between the brood chamber and the exterior of the brood chamber, but for some embodiments also indirectly by providing a pressure release which may improve gas exchange via other ventilation openings, when present for example in the brood chamber and / or the ventilation chamber. Furthermore, when a passageway s in the open state bumblebee workers may leave the nestbox, which will reduce the bumblebee density and production of metabolic gas and heat in the brood chamber. Thus, when a number of passageways is in the open state, gas exchange between the brood chamber and the exterior of the brood chamber is far less of a critical factor and bumblebees may be kept (housed) during extensive periods in the housing of the invention such as for at least up to 14 days, such as at least up to 21, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75 days and preferably up to90 days. It should be understood that also when a number of passageways is opened and motile bumblebee individuals can freely leave the brood chamber, bumblebee individuals inside the housing may still be considered confined in the housing and in particular the brood chamber, since they can only exit the housing via the designated passageway and are limited (confined) by not being able to exit the bumblebee housing in another way.

[0051] When confined for a prolonged time while the number of passageways is in the closed state, sufficient and adequate food should be provided to the confined bumblebee individuals. It is within the ambit of the skilled person to select adequate food sources and what sufficient amounts are for a specific confinement period. In general bumblebee populations require pollen as a protein source and sugars as an energy source. Pollen containing compositions, such as compositions comprising a mixture of pollen and carbohydrates, in particular sugars can thus be used. Optionally, depending on the sugar content of the pollen containing composition, a sugar source can be added separately, such as in the form of a sugar solution, sugar fondant or crystal sugar. In the current Natupol® products of Koppert (Berkel en Rodenrijs, NL), a pollen / sugar mixture is provided together with a sugar solution. This combination of food sources is adequate to maintain a bumblebee population for a prolonged period up to 21 days, or even longer when provided in an adequate amount. The use of a sugar source with a low water content (and thus high solid content), such as sugar fondant or crystal sugar, has benefits in reducing the water content in the excrements of the bumblebees, which provides a better interior environment. Reduction of water content of bumblebee excrements may also result in better maintained quality of cellulose board materials, when these are used. Thus, when a number of carbohydrate food sources is provided to bumblebee individuals, according to certain embodiments preferably any provided carbohydrate food source has a solid content of 70%-99% (w / w) based on the total mass of the food source composition, such as 75%-95%, preferably 80%-95%, such as 85%- 93%, such as for example sugar fondant (sugar dough). Most preferably, the carbohydrate is the main component of the solids, in that it represents >50% (ww) of the solids, such as 75%-100%, preferably 80%-99%. Food sources in (semi)solid form, such as fondant or sugar dough, can be provided directly in the brood chamber, or in a container with an access for the bumblebee individuals, in particular the workers. Sugar fondant (sugar dough) compositions for feeding bees are known in the art, such as Ambrosian dough and comparable compositions. A suitable sugar fondant composition may be based on sucrose and glucose syrup with optional addition of further (higher) sugars and may have a solid content of 83%-91 % (w / w) based on the total mass of the composition.

[0052] When the food source has a large volume, for example up to about 1.9 litre of sugar water can be used, it may be convenient to place this outside the brood chamber. In addition, sugar water is generally presented in a polymer bag, which is under risk of leaking due to gnawing of bumblebees. Thus, when the bumblebee housing comprises a ventilation chamber as discussed above, a container comprising a food source, such as an aqueous sugar solution, for the bumblebee workers is placed in the ventilation chamber and access to the food source is provided in the brood chamber.

[0053] It should be understood that the durability of the selected barrier material, such as cellulose board, should be such that, depending on the environmental conditions where the housing is placed, the bumblebees may be confined for the desired time. In indoor environments, such as encountered during storage and transport, standard cellulose board materials, such as cardboard, corrugated cardboard, are suitable. The same is true for greenhouse conditions, in particular when measures are taken to protect the bumblebee housing from direct water contact. But also for harsher outdoor conditions, as may be encountered in outdoor crops, such as in orchards or sunflower fields, standard cellulose board materials, such as cardboard, corrugated cardboard, are still suitable, in particular when measures are taken to protect the bumblebee housing from direct water contact. Protection from direct water contact may include the use of a shielding cover, covering at least the top side of the bumblebee housing. For this a plate of a water-resistant material having an area larger than the area of the top part of the bumblebee housing may be used. Alternatively, one or more bumblebee housings may be placed inside the mantle space of a horizontally positioned cylinder of a suitable diameter and having open ends. The cylinder mantle of water-resistant material may thus shield the bumblebee housing against water from above and the sides, in particular when the length of the cylinder is long enough to (at least partially) prevent falling water to reach the bumblebee housing via the open ends of the cylinder. In addition, the bumblebee housing may be positioned at an elevation to prevent water contact at its bottom side. For this for example legs may be connected to and / or form part of the bumblebee housing.

[0054] It is further envisaged that the barrier material, such as cellulose board, may be treated to improve its water resistance e.g. by applying a water-resistant layer, in particular to surfaces facing the exterior of the bumblebee housing. The use of materials applied to cellulose board to improve water resistance is known. For example, it is known that films of water-resistant materials can be applied to cellulose board surfaces by lamination or coating, such as spray coating. An inert biodegradable translucent film can for example be created from a blended waterborne acrylic lattice, when coated and dried onto cellulose board, such as cardboard, in particular corrugated cardboard.

[0055] A laminate of cellulose board with a polymeric material, as disclosed in WO2014182163A1, would also have an improved water resistance, in particular when the polymeric material would face the exterior sides of the bumblebee housing. Such a laminate is suitable for use as a construction material for a device, such as a nestbox, for confining bumblebee workers and comprises a cellulose board, preferably solid paperboard, covered with a 10-500 pm thick layer, preferably as an outer surface covering layer, of a material comprising a number of polymers, said polymeric material having a tensile strength of at least 25 MPa and an indentation microhardness of at least 80MPa, wherein in said use a polymeric material side of the laminate preferably is faced to spaces in the device where bumblebee workers may be present. Although less preferred for the present invention, according to certain embodiments, the use of such a laminate disclosed in WO2014182163A1 is thus included in the present invention. When such a laminate is used however for the present invention it will not be used in combination with ventilation openings in the brood chamber having direct connection with the exterior of the brood chamber. In addition, it is most preferred that such a laminate is used as an outer layer on a surface facing the exterior of the bumblebee housing. When coatings and / or other layers that negatively influence gas exchange through the cellulose board barrier sheets are applied to the surface of a cellulose board barrier sheets, including a laminate as disclosed in WO2014182163A1, it is preferred that ventilation via other means is provided. For example, by using a ventilation chamber as discussed above, in particular a ventilation chamber having ventilation openings in open connection with the exterior of the bumblebee housing. Preferably such as ventilation chamber is used together with ventilation openings in the brood chamber connected to an interstitial space between two layers of barrier material, wherein the interstitial space preferably is connected with the ventilation openings in the ventilation chamber. Alternatively, or in addition, ventilation can be increased by using an open-ended container and a closing means, such as a lid, for the open ended container having gas passages between the joining parts of the open ended container and the closing means, as described above.

[0056] According to some embodiments, it is preferred that when a cellulose board is selected as barrier material of the bumblebee housing, it does not comprise a laminate as disclosed in WO2014182163A. Thus, according to some embodiments barrier material contacting the brood chamber does not comprise a cellulose board laminated with a polymeric material, in particular not a laminate comprising a polymeric material selected from polyamide (PA), polystyrene (PS), polyethylene terephthalate (PET), polypropylene (PP), polyvinylchloride (PVC), polylactic acid (PLA) or polyhydroxyalkanoate (PHA), in particular poly-3-hydroxy butyrate-covalerate copolymer (PHBV).

[0057] According to certain other preferred embodiments, the surface of barrier material, in particular barrier material enclosing the brood chamber, has an indentation microhardness of less than 60 MPa, such as < 50MPa, < 40 MPa. Indentation hardness is a material property well known in the art and refers to the resistance of the material to local surface deformation against indentation. It may be measured in tests employing a micro range (9.807*1 O’3to < 9.807 N) or macro range (>9.807 to < 1176.80 N) test force. The indentation hardness determined for the barrier material is measured using a micro range test force and thus may be referred to as indentation microhardness or microhardness. According to a preferred embodiment microhardness is measured according to ASTM-E384 (Standard Test Method for Knoop and Vickers Hardness of Materials), more preferably ASTM-E384-l lel, using a Vickers indenter. Microhardness values for commercially relevant polymers may also be derived from Balta Calleja & Fakirov (2000) or from other sources readily available to the skilled person.

[0058] According to certain other preferred embodiments, the surface of barrier material, in particular barrier material enclosing the brood chamber, has a tensile strength of less than 20 MPa, such as <15 MPa or <10 MPa. Tensile strength is a material property well known in the art and refers to the maximum stress that a material can withstand while being stretched or pulled before failing or breaking. Alternative terms used are Ultimate tensile strength or ultimate strength. According to a preferred embodiment the tensile strength is measured according to ASTM D882 (standard Test Method for Tensile Properties of Thin Plastic Sheeting), more preferably ASTM D882-12. Tensile strength values for commercially relevant polymers may also be derived from Callister (2003), Osborne et al (1992), the Modem Plastics Encyclopedia '96, (McGraw-Hill Companies) or from other sources readily available to the skilled person.

[0059] According to certain preferred embodiments, the surface of barrier material, in particular barrier material enclosing the brood chamber, has a tensile strength of less than 20 MPa, such as such as <15 MPa or <10 MPa, and an indentation microhardness of less than 60 MPa, such as < 50MPa, < 40 MPa.

[0060] As is clear from the above, the bumblebee housing of the invention is for confining bumblebees. The use of the bumblebee housing of the invention for confining bumblebees is therefore a specific aspect of the claimed invention. In this aspect of the invention, the bumblebee housing can be used in all embodiments disclosed above.

[0061] A further aspect of the invention relates to a method of pollinating blooming plants comprising providing in the vicinity of the plants a number of bumblebee housings according to the invention having an opened bumblebee passage and allowing bumblebee workers to pollinate the blooming plants. In this aspect of the invention, the bumblebee housing can also be used in all embodiments disclosed above.

[0062] Details of the invention will now be discussed with reference to the figures and experiments, which relate to non-limiting exemplary embodiments of the invention. Figure 1 discloses two blanks according to an embodiment of the invention. A first blank (1), shown in figure 1A, that can be folded to a container having an open end, and a second blank (2), shown in figure IB, that can be folded to a lid serving as a closing means, for closing the open end of the container. In the presentation of blanks of figure 1, continuous lines represent cut edges, short-dashed lines represent continuous cuts, lines of long and short dashes combined represent folds relieved by cuts, lines formed by long dashes and 3 dots (the dots may appear as a space) represent bending lines. Some key dimensions, as indicated by the arrows, are provided in mm. Other dimensions are derivable.

[0063] The first blank (1) has a first row of connected panels Al, B l, Cl, DI, that form the outer circumference of the brood chamber and the ventilation chamber. For connecting panel Al to panel DI, panel Al comprises a flap Al’ that is fixed, e.g. by gluing, to the surface of panel DI. It should be understood that in the view of figure 1A the back side of Al’ (the invisible side) is fixed to the surface of DI that is visible. Panels Al, Bl, Cl, DI are connected to panels AO, BO, CO, DO respectively that fold to the bottom part of the bumblebee housing. Panels AO and CO have flaps AO’ and CO’. To improve the closing of the bottom of the nestbox, flaps AO’ and CO’ may be fixed to respectively panels BO and CO e.g. by glueing. It should be understood that in the view of figure 1A the back sides of AO’ and CO’ (the invisible sides) can be fixed to the front sides of BO and DO’ (the visible sides).

[0064] In general panels AO, BO, CO, DO form the bottom part of the bumblebee housing, while panels Al, B l, Cl, DI form exterior side barriers of the brood chamber and ventilation chamber, and panels A2, B2, C2, D2 form interior side barriers of the brood chamber and ventilation chamber. Panels A3, B3, D3, form a triple layered separation floor dividing a separate brood chamber and ventilation chamber, wherein flaps A3’, B3” and D3” function as spacers to create stability to the separation floor.

[0065] The folding of the first blank (1) to the open-ended container is schematically presented in the sequence of figures 2A-2K. In the schematical presentation of figures 2A-2K not all details of the first blank (1) are shown. It is considered that the folding of the first blank (1) to the open-ended container shown in figures 2A-K is self-explanatory, in view of the description above.

[0066] The second blank (2) is foldable to a lid configured to close the open-ended container folded from the first blank (1). The second blank (2) comprises a rectangular panel EO that forms the exterior base of the lid. Panel EO is connected with panels El and E2 on one end and E-l (E minus 1) and E-2 on an opposing end. On its other two sides panel EO is connected with panels FL and FR which each are connected to panels FL-1 and FL1 and respectively FR-1 and FR1. Panel FR is connected to panel G which serves as a liker to connect further to panel HO. Panel HO connects to panels Hl and panel H-l.

[0067] In general, in the folding of the second blank (2) panel EO forms the exterior base of the lid while panels FR, FL, El, and E2 are bend in the same direction to form ridges protruding from the base plate EO. Panels E2 and E-2 are bend to overlay panels El and E2 respectively to form a double layer for extra rigidity, in particular in cooperation with panels FR1, FL1, FR1 and FR-1, which are bend to fall between the double layers of the E1 / E2 and E-l / E-2 pairs. Panel HO is folded to overlay EO while Hl and Hl are folded as spacers in between the EO / HO panels.

[0068] The folding of the second blank (2) to the lid for the open-ended container folded from the first blank (1) is schematically presented in the sequence of figures 2L-2O. In the schematical presentation of figures 2L-2O not all details of the second blank (2) are shown. It is considered that the folding of the second blank (2) to the lid for the open- ended container shown in figure 2L-2O is self-explanatory, in view of the description above.

[0069] Together, the open-ended container and the lid can be assembled to an embodiment of a bumblebee housing of the invention as is shown in figures 2P and 2Q. Cuts (10) in panels E2 and E-2 of blank (2) can cooperate with cutouts (16) in panels Al and Cl of blank (1) to secure the lid to the open-ended container. For this the material cut from incisions (10) can be folded back and into the cutouts (16) when the lid is placed on the container for closure. For securing the lid to the open-ended container, the lid alternatively or in addition may also be at least partially fixed to the open-ended container. This may for example be achieved by at least partially fixing one or more of panels FL, G, E2 and / or E-2 to the upper parts of panels B 1, DI, Al and / or Cl respectively. For example, by using glue. When fixing means are used, it is preferred that gas connections remain between the lid and the open-ended container, e.g. by using discontinuous application of glue. Closure by the lid can further be improved by enlarging a number of the side panels (FL, FR, G, El, E2, E-l, E-2).

[0070] Returning to figure 1, some additional features of the disclosed embodiment will be further discussed.

[0071] To allow the bumblebees to exit and reenter, the housing comprises a passageway which in the embodiment of the blank (1) is configured of an opening (3 a) in panel C2 and a peel-open hatch (3b) cut in panel Cl which in the folded configuration is aligned with the opening (3a). The opening (3a) suitably can have a diameter of 0,50-36,0 cm2more preferably 0,75-16,0 cm2. In the embodiment of the blank of figure 1A the diameter of the passageway is 15 mm. As panels Cl and C2 closely adjoin in the folded configuration, the material of the peel-open hatch (3b) covers the opening (3 a) and keeps the passageway in the closed state, by blocking the opening (3a). On arrival of the bumblebee housing on the location where the bumblebees should perform their pollinating activities, the material of the peel-open hatch (3b) can be peeled away to bring the passageway in the open state by unblocking the opening (3a). When the cut is made such that the hatch remains connected to panel C2 from which it is cut, the hatch may be returned to the closed position, when desired, to restore the closed state of the passageway and when necessary can be secured in the closed state with fixing means, such as (adhesive) tape.

[0072] According to certain embodiments the side panels of the lid folded from the second blank (2) are enlarged to the extent that they overlap with the position of the exit opening (3a) in panel C2. In these embodiments aligned openings can be provided in panels Cl and El or E-L The peel-open hatch (3b) can then be provided in panel E2 or E-2, depending on where the other aligned opening is positioned.

[0073] The passageway, in the embodiment of figure 1 formed by the opening (3a) in panel C2 and the peel-open hatch (3b) cut in panel Cl, in the open state not only allows passage of the bumblebees, but also allows gas exchange between the brood chamber and the exterior of the brood chamber. In the closed state of the passageway gas exchange between the brood chamber and the exterior of the brood chamber may proceed via different ways depending on the embodiment of the bumblebee housing of the invention.

[0074] First, gas exchange may occur through the cellulose board material. In the research of the present invention it has been found that standard range cellulose board, in particular corrugated cardboard allows for sufficient gas exchange to support a bumble bee population for the time periods that in general occur between closure of the housing at the end of production and the time when the passageway is opened at the pollution location (in general 3-10 days).

[0075] When an open-ended container, such as folded from the blank (1) of figure 1A is used in combination with a lid, such as folded from the blank (2) of figure IB, gas exchange may additionally proceed via the gas connections that remain between the open-ended container and the lid.

[0076] The embodiment of the open-ended container shown in figure 1A and figures 2, further comprises a ventilation chamber adjacent to the brood chamber. In the folded configuration of the panels (B3, D3, A3) separating the brood chamber from the ventilation chamber and their interface with the panels (A2, B2, C2, D2) forming the walls of the brood chamber, gas connections are present that allow gas exchange between the brood chamber and the ventilation chamber. Thus, the ventilation chamber increase the breathing volume for the bumblebee population, when present in the brood chamber.

[0077] It is further visible that panels B 1 and DI comprise ventilation openings (4). These ventilation openings (4) in the folded configuration of the first blank (1) are located in the ventilation chamber and have an open connection with the exterior of the bumblebee housing. Thus, they increase gas exchange between the exterior of the bumblebee housing and the ventilation chamber. Because the ventilation chamber is in gas connection with the brood chamber via the gas connections formed in the folded configuration between the various panels, these ventilation openings (4) improve the gas exchange in the brood chamber. When a multilayer of barrier panels is used, gas exchange may further be enhanced by incorporating ventilation openings in a barrier panel contacting the brood chamber. In the embodiment of figure 1, such ventilation openings (5, 6) are provided in panels B2, D2 of the blank (1) for folding the open-ended container and panel HO of the blank (2) for folding the lid. The adjacent barrier panels B 1, DI and EO respectively shield the ventilation openings (5, 6) and thus prevent entry of light into the brood chamber via these ventilation openings (5, 6). In the interstitial space between the double layer of barrier panels B1 / B2, D1 / D2 and EO / HO gas flow and thereby gas exchange is possible. For ventilation openings (5) in panels Bl / Dl the interstitial space between panels B1 / B2 and D1D2 is in gas connection with the ventilation chamber further comprising ventilation openings (4). For ventilation openings (6) the interstitial space between panels HO and EO is in connection with openings in panel EO that connect to the exterior of the bumblebee housing. The opening of the interstitial space between panels HO and EO is facilitated by positioning of panels Hl and H-l in between panels EO and HO. The cutouts (9), two in each of the panels Hl and H-l, help to create additional open space in connection with the interstitial space.

[0078] The whole of ventilation openings and gas connections in the bumblebee housing that can be assembled from the folded blanks (1) and (2) of figure 1, provides more than sufficient gas exchange between the brood chamber and the exterior of the brood chamber to confine bumblebees in the brood chamber for prolonged periods of time while passage to outside the brood chamber is restricted. As is shown in the experiments below, this is even possible when certain ventilation functionalities have been removed and / or blocked, showing that even with a lower degree of ventilation, bumblebees can be maintained in a housing using cellulose board barrier material.

[0079] Attention may further be drawn to a number of additional elements that add to the functionality of the folded first blank (1) in a bumblebee housing, in particular a nestbox.

[0080] In order to provide a food source during prolonged confinement of a bumblebee population, a container containing an aqueous sugar solution may be provided in the bumblebee housing, as is generally done. According to embodiments of the invention a standard sugar water container, for example as used in Koppert’s Natupol Excel products, may be provided in the ventilation chamber. Cutouts I la, 11b, 11c in respectively panels B3, D3 and A3 allow the feeding wick device (connected to the sugar water container positioned in the ventilation chamber to reach into the brood chamber. To make this possible, in the folded configuration of the blank (1), the holes of cutouts I la, 11b, 11c are aligned.

[0081] Cutouts 12 (4 in total), 13, 14, in panel A3 and 15 in panel A2 support click-fastening of a stolp-bottom (or brood plate) containing bumblebee, allowing transfer of a bumblebee population from a different rearing unit into the bumblebee housing of the invention. The brood plate without brood is shown in figures 3C-3D. Such a brood plate is already used in the Natupol products of Koppert, such as Natupol Excel. Elements on the brood plate interconnecting with cutouts 12, 13, 14, 15 of the blank (1) of figure 1A are labelled 12*, 13*, 14* and 15* respectively. In particular, the four elements 12* are protruding legs that grab into the four cutouts 12 in panel A3. Element 13* comprises an L-shaped plate element that grabs through cutout 13 and under panel A3. Element 13* works together with retaining ridges 18, which grab on top of panel A3. Element 14* is a rectangular protrusion that in the fastened position sits in cutout 14 and provides stability against movement in the plane of panel A3. Element 15* similar to element 13* comprises an L-shaped plate element. It grabs through cutout 15 and under panel A2. Figure 3E and 3F show a picture of brood plate installed in an embodiment of the housing of the invention, while figure 3B shows a picture of the interior the open- ended container of a bumblebee housing before installing the brood plate and figure 3A a picture of the exterior of a bumblebee housing with the covering lid.

[0082] A cellulose board nestbox according to certain embodiments of the invention may thus be obtained using blanks as shown in figure 1. The blank of figure 1A can be folded to an open box, as shown in figures 2A-2K, while the blank of figure IB, can be folded, as shown in figures 2L-2O to a lid fitting the open box. Together the open box and the fitting lid can be combined to a closed nest box as shown in figure 2P, 2Q and figure 3.

[0083] Figures 4 A and 4B, show alternatives to the blank of figure 1A and IB respectively. In order not to overpopulate the figure with reference numerals, some elements of the blanks of figures 4 A similar to the elements of figures 1A have not been provide with reference numerals. The similarity between the blanks and their elements, in particular as indicated with reference numerals 3a, 3b, 4-10, l la-l lc, 12-18, for the blanks of figure 1A and B will be clear for the skilled person. The blanks of figure 4 A and 4B can be folded to the open container and the lid of the nestbox in a similar way as presented in figures 2A-2Q.

[0084] The blank of figure 4A amongst others differs from the blank of figure 1A in the dimensions and shapes of panels AO (and AO’), BO, CO (and CO’) and DO that interact to form the bottom of the nestbox. In addition, the number and position of the ventilation openings (5) in panels B2 and D2 (facing the brood chamber) and of the ventilation openings (4) in panels B 1 and DI (facing the exterior of the nestbox) differs. Furthermore, flap A3’ comprises a secondary flap A3’*, which in the folding of the blank interacts with flap A3” to provide an improved closure of the nestbox interior from risks of bumblebee escapes. Furthermore, panel B3 differs in shape and comprises a second flap B3” functioning as an additional support for panel B3 in the folded state of the blank. Panel A3 of the blank of figure 4A comprises cross-shaped (+) incisions (19). These incisions (19) can be widened mechanically by applying pressure. Thus, additional ventilation surface in connection with the brood chamber is created. The position of the incisions (19) is at the location where the brood plate (see figure 3) covers panel A3. Thus, the ventilation incisions (19) are shielded by the brood plate. Panels D3 (facing the ventilation chamber) and panel B3 (in the folded state intermediate to panels A3 and D3) comprise openings (21) and (20), respectively. These openings (20) and (21) increase the gas exchange between the ventilation chamber and the brood chamber via incisions 19, but also via the interstitial spaces formed between panels A3, B3, D3 and the gas passages present in the folded configuration of the blank between amongst others panel A3 and B2, C2, D2. In the blank of figure 4A, the closing flap (3b) covering the passageway opening (3a) has an alternative positioning. The alternative blank of figure 4B differs from the one of figure IB in the addition of the flap FL’ , with this addition a double layer of cardboard is provided along the circumference of the lid.

[0085] Figure 12 shows a table presenting combinations of features of various embodiments envisaged within the present invention. In this table a number of variations of features relating to the bumblebee housing in general are labelled N1-N7, a number of variations of features relating to the configuration of the brood chamber are labelled B 1-B4, a number of variations of features relating to the configuration of the ventilation chamber are labelled V1-V3, a number of variations of features relating to the bumblebee density are labelled DI, D2 and a number of variations of features relating to the food source provided are labelled Fl, F2. Combinations of the envisaged in the invention are labelled with a corresponding combination of the labels. Thus, N1B 1 is the combination of variations N 1 and B 1. It will be clear that multiple combinations of feature variations are possible and envisaged by the present invention. For example, the combination B3N3467 is the combination of feature variation Bl with feature variations N3, and N4, and N6 and N7. Preferred combinations of feature variations are shown with bold font, more preferred combinations of feature variations are shown with bold and underlined font.

[0086] EXPERIMENTS

[0087] Prototype phase

[0088] The development towards the bumblebee housing of the invention included several tests and modifications in the initial experimental phases. Early tests focused on evaluating the ability of standard range cellulose board, in particular currogated cardboard, to prevent unintended bumblebee escapes from the brood chamber. Escapes of the bumblebees from the broodchamber during (transit) strorage could create risks for workers handling the products. In addition, when a thin walled plastic container is used for storage of a sugar solution, as is often the case, at any stage escape of the bumblebees into the chamber, where the sugar solution container is stored, is a risk, as bumblebees with their mandibles can and do pierce through the container wall leading to sugar solution leakage. Damage to the sugar water container could significantly compromise the product, as the sugar feeder during storage conditions is essential for bumblebee population maintanance and / or development. In addition, access liquids would impair the integrity of cellulose board materials. Furthermore, spillage of the sugar solution promotes microbial growth.

[0089] During the early discovery phase it was observed that bumblebee escape behavior was initiated at points where light entered the brood chamber. This observation lead to the development of a bumblebee housing folded and assembled from blanks similar to those of figures 1A and IB. Such bumblebee housings were observed to confine bumblebee populations during prolonged periods (beyond 13 days) under extended light exposure (light:dark 8h:16h) while the passage way was in the closed state. Once the suitability of these bumblebee housings to confine bumblebee populations was established, further investigations into the ventilation mechanisms of this housing were conducted as described below.

[0090] Treatments T1-T5

[0091] The bumblebee nestbox obtainable with cardboard blanks of figures 1A and IB is a preferred embodiment of a nestbox using a double layer of sheets of barrier materials and comprising non-overlapping ventilation openings in the barrier material contacting the brood chamber and further comprising a ventilation chamber having open ventilation connections. Using this preferred nestbox, the earlier surprising finding of the invention that bumblebees can be maintained in a cardboard enclosure without ventilation openings that would allow light entry, and that regular types of cardboard thus could already provide sufficient gas exchange for a confined bumblebee population, is experimentally reconfirmed. In addition, the effects of introducing nonoverlapping ventilation openings in the brood chamber and open ventilation openings in the ventilation chamber was investigated. For this, bumblebee populations of similar composition were placed in nestboxes folded from cardboard blanks of figures 1A and IB (see figure 2) in an unmodified form and with 3 differently modified treatments. The carboard used (3VLB26HH) was characterized by KL170 / RF100 / KL275 (grams / sqm), ECTmin=7. The volume of the brood chamber for these nestboxes is about 8,172 cm3, while the volume of the ventilation chamber is about 3,023 cm3. For comparison, data from a bumblebee population confined in a nestbox as used in the commercially available Natupol™ Excel product (Koppert, Nove Zamky, Slovakia) is also presented. The bumblebee populations in all treatments were queenright colonies of Bombus terrestris (subspecies ter rest ri ), selected from Koppert’ s Natupol Excel production (Koppert, Nove Zamky, Slovakia). These colonies at the start of the incubations contained a founder queen, about 120 adult workers and a low number of adult males (0-5), about 130 and 320 Pupae / cocoons and larvae respectively and between 15-35 egg cups. Thus, the adult population density at the start of the treatments was about 0.015 adult individuals per cm3.The different treatments were the following:

[0092] Treatment 1 - Unmodified form of the nest box obtained with cardboard blanks of figures 1A and IB (as shown in figure 3 and described in the text relating to figure 1 and 2. In the ventilation chamber a bag with sugar water (volume about 1.9-2.0 liter) was positioned).

[0093] Treatment 2 - The nestbox of treatment 1 modified by gastight closure of the ventilation openings in the lid and in the ventilation chamber, as schematically shown in figure 5 A.

[0094] Treatment 3 - The nestbox of treatment 1 modified by gastight closure of the total lid area (together with the interface of the lid and the box body) and the bottom part of the box body, as schematically shown in figure 5B. The folding pattern in the bottom of the open-ended container thus was also closed gastight.

[0095] Treatment 4 - The nestbox of treatment 1 fully enclosed in gastight material as schematically shown in figure 5C. The volume of gas enclosed by the gas tight material outside the nestbox was minimized. Thus, the gas volume available to the bumblebee population in this treatment corresponded to the gas volume in the brood chamber (about 8.17 liter) and the remaining volume in the ventilation chamber (about 1.0-1.1 liter).

[0096] Treatment 5 - For comparison, a bumblebee population confined in a nestbox as used in the commercially available Natupol™ Excel product (Koppert™, Nove Zamky, Slovakia). The interior of this nestbox is shown in figure 5D. The volume of the brood chamber was about 26.4 x 24.0x13.0 cm = about 8,236 cm3.

[0097] Gastight closure of the different parts of the nestboxes in the different treatments was accomplished with the use of polymer sheet material (Polyethylene) used for vacuum storage of clothes, a silicone melt gun and transparent tape.

[0098] The nestboxes of the different treatments during the test were maintained at a temperature range of 21-24°C, relative humidity of 47-55% and a CO2 concentration of around 400ppm. Lighting in the room corresponded with typical storage and transport conditions, i.e. dark periods and intermittent exposure to light. The colonies in all tests were provided with sufficient pollen presented in 15 gram cylindrical portions of standard pollen product, as provided in the Natupol® Excel product to support the population during the incubation period (about 5 g / day). Based on experience, a maximum of 45 g at a time was provided to the colonies to prevent excessive use of pollen. Thus, if an incubation would exceed 15 days (e.g. T2) a feeding tunnel was installed in the lid (see also T7 and T8 below) via which additional pollen cylinders could be added without opening the lid. Care was taken to make the feeding tunnel gastight, by securing a tight fit in the lid and by tightly enclosing its exterior parts in a gastight bag. In addition to the pollen food source, about 1.9 liter of Koppert’s standard sugar solution (66° brix) for bumblebees, as provided in the sugar solution bag of the Natupol® Excel product, was accessible in the brood chamber via a standard feeding wick. For the nestboxes of T1-T4, the sugar solution bag was positioned in the ventilation chamber, for the Natupol® Excel nestbox, it was in its standard position (under the plastic confinement for the bumblebees).

[0099] For all treatments the CO2 concentration, the percentage Relative Humidity (RH) and the Temperature (T) ware measured, logged and stored on a computer system for analysis using a RFC02RHTemp2000A data logger (Madgetech®, Warner (NH), USA) in accordance with the supplier’s instructions. For all treatments the data logger was positioned in the higher area of the nestbox, connected to the lid.

[0100] During the incubations the exterior of the nestboxes was visually inspected regularly for possible escape points. After the incubations the nestboxes were frozen (-20°C, 24 h) and the bumblebee colonies and broods were visually inspected and photographically recorded before and after the adult individuals were removed.

[0101] Results and discussion

[0102] Figure 6 shows the results for the CO2, %RH and Temperature recording for the different treatments (T1-T5) together with pictures of the colonies at the end of the incubations (recorded before and after the adult individuals were removed). A summary of the results is presented in table 1 below. The summary includes the values of the graphed minimum and maximum of the different data collections. It should be noted that where such minimal and maximal values are presented in the experiments, they do not necessarily have a significance for the obtained results. They are merely presented to help to (mathematically) evaluation the data presented in the graphs. Table 1: Summary of Environmental Conditions and Colony Health

[0103] *14.8 days = 14 days and 20 hours

[0104] **1.4 days = 30 hours

[0105] The results confirm the surprising finding of the invention that confinement of a bumblebee population comprising adult workers is possible for a prolonged period using carboard barriers only for the bumblebee confinement. The health and development of the bumblebee population is best supported by the use of the combination of an open-ended container together with a lid, multi-layered barrier sheet having ventilation openings in one sheet connected to the interstitial space and a ventilation chamber using open ventilation openings (Tl) in accordance with preferred embodiments of the invention. Separately and in sub-combinations, these elements already provide benefits.

[0106] The T2 treatment, was longer (23 days) than the Tl treatment (14 days), as the surprisingly good results of the Tl treatment indicated that a longer confinement of the bumblebee population would be possible. In comparison to Tl and T5, T2 resulted in suboptimal results with some reduction of brood at the end of its test period. It is expected that the population can recover from this level of brood reduction at the pollination location, where the number of passageways are opened to allow the adult workers to exit end re-enter the nestbox, which increases ventilation and decreases CO2 accumulation. It is further expected that the brood reduction will be lower at shorter times of confinement (e.g. 3-14 days). Overall, a setup of a cellulose board nestbox analogous to T2 will be able to maintain a bumblebee population for at least up to 23 days, such as at least 3-14 days. Although the T1 treatment was for 14 days, looking at the results for the T2 treatment, it will be clear that the bumblebee population can be maintained for at least 23 days in the nestbox of this T1 treatment, with a better result than obtained for the T2 treatment.

[0107] The results also confirm the surprising finding that the gas permeability of cardboard is sufficient to maintain a bumblebee population during the time periods that are required for their transport from production to a pollination locations (in general 3-10 days, most frequently 3-5 days). The water condensation effects in the T3 treatment were not noticeable in the first part (up to 10 days) of the test period as it was at the end (14.8 days). The brood reduction in this first period is expected to be acceptable and the population can recover from this at the pollination location, where the number of passageways are opened to allow the adult workers to exit end re-enter the nestbox, which reduces CO2 accumulation and increases ventilation.

[0108] It may further be expected that a hive constructed from cellulose board barrier sheets, comprising an open box with a separated lid, wherein gas passages are present between the lid and the body of the open box (analogous to figure 4B with only bottom part sealed), will have gas exchange capabilities intermediate of T1 and T2. Thus, it may be expected that a bumblebee population can also be maintained in such a cellulose board nestbox for up to at least 23 days. The results from T7 / T8 discussed below also confirm this.

[0109] Treatment 6

[0110] This experiment aimed to monitor interior conditions and colony survival / health in a cardboard nestbox depending only on gas exchange via the cardboard barrier sheets. For this, all the ventilation openings were closed similar to T3. The objective was to simulate real-world bumblebee transportation and environmental conditions experienced by bumblebee colonies within a nestbox after the arrival to the outdoor pollination location.

[0111] The only means of air passage was through the cardboard barrier sheets during the transportation (storage). During the outdoor phase ventilation was also possible via the opened passageway. The study was conducted under laboratory conditions for 3 days (with passageway in closed state) followed by 14 days under outdoor conditions (with passageway in opened state).

[0112] The experiment of this treatment was conducted in analogy of treatment T3. Similar to the other treatment, a bumblebee colony with a similar composition was selected from Koppert’s Natupol Excel Hive production. The main difference with the T3 treatment was that after day 3, the housing was transferred outdoors, and the passageway was transformed from the closed state to the open state. Sufficient pollen was provided in the brood chamber to support the colony for the full duration of the experiment.

[0113] Results and discussion

[0114] The results of the logged data are presented in figure 6P. graphed data T6 (fig 6P):

[0115] Relative Humidity (%): graphed minimum =29.84, graphed maximum =81.36

[0116] CO2 (ppm): graphed minimum =1320, graphed maximum =20000

[0117] Temperature (°C): graphed minimum =0, graphed maximum =48.56

[0118] The data shows that in the 3-days storage simulation, the development of CO2 levels, Relative Humidity and Temperature are comparable to the first 3 days of the T3 treatment.

[0119] Summary for indoor storage phase

[0120] -CO2 Levels: 20,000-26,000 ppm

[0121] -Humidity: 66-75% RH

[0122] -Temperature: 25 °C

[0123] The opening of the passageway on day-3 initially significantly decreases the CO2 level. The outdoor conditions during the experiment were unfortunately extreme and a high temperature, in particular on the second day caused death of the queen (observed outside the nestbox). Frequent rains were also encountered during the outdoor period. Summary of outdoor period

[0124] CO2 Concentration: Daytime: Around 2,300 ppm, after sunset: 10,000-20,000 ppm. Minimum CO2 levels rose during rainy days, peaking at 5,000 ppm during the day and 35,000 ppm at night. Inability to leave the nestbox likely caused CO2 accumulation.

[0125] Humidity: The box absorbed moisture due to rainfall, leading to condensation. The gas impermeable foil used in the experiment probably also added to moist accumulation. During rainy days, internal humidity increased from 60% to 70%, and.

[0126] Temperature: Extreme high maximum of 48,5°C in early phase. Temperatures during rainy periods ranged from 20-25°C at night to around 30°C during the day.

[0127] In general, it may be concluded that a bumblebee housing with the characteristics of this treatment is suitable for confining a bumblebee population for at least 3 days while the passageway is in a closed state. Also in view of the results of T3, it is reasonable to expect that this may be extended up to at least 10 days. When the housing would be placed in a more moderate environment, such as in a greenhouse, or when it is shielded from environmental conditions, such as direct sunlight and rain, it may be expected that it will have a better performance relative to what is obtained in the present test. Thus, based on this experiment it may be expected that a bumblebee housing constructed from cardboard is suitable for confining bumblebees in the context of bumblebee pollinator colony products.

[0128] Treatments T7 and T8

[0129] This experiment was setup to evaluate the gas exchange between an open-ended container, such as folded from a blank shown in figure 1A, or a similar blank, and a lid suitable for closing such an open-ended container, such as a lid folded from a blank shown in figure IB, or a similar blank. For this, for both treatments T7 and T8, the blank of figure 1A was modified. In the modified blank ventilation openings (4) in the ventilation chamber and ventilation openings (5) in the brood chamber were not cut out. In addition, the gas connection existing between bottom panels A0 / A0’, B0, C0 / C0’ and DO were closed off in a similar way as was done in the T3 treatment, but with a smaller surface of gastight foil, since the ventilation openings (4) in the brood chamber did not have to be closed (see figure 7A an 7B). It should be noted that because a sugar water bag (volume 1.9 liter) was present in the ventilation chamber, the available additional gas volume in the ventilation chamber was relatively small.

[0130] For treatment T7 a ventilated lid similar to the blank of figure IB was used (see figure 7B). For treatment T8 a modified blank was used, wherein the ventilation openings (6) in panel HO and cutouts (7), (9) in panels EO, Hl / H-1 are not included (see figure 7A). This modified lid (see figure 7A) thus does not have ventilation openings that facilitate gas exchange between the brood chamber and the exterior of the brood chamber.

[0131] For treatment T8 gas exchange between the brood chamber and the exterior of the housing depended fully on the gas connections that existed between the lid and the walls of the open-ended container. In treatment T7 additional gas exchange is provided via the ventilation openings (6) in the brood chamber, which via an interstitial space are in connection with ventilation openings (7) connecting to the exterior of the bumblebee housing as a whole.

[0132] The treatment was conducted similar to treatment T2 using a bumblebee population of similar composition, similar incubation conditions and the same date loggers.

[0133] Light:dark exposure for the T7 and T8 treatments was 8hours:16 hours. As it was intended to continue the experiment for over 14 days, a feeding tunnel (see figure 7C) was installed in the lids of the housings of T7 and T8. The feeding tunnel consists of a 3D-printed cylinder connected to a flange on one side. For installing the feeding tunnel a tight fitting circular cutout is made in the lid and the cylinder is pushed through the cutout with the flange pushed to the interior side of the lid. A removable fitting piston (see figure 7C) closes the open side of the cylinder on the exterior side. Via the feeding tunnel additional pollen can be introduced into the brood chamber while bumblebees are confined, making prolonged confinement possible without overfeeding. At the start of T8 and T7 the colonies were provided sufficient pollen for 14 days (6x15g standard pollen product as used in Natupol® Excel). It was the intention to continue the "experiment beyond 14 days.

[0134] Results and discussion Intermediate date was logged on day 10. The logged CO2, RH and Temperature values for T7 and T8 are presented in figures 6D and E respectively. For neither T7 nor T9, visual inspection of the housing shows any escapes or damage caused by bumblebees that potentially could lead to escape. Auditive inspection by experienced personnel for both T7 and T8 indicated healthy active populations inside the housings. graphed data T7 (fig 7D):

[0135] Relative Humidity (%): graphed minimum =59.2, graphed maximum =75.84

[0136] C02 (ppm): graphed minimum =1760, graphed maximum =21920

[0137] Temperature (°C): graphed minimum =21.12, graphed maximum =29.36 graphed data T8 (fig 7E):

[0138] Relative Humidity (%): graphed minimum =58.32, graphed maximum =85.76

[0139] C02 (ppm): graphed minimum =1190, graphed maximum =19850

[0140] Temperature (°C): graphed minimum =21.28, graphed maximum =29.36

[0141] Treatment T9

[0142] The experiment was setup to reconfirm earlier findings that points of light entry are escape points for bumblebee individuals. For this two holes of 4.0 mm diameter were drilled in panels Cl and C2 of the open-ended container folded from the blank of figure 1A. The holes pierced trough both panels CC2 and Cl and were drilled at a location that was easily accessible for the bumblebee individuals (see figure 8A). The open-ended container was combined to a fully functional bumble bee housing with a lid folded from a blank similar to the blank of figure IB. A sugar water bag was installed in the ventilation chamber and the wick was properly installed such that access to it was provided in the brood chamber.

[0143] The treatment was conducted similar to treatment T1 using a bumblebee population of similar composition. Pollen was provided in sufficient amount (3x15g). The incubation conditions and the incubation period differed from Tl, as the bumblebee housing was incubated for 3 days at laboratory conditions (22°C, 50-60% RH) under a light regime of light:dark 8h:16h. After that during days 4-7 the housing was placed outdoors (temperatures ranging from 15-32°C). During the incubation period, the exterior of the housing was regularly visually inspected. After the 7 days incubation the housing was frozen for 24h at -20°C and the brood chamber was visually inspected, in particular at the location of the drilled holes.

[0144] Results and discussion

[0145] From the outside it was already on day 5 visible that one of the drilled holes was enlarged and an attempted escape from the brood chamber confinement was clearly visible in that an individual got stuck in the enlarged hole via which it attamed to escape. The visual inspection of the interior confirmed enlarging damage to both of the drilled holes. A picture of panel C2 after the incubation and removal of the stolp bottom is presented in figure 8B. The position of the holes has been marked with a circle.

[0146] The experiment confirms that escape of bumblebee is triggered by light points, such as ventilation openings puncturing trough barrier material used to confine bumblebees.

[0147] Treatment T10

[0148] The nestbox of this experiment is assembled from an open container folded from a blanks similar to the one of figures 4A and a lid folded from a blank similar to the one of figure 4B. Pictures of the nestbox used are shown in figures 9A and 9B. The experiment was carried out similar to Tl. The quality of the colonies was the same as from Natupol Excel Hives (Queenright colonies from Bombus terrestris spp. lerreslris). Colonies met the standard in quantity and quality of individuals, living QQ and brood (workers average 120 (range 80-150)). Colonies were fed 45g of pollen presented in 3x15g portions and sugar water (volume about 1.9-2.0 liter) positioned in the ventilation chamber and accessible in the brood chamber via a wick. In the experiment the bumblebees were confined during 10 days under constant exterior light conditions (24h light) with the nestbox placed under constant airflow, maintaining consistent environmental pressure to trigger escape. During the incubation period, the exterior of the housing was regularly visually inspected. After the 10 days incubation the housing was frozen for 24h at -20°C and the brood chamber was visually inspected. Results & Discussion

[0149] Throughout the 10-day trial, no bumblebee escapes were observed. Such a 10-days confinement period in practice will be sufficient for the time required for expedition of the hives from the production facility to their polination location. Inspection of the interior of the nestbox showed complete pollen consumption. This indicating colony hunger due to pollen shortage and resulted in larval expulsion. At the same time this shows the ability of the colony to develop within the closed nestbox. A picture of the interior of the nestbox at the end of the incubation and the frozen colony is presented in figure 9C.

[0150] Treatment Til

[0151] In this test the use of fondant as an alternative sugar source instead of sugar water was tested. The nestbox of this experiment is assembled from an open container folded from a blanks similar to the one of figures 4A and a lid folded from a blank similar to the one of figure 4B. The duration of confinement was 8 days. In view of the provision of fondant no sugar water bag was placed in the ventilation chamber. The opening for the wick in the brood chamber was sealed by glueing a cardboard strip on top of it.

[0152] Fondant was provided in two different formats. In a first format in a cartridge (figure 10A, 10B, IOC) formed by a box having a relatively small opening. In a second format in an open tray having a tub-like structure with an open end over its full length (figure 10D, 10E, 10F). At the end of the 8-days confinement period the cardboard hive lid was removed to evaluate the flight ability of the bumblebees. The test was largely performed similar to T10 with only deviations in sugar source used, incubation time and end evaluation.

[0153] Results & Discussion

[0154] The trial demonstrated that fondant can be used as an alternative energy source for bumblebee colonies. The cardboard hive maintained adequate environmental conditions without mold or excessive moisture. The flight test confirmed that the colonies remained viable after 8 days of confinement, indicating resilience beyond standard limits. The brood appeared dry, with mostly adult individuals and pupae. Large larvae present. Small, middle larvae and eggs were sporadically found. Fondant feeding from the open tray resulted in a more active colony. Fondant consumption was higher when using the open tray. Pollen consumption was higher (but still in the low range max 15 g) when feeding fondant from the open tray. Pictures of the colonies taken at the end of the trial are presented in figures 10G (cartridge) and 10H (open tray).

[0155] Field trial

[0156] The suitability of the bumblebee nestbox of the invention for shipping bumblebee colonies and subsequent housing during pollination activities at a pollination location was further confirmed in this experiment.

[0157] The nestboxes of this experiment were assembled from an open container folded from a blanks similar to the one of figures 1A and a lid folded from a blank similar to the one of figure IB. Three cardboard hives were prepared for shipment, each containing a standard sugar solution (66°brix, volume about 1.9-2.0 liter) in plastic bag and 3 units of standardized Koppert 's pollen (each 15g) as provided in the Natupol Excel hives from Koppert (Berkel en Rodenrijs, NL). Colonies were from the same composition and quality as the Natupol Excel Hives of Koppert (Queenright colonies from Bombus terrestris spp. terrestris). Colonies met the standard in quantity and quality of individuals, living QQ and brood (workers number average 120 (range 80-150)). Secured shipping was from Koppert Slovakia (Nove Zamky) to Koppert Spain (Almeria) under controlled conditions suitable for bumblebee transport. After transport, the colonies were transferred to a controlled R&D greenhouse facility with sweet peppers (SP) and strawberry (S) crops to observe their viability and pollination effectiveness. The expedition time duration (start expedition to pollination start) was 4 days. Pictures of the nestboxes prior to shipping before installation of the bumble colonies are shown in figure 11 A.

[0158] On arrival at the R&D greenhouse facility and opening of the confinement of the bumblebees was ended by opening the nestbox door (passageway). The bumblebee workers showed sufficient viability and pollination activity was satisfactory, though pollen availability in the crops was scarce. In view of pollen scarcity in the crops, pollen cartridges were introduced to the crops as an additional food source for the bumblebees. The experiment concluded 18 days after the start of the polination, because the greenhouse management decided to remove the SP and S plants. Bumblebee colonies were frozen for further analysis. This analysis showed that all developmental stages, including queens, were present and alive before freezing. Some signs of colony starvation were observed by larvae removal. This is assumed to be casued by scarcely of pollen source. A large amount of sugar solution remained in honey pots, indicating colony activity. Moisture accumulation was within tolerable levels. Overall, the colonies transported and housed in the nestbox of the invention met viability and pollination efficiency standards. The results of this test confirm that it is reasonable to expect that bumblebees can be housed in nestbox of the invention up to at least 40 days and even up to at least 60 or days. A picture of one of the nestboxes after freezing is shown in figure 1 IB. The other nestboxes showed a similar colony quality.

Claims

Claims1. Housing, such as a nest box, for bumblebee (Bombus spp.) individuals, preferably including adult bumblebee workers, comprising:(i) a number of barriers, preferably barrier panels, formed from sheets of barrier material, preferably selected from cellulose board, such as corrugated cardboard, or solid cardboard;(ii) a number of chambers, including a brood chamber, suitable to accommodate the presence of adult bumblebee individuals, preferably workers, more preferably workers together with larval brood, enclosed by the barrier material, wherein said brood chamber has a volume (Vbc), preferably a volume (Vbc) of between 0,7- 103- 98- 103cm3;(iii) a number of passageways for the bumblebee workers between the brood chamber and the exterior of the bumblebee housing, said number of passageways having a closed state and an open state, each passageway in the open state having an area (Apw), preferably an area (Apw) of between 0,50-36,0 cm2, more preferably 0,75-16,0 cm2; wherein preferably, when the number of passageways are in the closed state, there are no direct connection between the interior of the brood chamber and the exterior of the brood chamber, wherein a direct connection is a connection that allows light to enter into the brood chamber.

2. Housing according to claim 1, wherein cellulose board comprises > 50%, such as > 70%, > 80%, > 85%, > 90%, > 95%, of the total weight of solid materials used in the housing, preferably 70%-100%, such as 70%-97%, or 75-90%.

3. Housing according to any of the preceding claims, wherein the barrier material enclosing the brood chamber contains a plurality of layers, such as a double layer, of adjoining barrier panels, preferably adjoining layers of cellulose board sheets, most preferably adjoining sheets of corrugated cardboard.

4. Housing according to claim 3, wherein in adjoining barrier panels a number of ventilation openings are provided in at least one barrier panel, such as in the inner layer panel or in the outer layer panel wherein(i) a number of parallel adjoining further panels of barrier material blocks the openings in the first panel and / or (ii) when ventilation openings are provided in both of adjoining barrier panels, a ventilation opening in a barrier panel contacting the brood chamber does not overlap with a ventilation opening in the adjoining barrier panel.

5. Housing according to any of the preceding claims, comprising a further chamber, the ventilation chamber, enclosed by barrier material and preferably comprising a number of ventilation openings, more preferably a number of open ventilation connections with the exterior of the housing, wherein the brood chamber borders the ventilation chamber and is in gas connection with said ventilation chamber, preferably via gas passages that allow gas exchange between the brood chamber and the ventilation chamber, while restricting access of the bumblebee workers from the brood chamber to the ventilation chamber, such as gas passages having a maximal width of at most 7,0 mm, such as at most, 6.5, 6.0, 5.5, 5.0, 4.5, 4.0, 3.5, 3.0, 2.5, 2.0, 1.5, 1.0, 0.9, 0.8, 0.7, 0.6, or at most 0.5 mm, preferably having a maximal width of 0.2 - 3.0 mm, such as 0.2-2.5 mm or0.2-2.0 mm.

6. Housing according to claim 5, wherein gas passages are formed at interfaces, such as at comers, of joining barrier panels, such as by slits and / or cracks and / or openings formed at such interfaces due to fitting tolerances.

7. Housing according to any of the preceding claims, wherein a container comprising a food source, such as an aqueous sugar solution, for the bumblebee workers is placed in a ventilation chamber and access to the food source is provided in the brood chamber, for example by using a wick.

8. Housing according to any of the preceding claims, comprising in the brood chamber, preferably while the passageway is in the closed state, a population of bumblebee individuals, wherein the bumblebee population density in the brood chamber is at least 0.003 bumblebee adult individuals per cm3, preferably O.OO3-O.188 bumblebee adultindividuals per cm3, such as 0.013-0.039, 0.008-0.042, 0.004-0.011, 0.003-0.014, 0.046- 0.109, 0.071-0.236, 0.012-0.055 preferably 0.01-0.10 bumblebee adult individuals per cm3.

9. Housing according to any of the preceding claims, wherein the brood chamber is assembled from a plurality of elements including a first container element comprising an open receiving end and a second closing element suitable to close the open receiving end of the container element, wherein preferably gas connection between the brood chamber and the exterior of the brood chamber is formed in the closure of the receiving end by the closing element.

10. Housing according to any of the preceding claims, wherein the housing is formed from a number of folded blanks formed from the barrier material, wherein preferably the housing is formed from a plurality of blanks, such as a first blank folded to an open- ended container comprising the brood chamber having an open end, and a second blank folded to a closing element, such as a lid, configured to close the open end of the brood chamber.

11. Housing according to any of the preceding claims, wherein in the open state of the number of passage ways the sum of the areas (XApw) of the number of passage ways in the open state is > 10%, such as >15%, >20%, >25%, > 30%, >40%, >45%, >50%, >55%, >60%, >65%, >70%, 75%, >80%, > 85%, >90%, >95% of the total area (Agc) of gas connections between the brood chamber and the exterior of the brood chamber.

12. Housing according to any of the preceding claims, wherein barrier material contacting the brood chamber does not comprise a cellulose board laminated with a polymeric material.

13. Housing according to any of the preceding claims, wherein the surface of barrier material, in particular barrier material enclosing the brood chamber, has an indentation microhardness of less than 60 MPa, such as < 50MPa, preferably < 40 MPa and / or a tensile strength of less than 20 MPa, such as such as < 15 MPa, preferably < 10 MPa.

14. Housing according to any of the preceding claims, wherein a number of carbohydrate food sources is provided to bumblebee individuals and wherein preferably any provided carbohydrate food source has a solid content of 70% -99% (w / w) based on the total mass of the food source composition, such as 75%-95%, preferably 80%-95%, such as 85%-93% based on the total weight of the food source composition, for example sugar fondant.

15. Use of a housing according to any of the claims 1-14 for confining bumblebees, in particular adult bumblebee individuals, preferably workers, more preferably workers together with larval brood.

16. Use according to claim 15, wherein the housing is suitable for confining the bumble bees, in particular adult bumblebee individuals, preferably workers, more preferably workers together with larval brood, for at least up to 3-7 days, preferably up to 8, 9, 10 or 12 days, while the number of passageways are in a closed state and / or for housing bumble bees, in particular adult bumblebee individuals, preferably workers, more preferably workers together with larval brood for at least up to 14 days, such as at least up to 21, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75 days and preferably up to 90 days, while a passageway is in an open state.

17. Method of pollinating blooming plants comprising providing in the vicinity of the plants a number of bumblebee housings according to any of the claims 1-14 having an opened bumblebee passage and allowing bumblebee workers to pollinate the blooming plants.

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