Apparatus for breeding natural enemy insects, method for breeding natural enemy insects, and method for controlling difficult-to-control microscopic pests

Abstract

To provide a growth device of natural enemy insects which is improved so that growth of Phytoseiidae being the natural enemy insects is improved in comparison with a conventional growth device of natural enemy insects for contributing to the spread of IPM, the number of discharge of Phytoseiidae from the device is increased and a release period is caused to protract as much as possible more suitably, and further provide a growth device of natural enemy insects which enables growth of two kinds of different natural enemy insects simultaneously.SOLUTION: In a body part which has a closed space which a natural enemy insect can enter and exit, a natural enemy insect, food ticks which become the food of the insect, a small bag-like member, containing the food of the food ticks, a member from felt for laying eggs, and water retention materials which consist of water retaining materials with the gradual moisture release property are arranged at least, the natural enemy insect is one kind of Phytoseiidae, and the food ticks are at least Carpoglyphidae, and the aforementioned water retention materials include foods that retain water by using an aqueous solution containing sugars.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a breeding device for natural enemy insects, a breeding method for natural enemy insects using the device, and a method for controlling difficult-to-control micro-pest insects. More specifically, the present invention relates to a breeding device for natural enemy insects that can maintain the breeding of phytoseiid mites, which are natural enemy insects, for a longer period of time than conventional devices and increase the number of phytoseiid mites released. Furthermore, in a preferred embodiment of the present invention, the present invention relates to a useful technology that advances the practical application of integrated pest management (IPM) by enabling effective control of pests using natural enemy insects both above and below ground in plants, which has not been done before. In particular, the present invention relates to a technology that uses phytoseiid mites of the Phytoseiidae family belonging to the suborder Gamagomata, exemplified by Phytoseiulus swirskii, as natural enemy insects, and, if necessary, a useful technology that enables the use of Gamagomata of the Phytoseiidae family belonging to the suborder Gamagomata in the same device. [Background technology]

[0002] Hard-to-control micro-pests (hereinafter referred to as micro-pests or pests) such as thrips, spider mites, and whiteflies are important pests that cause damage to many greenhouse horticultural crops (hereinafter referred to as greenhouse vegetables or crops). Micro-pests are difficult to control with chemical pesticides, and biological control using natural enemy insects, such as phytoseiid mites, has been practiced both domestically and internationally. Considering food safety and the impact on producers' health, biological control using natural enemy insects instead of pesticides has attracted attention as integrated pest management (IPM). IPM is a pest management method that uses polyphagous phytoseiid mites, such as Phytoseiulus californicus, Phytoseiulus swirskii, and Phytoseiulus cucumeris, as natural enemies to control plant pests. These mites feed on the target pests, such as spider mites and thrips.

[0003] Here, phytoseiid mites are vulnerable to changes in the cultivation environment, such as drought and chemical sprays, and in order to achieve stable pest control effects, it is necessary to release a large number of natural enemy insects over a long period of time. Known formulations for this purpose include "packed formulations" in which natural enemy insects are contained in bags and "bottle formulations" in which natural enemy insects are contained in bottles. Conventional bottled and packed formulations cannot adequately mitigate the effects of environmental changes, and therefore, there has been a problem in that the effectiveness of using natural enemy insects is not stable when used in greenhouse horticultural crop cultivation in Japan.

[0004] It is known that polyphagous phytoseiid mites, which can be used as natural enemy insects, multiply when the above-mentioned pest insects that serve as their natural food are absent or in limited numbers and are provided with so-called prey mites as an alternative food source. Taking advantage of this fact, various breeding devices for natural enemy insects have been proposed as natural enemy support materials. These devices are called Bunker Sheets (registered trademark) and have already been put into practical use. The applicant of the present application jointly developed this new natural enemy support material (Banker Sheet) and has promoted the spread of IPM using phytoseiid mites as natural enemy insects, mainly for greenhouse vegetables such as strawberries and cucumbers.

[0005] As described in Patent Document 1, a breeding device for natural enemy insects basically has the following configuration: It has a main body with an internal space sealed to the extent that it can serve as a hiding place for natural enemy insects (shelter from rain, watering, pesticides, etc.), and is equipped with a bag (natural enemy insect storage section) in which natural enemy insects are stored so that they can enter and exit, and an egg-laying section in which the natural enemy insects can lay eggs. It also describes that the natural enemy insects are stored in the bag in the natural enemy insect storage section, in combination with food such as bait mites necessary for the propagation of the natural enemy insects. As mentioned above, the bag containing the natural enemy insects is called a "pack preparation."

[0006] For the purpose of more effectively utilizing the natural enemy insects contained in the bag, the pack preparation is placed in the internal space of the main body of a breeding device for natural enemy insects configured as described in Patent Document 1 and is used as the "natural enemy insect storage section" of the device. Of course, the pack preparation can also be used and is used alone as is for releasing natural enemy insects. To enhance convenience in this case, some pack preparations are equipped with a part for attaching to plants. Widely used pack preparations include, for example, the Miyako Phytoseiulus californicus pack preparation, which contains Miyako Phytoseiulus californicus, a mite that preys on spider mites, in a bag, and the Swartskii Phytoseiulus swartskii pack preparation, which contains Phytoseiulus swartskii, a mite that preys on whiteflies and thrips, in a bag. Both of these pack preparations contain one type of natural enemy insect selected from phytoseiid mites, and the natural enemy insect selected according to the intended use is used.

[0007] Patent Documents 2 and 3 propose providing a member made of a moisture-sustaining material with a sustained-release property in the enclosed space of the main body. They also state that a highly absorbent resin is suitable as the moisture-sustaining material. They also state that by providing a moisture-sustaining material that provides an appropriate humidity level, the relative humidity within the enclosed space of the main body can be maintained at 70% or higher for a long period of time, preferably at 80% or higher, thereby creating a suitable habitat for natural enemy insects and their prey mites. Therefore, installing a moisture-sustaining material is effective in promoting and maintaining their populations. As described above, Patent Documents 2 and 3 state that the use of a moisture-sustaining material with a sustained-release property can maintain the environment within the enclosed space of the main body as a high-humidity environment suitable for the habitat of natural enemy insects and prey mites. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 5681334 [Patent Document 2] Japanese Patent Application Publication No. 2018-29591 [Patent Document 3] Japanese Patent Application Publication No. 2018-29589 Summary of the Invention [Problem to be solved by the invention]

[0009] In response to the above-mentioned conventional techniques, the present inventors believe that the widespread adoption of integrated pest management (IPM) is urgently needed as a means of reducing the use of pesticides, ensuring food safety, and reducing the potential for health damage to agricultural workers. It is important to extend IPM beyond the currently used greenhouse vegetables and to expand its application to a wider range of crops in the future. The present inventors recognized that, to achieve this, it is necessary to enhance the functionality of existing natural enemy insect breeding devices (natural enemy support materials), particularly to improve the breeding efficiency of natural enemy insects, and in particular to improve the number of insects released from the natural enemy support materials. Specifically, it is necessary to develop a technology that allows natural enemy insects to stably breed and live within the natural enemy support material, thereby enabling natural enemy insects to be stably released from the natural enemy support material for a longer period of time, thereby effectively contributing to pest control.

[0010] The breeding devices for natural enemy insects currently in practical use are highly water-resistant, have good airtightness and egg-laying sites, and function as shelters for natural enemy insects. They are more durable than the aforementioned commercially available pack formulations directly attached to plants, and are said to be able to be used for a long period of time. In addition, if the breeding of natural enemy insects can be carried out stably for a longer period of time than when using conventional devices, and the release conditions of natural enemy insects can be maintained in good condition for a long period of time, the frequency of replacement of the breeding device can be reduced, which is advantageous in terms of cost, and the burden on farmers for installing the device can be greatly reduced, making it more useful.

[0011] The inventors also recognized that while the above-mentioned natural enemy insect propagation device is designed to control aboveground pests whose natural enemy is phytoseiid mites, damage caused by pests such as fungus gnats that feed on underground parts is significant, and that in recent years there has been a demand for the widespread use of IPM (integrated pest management) for these pests as well. In particular, the inventors believed that if it were possible to improve existing natural enemy insect propagation devices (natural enemy support materials) so as to simultaneously control pests such as thrips and spider mites that feed on aboveground parts and pests such as fungus gnats that feed on underground parts without making major changes, the added value of the natural enemy insect propagation devices (natural enemy support materials) could be significantly increased, which would greatly contribute to the widespread use of IPM (integrated pest management).

[0012] Therefore, in view of the above-mentioned recognition, the first object of the present invention is to improve a conventional breeding device for natural enemy insects (natural enemy support material) with a simple configuration, thereby promoting the breeding of natural enemy insects, particularly phytoseiid mites (increasing the number of released mites) compared to conventional devices, in order to contribute to the spread of IPM (integrated pest management). The second object is to improve the number of phytoseiid mites released from the natural enemy support material and to extend the release period as long as possible, preferably so that phytoseiid mites are stably breeded over a longer period of time (extending the release period). The final object of the present invention is to develop technology that can provide a useful breeding device for natural enemy insects that improves economic efficiency and contributes to reducing the workload of farmers by improving the release of phytoseiid mites, a natural enemy insect, as described above.

[0013] Furthermore, another object (third object) of the present invention is to improve upon conventional natural enemy insect propagation devices (natural enemy support materials) used for phytoseiid mites by using a simple configuration, thereby developing an all-in-one device that can efficiently propagate both phytoseiid mites and other natural enemy insects with different ecologies from phytoseiid mites, something completely unimaginable with conventional devices, and can be used to control different pests in a wider range of areas, both aboveground where phytoseiid mites control pests and underground where phytoseiid mites cannot control pests. The realization of such an all-in-one natural enemy insect propagation device will provide a useful technology that can greatly contribute to the spread of IPM (integrated pest management). Hereinafter, natural enemy insect propagation devices (natural enemy support materials) will sometimes be referred to simply as Bunker Sheet (registered trademark) as a representative example. [Means for solving the problem]

[0014] The above object can be achieved by the present invention, which provides the following breeding device for natural enemy insects. [1] A breeding device for natural enemy insects for improving the breeding of natural enemy insects that are natural enemies of difficult-to-control micro-pests, characterized in that the device contains at least the following inside a main body having an enclosed space through which the natural enemy insects can enter and exit: natural enemy insects; bait mites that serve as food for the natural enemy insects; a small pouch-shaped member containing at least food for the bait mites; a felt member for laying eggs; and a moisture-retaining material consisting of a moisture-slow-releasing water-retaining material; the natural enemy insects are phytoseiid mites of the family Phytoseiidae belonging to the suborder Gamasidae, a representative example of which is Phytoseiidae Swirlskii; the bait mites are at least sugar mites of the family Sugar mite belonging to the suborder Acaridae, a representative example of which is Carbuncle mite; and the moisture-retaining material contains bait that has been moistened with an aqueous solution containing sugars.

[0015] Preferred embodiments of the above-mentioned natural enemy insect breeding device are as follows. [2] The bait mites further include a type of acarid mite of the Astigmatidae family belonging to the suborder Acaridae, of which Astigmatism is a representative example, and the device for breeding natural enemy insects described in [1] above is configured so that the initial density of the acarid mite is smaller than the initial density of the sugar mite. [3] The breeding device for natural enemy insects described in [2] above, wherein the initial density of the sugar mites is 1,000 and the initial density of the astigmatids is 2 to 40. [4] A breeding device for natural enemy insects described in any one of [1] to [3] above, wherein the sugar is at least one selected from the group consisting of trehalose, honey, brown sugar, molasses, glucose, fructose, sucrose, sorbitol and erythritol. [5] A breeding device for natural enemy insects described in any of [1] to [4] above, wherein the water-retaining material contains food that has been kept moist using an aqueous solution containing a substance that contains a nitrogen component in addition to the sugars. [6] The breeding device for natural enemy insects according to [5] above, wherein the substance containing a nitrogen component is at least one selected from the group consisting of urea, peptone, yeasts, amino acids and vitamins. [7] A breeding device for natural enemy insects described in any of [1] to [6] above, wherein the water-retaining material is a granular water-retaining material made of a highly water-absorbent resin, and five pieces are made to retain water so that the total weight is adjusted to 4 to 7 g. [8] The natural enemy insect breeding device according to any one of [1] to [7] above, wherein the natural enemy insects further include Gamasid mites of the Gamasidae family belonging to the Gamasida suborder, and the initial density of the Gamasid mites is 1 to 3 per 100 of the one type of phytoseiid mites.

[0016] In another embodiment, the present invention provides the following method for propagating phytoseiid mites. [9] A method for breeding phytoseiid mites to improve the number and duration of release of natural enemy insects, which is used when using natural enemy insects to control difficult-to-control micro-pests, characterized in that the method is configured to maintain an increase in the population of phytoseiid mites, which are natural enemy insects, for a long period of time using the natural enemy insect breeding device described in any of [1] to [7] above.

[0017] In another embodiment, the present invention provides the following method for propagating phytoseiid mites and Gamasid mites.

[10] A method for breeding phytoseiid mites and Gamas mites, which is used when using natural enemy insects to control difficult-to-control micro-pests, and which involves releasing both natural enemy insects, phytoseiid mites and Gamas mites, characterized in that the method is configured to use the natural enemy insect breeding device described in [8] above to increase the number of phytoseiid mites, and then increase the number of Gamas mites after the breeding of the phytoseiid mites has weakened.

[0018] In addition, the present invention provides, as another embodiment, the following method for controlling difficult-to-control microscopic pests.

[11] A method for controlling difficult-to-control micro-pest insects, comprising installing the propagation device for natural enemy insects according to any one of [1] to [8] above in an area where the difficult-to-control micro-pest insects live. [Effects of the Invention]

[0019] According to the present invention, a conventional natural enemy insect breeding device (natural enemy support material) is improved with a simple configuration. First, the use of a water-retaining material containing bait promotes the breeding of natural enemy insects compared to conventional devices. Second, a preferred embodiment of the present invention, which utilizes an improved configuration of the bait mites, allows breeding to occur stably over a longer period of time, making it possible to increase the number of natural enemy insects released and to extend the release period as long as possible. These effects of breeding and / or extending breeding periods provide a natural enemy insect breeding device that can improve economic efficiency and reduce the workload of agricultural workers. Third, according to the present invention, which is configured to utilize two types of natural enemy insects, a conventional natural enemy insect breeding device (natural enemy support material) is improved with a simple configuration, providing an all-in-one natural enemy insect breeding device that can be used to control different pests over a wider area, both above and below ground, using the same device, something that was completely unthinkable with conventional devices. As mentioned above in points 1 to 3, the present invention provides a useful technique that can greatly contribute to the spread of IPM (integrated pest management). [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a graph showing the effect on the release status of Phytoseiulus swirskii by saccharides and the like introduced into the water-retaining material constituting the breeding device for natural enemy insects of the present invention. [Figure 2] 1 is a graph showing the release status of Hypoaspis sp. swirskii mites and a small number of Hypoaspis sp. mites when they are added to a pack formulation that constitutes the natural enemy insect propagation device of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] The present invention will be described in more detail below with reference to preferred embodiments. In response to the above-mentioned prior art, the present inventors conducted extensive research into the breeding and release of natural enemy insects in commercially available breeding devices for natural enemy insects, leading to the present invention. The present inventors conducted extensive research into the breeding conditions of natural enemy insects in commercially available breeding devices for natural enemy insects and the number of natural enemy insects released from the devices. As a result, they found that, for example, when Phytoseiulus swirskii is used as the natural enemy insect, the number of natural enemy insects released from the device tends not to be maintained as sufficiently over a long period of time as expected, making it difficult to say that the effects of using the breeding device for natural enemy insects are consistently and sufficiently achieved. In light of this situation, the present inventors felt that, since the use of Phytoseiulus swirskii mites has already been put to practical use and is being used, it was urgent to improve this point. Focusing particularly on this point, the present inventors conducted extensive research and arrived at the present invention.

[0022] According to the present invention, it is possible to significantly improve the proliferation of one species of phytoseiid mite contained in a pack formulation by simple means, compared to conventional natural enemy insect propagation devices. Moreover, surprisingly, according to a preferred embodiment of the present invention, the improved proliferation state can be maintained for a longer period of time, and the number of natural enemy insects released from the propagation device can be improved so that it is sufficient for a long period of time. Therefore, according to a preferred embodiment of the present invention, the effect of increasing the number of natural enemy insects released is more sustained by the improved natural enemy insect propagation device, which reduces the number of times the device needs to be replaced, thereby achieving the excellent effects of reducing running costs and the labor required for farmers to install the device.

[0023] Furthermore, during the above-mentioned investigations, the inventors also noted that conventional natural enemy insect breeding devices and pack formulations all utilize a single specific type of natural enemy insect that feeds on a specific target pest insect and release it within a facility to control the pest, and that the same device or pack formulation does not consider using multiple types of natural enemy insects and breeding each of them for pest control. This is thought to be due to the following reasons. The important thing about natural enemy insect breeding devices and pack formulations is to stably breed specific natural enemy insects using bait mites, maintain stable habitat conditions, release the breeding natural enemy insects within a facility, and control the pests by having the specific natural enemy insects prey on specific pest insects as food. However, allowing multiple types of natural enemy insects to coexist within the same device would destabilize the breeding and habitat conditions of each natural enemy insect, so it was commonly believed to be difficult to release multiple types of natural enemy insects from the same device in conditions favorable for pest control.

[0024] In response to this situation, the present inventors thought that if it were possible to breed multiple types of natural enemy insects in a single breeding device and use the device for IPM (integrated pest management), the breeding device would be extremely useful. The present inventors then conducted extensive research on this point and found that by improving the breeding device for natural enemy insects when phytoseiid mites are used as the natural enemy insects discussed above, it is possible to breed phytoseiid mites stably for a long period of time in the same breeding device, and also to breed Gammaria mites, another natural enemy insect, in the same breeding device. These released natural enemy insects prey on the pest insects that they feed on, thereby enabling the control of multiple types of pest insects. This resulted in the development of a breeding device for natural enemy insects that provides a completely new effect not previously seen. With this new breeding device for natural enemy insects, the released natural enemy insects, phytoseiid mites, control pests on "above-ground parts such as leaves, flowers, buds, stems, and branches," while another natural enemy insect, Gamasid mites, control pests on "underground parts such as the soil edge and roots." This makes it possible to control pests over a wide area with natural enemy insects using a single breeding device, something that could never be achieved with conventional natural enemy insect breeding devices or pack formulations.

[0025] The present invention was arrived at as a result of detailed studies on the case where the natural enemy insect contained in the pack formulation of a natural enemy insect propagation device (natural enemy support material) is Phytoseiulus californicus (aka Phytoseiulus californicus). However, the present invention is a technology that can be similarly applied to other phytoseiid mites. The inventors conducted a comparative study on the case where Phytoseiulus californicus, a natural enemy insect used in a commercial natural enemy insect propagation device, was used as a pack formulation as is and the case where the pack formulation was contained in a natural enemy insect propagation device (natural enemy support material). As a result, when Phytoseiulus californicus was used as the natural enemy insect, as described above, there was a tendency for there to be no significant difference in the number of insects released, etc., between the use of the pack formulation as is and the use of a natural enemy insect propagation device (natural enemy support material) containing the pack formulation in a conventional manner. However, when Phytoseiulus californicus was used as the natural enemy insect, the use of a natural enemy insect propagation device containing Phytoseiulus californicus (aka Phytoseiulus californicus) produced significantly better results than the use of the pack formulation as is.

[0026] That is, when Phytoseiulus californiae was used as the natural enemy insect, the use of a natural enemy insect breeding device (natural enemy support material) was confirmed to be more effective than when using a pack formulation as is, as it consistently achieved effects such as an increase in the number of natural enemy insects released. However, even when Phytoseiulus californiae was used as the natural enemy insect, it was desired to further increase the number of natural enemy insects released and to achieve a longer release period with one natural enemy support material, just as in the case of Phytoseiulus swirskii discussed above.

[0027] In contrast, it has been recognized that by improving the breeding device for natural enemy insects by simple means, as in the configuration specified in the present invention, it is possible to improve the release state of Phytoseiulus californiae, a natural enemy insect belonging to the phytoseiid mite genus, compared to when conventional devices are used, just as in the case of Phytoseiulus swirskii. Furthermore, in a technology specified in the present invention, which the present inventors have studied in detail and found to be effective, in which two types of natural enemy insects, namely phytoseiid mites such as Phytoseiulus swirskii, which can control pests above ground, and Gambusia nigricans, another natural enemy insect that controls pests underground and cannot be controlled by phytoseiid mites, are breeding together in the same device and these two different types of mites are effectively used to control pests, Phytoseiulus californiae, a phytoseiid mite, can be used in the same way as Phytoseiulus swirskii.

[0028] The first object of the present invention is to provide an effective breeding device (natural enemy support material) for natural enemy insects, which can increase the number of phytoseiid mites released by breeding them in larger numbers, a type of natural enemy insect that has traditionally been used to control above-ground pest insects. The second object of the present invention is to provide a natural enemy support material that can sustainably release larger numbers of phytoseiid mites over a longer period of time. As will be described later, the improvements made in the present invention involve various improvements to the individual habitats and egg-laying environments of phytoseiid mites and their prey mites. Specifically, first, sugars, which serve as food for phytoseiid mites, are provided in a suitable condition that contributes to their proliferation. Additional measures, such as devising the prey mites to maintain proliferation over a long period of time and maintaining high humidity within the device, are also implemented. Because all of these improvements relate to habitat conditions that are considered to be common to phytoseiid mites, it is normal for similar effects to be obtained even when different types of phytoseiid mites are used. Furthermore, even when the third object of the present invention is to combine phytoseiid mites, which control pests above ground, with Gamagoma mites, another natural enemy insect that controls pests below ground, and to use each natural enemy insect to control completely different pests, the habitat and egg-laying environment of the phytoseiid mites and Gamagoma mites are improved to allow the stable proliferation of both, and it can be said that it is normal for similar trends to be shown and similar effects to be obtained even if the types of these mites are changed.

[0029] In the present specification, when explaining the present invention, Phytoseiulus swirskii is described as a representative example of phytoseiid mites, which are natural enemy insects. This is because, as mentioned above, the effectiveness of using a breeding device for natural enemy insects (natural enemy support material), which is thought to function as a shelter for natural enemy insects, is inferior to that of using Phytoseiulus californicus as a natural enemy insect, particularly in the case of Phytoseiulus swirskii, compared to when using Phytoseiulus californicus as a natural enemy insect. Therefore, if this can be improved, the present invention can achieve even greater effectiveness. As described above, the technology of the present invention is applicable to phytoseiid mites used as natural enemy insects when controlling above-ground pest insects. Furthermore, another technology of the present invention makes it possible to breed two types of natural enemy insects in the same device, and in this case, the effectiveness of combining phytoseiid mites, which control above-ground pest insects, with Gambusia mites, which control underground pest insects, such as at the soil line, has been discovered. By utilizing this different technology, it will be possible to control pests underground, such as at the soil line, in addition to the conventional method of controlling pests above ground using the same propagation device, which will hopefully enable pest control over a wide area using natural enemy insects.

[0030] The background to the present invention is explained below. First, the use of conventional natural enemy support materials in Japan and around the world is described. When the bottle formulations, pack formulations, and bunker sheets used in the aforementioned conventional technologies are used on greenhouse crops, they function as outlined below, resulting in significantly different natural enemy insect propagation efficiencies. When using bottle formulations, natural enemy insects contained in the bottles are released directly onto the crops together with bran (carrier). As a result, the propagation efficiency of natural enemy insects within the formulations is low. Pack formulations are small pouch-shaped materials containing natural enemy insects, one type of prey mite, such as sugar mite, and bran or other food for the prey mite, and this material is placed on the crops. In the case of pack formulations, the natural enemy insects that multiply by preying on the prey mites within the material are gradually released onto the crops. Therefore, compared to bottle formulations, a greater number of natural enemy insects are released, and the release period is longer (up to several weeks).

[0031] Bunker Sheet (registered trademark) is a natural enemy support material made of waterproof paper, and is more water-resistant and durable than pack formulations. As explained above, there are various types, including a pack formulation and a felt oviposition substrate placed in an enclosed space inside the material, and a type that contains a water-retaining material for regulating humidity within the space as needed, and these are placed on crop branches and the like. Bunker Sheets are considered to be particularly effective as shelters that protect natural enemy insects from environmental changes such as temperature and humidity, and it is expected that the period during which natural enemy insects are released will be longer when the bunker sheet contains a pack formulation in a container than when the bunker sheet contains only a pack formulation.

[0032] In contrast, the inventors' studies surprisingly found that when using bunker sheets with Phytoseiulus swirskii as a natural enemy insect, the number of natural enemy insects released was not significantly different from when only the pack formulation was used. Furthermore, detailed studies by the inventors revealed that this tendency was particularly pronounced when the relative humidity of the installation environment was high. That is, when the relative humidity of the installation environment was low, the number of natural enemy insects released was higher when using bunker sheets than when only the pack formulation was used. Furthermore, in the studies in which the number of natural enemy insects released was not significantly different from when only the pack formulation was used, as is commonly done, bunker sheets were used that contained 2-3 g of a water-retaining material, which is an accessory for commercially available bunker sheets. Based on these findings, the inventors found that if the relative humidity of the installation environment can be stably maintained at a high value, for example, 90% or higher, it is possible to increase the number of natural enemy insects released even with only the pack formulation. However, maintaining the relative humidity of the installation environment, such as the interior of a greenhouse, at a constant 90% or higher is difficult in terms of running costs. Therefore, the inventor first came to the conclusion that when using a bunker sheet, it is necessary to increase the humidity inside the bunker sheet. Further research was conducted based on the recognition that in order to achieve the effect of further increasing the number of natural enemy insects released, it is necessary to not only increase the moisture content of the water-retaining material, but also to devise a way to achieve a greater effect.

[0033] The present inventors also conducted research into achieving a new effect that was completely unimaginable in conventional bunker sheet application techniques, namely, breeding two types of natural enemy insects in the same device and releasing them for use in IPM. According to the inventors' research, in all of the previously known bottle formulations, pack formulations, and bunker sheets, the natural enemy insect used is one type of phytoseiid mite selected from polyphagous phytoseiid mites, such as Phytoseiulus californicus, Phytoseiulus swirskii, and Phytoseiulus cucumeris, depending on the type of pest to be controlled. Furthermore, while bottle formulations are known as examples of using Gamas mites as natural enemies, there are no known examples of using Gamas mites as natural enemies in pack formulations or bunker sheets. Furthermore, according to the inventors' research, in all of the bottle formulations, pack formulations, and bunker sheets, there are no known examples of using multiple types of natural enemy insects housed in the same material, which is the objective of the present invention and the invention.

[0034] However, bottled and packaged formulations are susceptible to environmental changes such as temperature and humidity, and a major problem is that their effectiveness is not stable under greenhouse cultivation conditions in Japan. Meanwhile, according to the inventor's research, although bunker sheets are excellent in protecting natural enemy insects (effective as a shelter), there remains a problem with the reproduction efficiency of natural enemy insects, and this is thought to be a practical issue when widely deploying them in greenhouse horticultural crops (vegetables, fruit trees, flowers, etc.). As mentioned above, according to the inventor's research, for example, when bunker sheets using Phytoseiulus swirskii as a natural enemy insect are used, depending on environmental conditions such as temperature and humidity, the phytoseiulus swirskii mites do not multiply significantly, and a significant improvement in reproduction effect cannot be obtained by storing a packaged formulation in the bunker sheet.

[0035] As explained above, bunker sheets incorporate a pack formulation, a water-retaining material (such as a water-absorbent polymer that retains water) for the purpose of promoting the proliferation of natural enemy insects, and felt as an egg-laying site. However, according to the inventor's investigations, even with bunker sheets that meet these requirements, no dramatic improvements were observed in the number of Phytoseiulus swirskii mites released or the release period, particularly in cases where Phytoseiulus swirskii mites were used as natural enemy insects. For this reason, the inventor recognized that an important technical challenge is to further introduce some new technology into bunker sheets that already use Phytoseiulus swirskii mites as natural enemy insects, thereby improving the number and release period of Phytoseiulus swirskii mites, and that solving this problem is urgently needed to promote the spread of IPM (integrated pest management).

[0036] As mentioned above, conventional pack formulations and bunker sheets using pack formulations contain only one type of natural enemy insect selected from phytoseiid mites in one pack formulation. However, there are multiple types of micro-pests that attack greenhouse horticultural crops, and the optimal natural enemy insect for each micro-pest is often different. Therefore, to control multiple types of micro-pests within a greenhouse, it is necessary to use multiple pack formulations. This poses a major problem for practical application: pest control techniques using pack formulations are expensive compared to chemical pesticides that are effective against multiple types of micro-pests with a single formulation.

[0037] As a result of extensive research into the above situation, the present inventors have found that the following are important in order to increase the breeding efficiency of natural enemy insects in bunker sheets and to improve the number and duration of release of natural enemy insects. First, as described in Patent Document 2 cited above, it is said that this can be achieved by applying a moisture-sustaining material with sustained moisture release, and an effective means is to "create high humidity conditions (70% RH or higher) suitable for the breeding of natural enemy insects and feeding mites, and stably maintain this condition for a long period of time" within the space of the bunker sheet.

[0038] However, the inventors' investigations have revealed that, as mentioned above, the water content achieved by the water-retaining materials included with commercially available bunker sheets is insufficient to achieve the objectives of the present invention. Specifically, the inventors have discovered that in order to improve the number and duration of release of natural enemy insects, it is effective to incorporate a water-retaining material with a higher water content within the bunker sheet. Furthermore, as a result of further investigations, the inventors have found that, for example, even if the water-retaining material were made more functional and the water content of the water-retaining material incorporated within the bunker sheet were reliably increased compared to conventional methods, the effect would be improved compared to conventional methods, but would not result in a dramatic improvement in the number and duration of release of natural enemy insects.

[0039] In response to this situation, the present inventors conducted extensive research into improving bunker sheets that use Phytoseiulus swirskii as a natural enemy insect, a representative example of phytoseiid mites, and as a result, arrived at the present invention. Specifically, the present inventors concluded that in order to achieve the first object of the present invention, in addition to "maintaining high humidity conditions (70% RH or higher) within the space of the bunker sheet for an extended period of time" using a water-retaining material made of a moisture-sustaining material with sustained moisture release, as has been done conventionally, it would be highly effective to require that the water-retaining material "contain bait that has been moistened with an aqueous solution containing sugars."

[0040] As mentioned above, it is already known that "maintaining the space of the bunker sheet at high humidity (70% RH or higher) for a long period of time" is effective in preventing the habitation of phytoseiid mites. For this purpose, a water-retaining material such as a superabsorbent resin is used, and the water-retaining material is placed inside the bunker sheet, retaining water in the space. This configuration is said to achieve "maintaining the space of the bunker sheet at high humidity (70% RH or higher) for a long period of time." The inventors conducted detailed studies on this point. As a result, they first confirmed that the use of the water-retaining material used in the embodied product resulted in an increase in the total number of natural enemy insects released and a longer release period compared to when no water-retaining material was used.

[0041] In this case, for example, by using a highly water-absorbent resin with a higher water-retention capacity to store water-retention materials in the bunker sheet instead of conventional products on the market, the inventors have found that this can achieve a longer release period for natural enemy insects compared to conventional devices. Specifically, the space inside the bunker sheet is narrow and can accommodate approximately five water-retention materials. However, the water-retention materials used in conventional products (0.5 g / 5 pieces) retain 2-3 g of water when fully loaded. In contrast, if a more water-absorbent material is used, the five pieces retain 4-7 g of water when fully loaded, achieving a higher water content than conventional products. Furthermore, according to the inventors' research, simply using such water-retention materials with a higher water content, retaining 4-7 g of water per five pieces, more preferably 5-7 g of water, can achieve a longer release period compared to conventional water-retention materials. Specific examples of this point will be described later. Increasing the amount of water retention using water-retaining materials used in conventional golf balls can be achieved by increasing the number of water-retaining materials used. However, this requires increasing the space inside the bunker sheet, which requires changing the shape of the bunker sheet to make it larger.

[0042] After further investigation, the inventors discovered that "introducing artificial bait into the bunker sheet that can be utilized by natural enemy insects and prey mites" is effective and highly effective. Furthermore, this can be easily achieved by effectively utilizing the water-retaining material described above to "contain bait retained in a sugar-containing aqueous solution," and that this configuration produces significant benefits. Specifically, the inventors discovered that sugars are the optimal artificial bait, and that the objective of the present invention can be achieved by incorporating this in a sugar-containing aqueous solution, thereby retaining the water in the bunker sheet. Sugars readily dissolve in water to form an aqueous solution, and can also be used to retain the water in the moisture-sustaining moisture-retaining material described above, which "maintains high humidity conditions (70% RH or higher) for an extended period of time within the bunker sheet." The inventors' investigations revealed that the sugars placed in the bunker sheet by the above-described simple method are utilized as bait for the natural enemy insects and prey mites living within the bunker sheet, thereby promoting their continued proliferation, thereby effectively achieving the objective of the present invention. Examples of sugars that constitute the present invention include trehalose, honey, brown sugar, molasses, glucose, fructose, sucrose, sorbitol, and erythritol, and any of these can be used, and the effects of the present invention can be obtained by using these as feed.

[0043] Although details will be provided later, a more preferred embodiment of the present invention involves using monosaccharides, disaccharides, or sugar alcohols among sugars as the "artificial bait available to natural enemy insects and bait mites within the bunker sheet," or using a substance containing a nitrogen component in addition to the sugar. According to the inventor's research, by using monosaccharides or a substance containing a nitrogen component in addition to the sugar, it is possible to increase the number of natural enemy insects released from the bunker sheet without increasing the sugar concentration, and to extend the release period of the natural enemy insects. The nitrogen component of the above-mentioned substance can be either the nitrogen component in organic matter or the inorganic component in inorganic compounds.

[0044] Examples of nitrogen-containing substances used in the present invention include peptone, yeast, urea, amino acids, and vitamins. As with sugars, these substances can be easily placed in the bunker sheet by dissolving them in the aqueous solution used to maintain a moisture-retaining, sustained-release moisture-retaining material for maintaining high humidity conditions within the bunker sheet. This provides effective bait for natural insect enemies and prey mites. Other substances, such as aqueous solutions containing minerals, may also be used. The yeast referred to above is a "microorganism, i.e., a bacterium, that breaks down sugars into alcohol and carbon dioxide (performs alcoholic fermentation) and is used to ferment foods and alcoholic beverages." Any yeast used in fermented foods can be used. Specific examples of yeast that can be used in the present invention include beer yeast, wine yeast, baker's yeast (yeast, natural yeast), and miso yeast. The yeast referred to above is basically a single type of yeast specifically for bread, cultivated by cultivating it, while natural yeast is a yeast cultivated from natural sources such as grains and fruits.

[0045] Furthermore, as a result of intensive research, the inventors have discovered that, in addition to the above-mentioned conditions, by adopting a "new configuration in which a different species of prey mite that can utilize the newly introduced artificial bait is introduced, and multiple species of prey mites are used in combination," it is possible to stably maintain a large number of prey mites for natural enemy insects contained within the bunker sheet for a longer period of time than with currently used commercially available bunker sheets. In other words, in order to achieve the first object of the present invention at a higher level, in addition to making the water-retaining material "containing bait that is moistened with an aqueous solution containing sugars," it is effective to use multiple species of prey mites for natural enemy insects in the bunker sheet, whereas in conventional technology only one type of mites were used, and they have recognized that by configuring it in this way, it is possible to obtain the above-mentioned effect at a higher level and in a more stable manner.

[0046] Based on the above understanding, the present inventors conducted the following study to find the feasibility and advantages of replacing the single type of bait mite housed in the bunker sheet with a configuration using multiple types of natural enemy insects. Specifically, the inventors studied the use of two types of bait mites, T. sugari and T. sieboldii, as a representative example, and the conditions for doing so. Commercially available bunker sheets use either T. sugari or T. sieboldii as the bait mite, and when the natural enemy insect is Phytoseiulus swirskii, T. sugari is used as the bait mite. T. sugari belongs to the family Acaridae, and T. sieboldii belongs to the family Sarcoideae, both of which are classified in the suborder Acaridae. The mites of the Acaridae family used as bait mites in addition to T. sugari used in the above study are also mites classified in the suborder Acaridae, such as T. putrefactive mites.

[0047] The present inventors conducted various laboratory evaluation tests using Phytoseiulus swirskii and obtained the above findings, which led to the present invention. First, they found that a new composition using a slow-release water-retaining material containing a bait-containing water-retaining material that was moistened with an aqueous solution containing sugars dramatically improved the number and duration of release of the natural enemy insect Phytoseiulus swirskii. Specifically, the use of a bait-containing water-retaining material alone achieved a revolutionary effect on the proliferation of natural enemy insects compared to the use of conventional water-retaining materials containing water. The present inventors found that adding the following innovation to the effective "water-retaining material containing bait" for the prey mites of natural enemy insects would be even more effective. Specifically, currently used pack formulations using Phytoseiulus swirskii contain one species of sugar mite as a prey mite for Phytoseiulus swirskii. However, they found that using a grain mite in addition to the sugar mite as a prey mite would provide even greater effectiveness. Furthermore, in this case, it is preferable to configure the initial density of sugar mite to be greater than that of grain mite. Specifically, a more stable effect can be obtained by setting the initial density of bait mites at, for example, 500 to 1500 sugar mites and 2 to 40 astigmatids. For example, it is more preferable to set the initial density of sugar mites at about 1000 and the initial density of astigmatids at about 5 to 20. The effects of the present invention will be explained below by giving an outline of a study example.

[0048] The present inventors have discovered that by improving the bunker sheet to have the configuration specified in the present invention, the number and duration of release of natural enemy insects from the bunker sheet can be increased by approximately 1.5 to 2 times compared to when conventional bunker sheets are used, resulting in dramatic improvements. First, a configuration in which the bait mites of natural enemy insects in the bunker sheet are a combination of sugar mites and astigmatids, instead of only sugar mites as in conventional products, will be described. According to the inventors' studies, when a bunker sheet containing two types of bait mites, sugar mites and astigmatids, was used, and tests were conducted under temperature and humidity conditions of, for example, 25°C and 75% RH, the Swirlskii mites in the pack formulation first preyed on the sugar mites, which were in greater numbers, and multiplied for 1 to 3 weeks after installation, then preyed on sugar mites and astigmatids for the next 4 to 5 weeks, and then preyed on mainly astigmatids for the next 6 weeks. In contrast, when a bunker sheet using a conventional pack formulation containing only C. sugarcane mites as bait mites was used, and confirmation was conducted under temperature and humidity conditions of 25°C and 75% RH, it was found that the food supply became insufficient and the proliferation of Phytoseiulus swirskii ceased in about 4 to 5 weeks.In contrast, as will be described in detail below, the proliferation of Phytoseiulus swirskii in a bunker sheet containing both C. sugarcane mites and Acaridae as bait mites continues for a significantly longer period of time than the proliferation of Phytoseiulus swirskii in a conventional bunker sheet.

[0049] The inventors conducted studies using the bunker sheet of the present invention, which is configured to use the bait-containing water-retaining material described above and the two types of prey mites described above, and confirmed that Phytoseiulus swirskii can continue to multiply for up to approximately 13 weeks. Detailed studies have shown that, although the number of grain mites newly contained as prey mites other than sugar mites in a pack formulation of the bunker sheet of the preferred configuration of the present invention is smaller than that of sugar mites at first, they are omnivorous and multiply in large numbers by feeding not only on the food for the prey mites, such as bran, in the pack formulation, but also on a variety of other materials, such as the excrement, carcasses, and mold of prey mites and natural enemy insects. Meanwhile, the multiplication of sugar mites, which were used as prey mites for Phytoseiulus swirskii in the prior art, gradually weakens and is replaced by grain mites after four weeks from the initial stage. Thereafter, the acarid mites continued to multiply for about 13 weeks by using the water-retaining material containing bait as described above, and functioned as food mites for the Swirlskii mite, and as a result, it was found that the proliferation of the Swirlskii mite was maintained.

[0050] Furthermore, the present inventors have found that by using a bunker sheet with a more preferred configuration of the present invention, the number of Phytoseiulus Swirskii mites released from the bunker sheet can be increased, and the release of Phytoseiulus Swirskii mites can be maintained for a longer period of time. Specifically, in a bunker sheet with a more preferred configuration of the present invention, in addition to the pack preparation with the above-mentioned devised bait mite configuration, a felt member for egg-laying and a water-retaining material consisting of a moisture-sustaining material are arranged, and as mentioned above, the water-retaining material is a water-retaining material containing bait that has been moistened with an aqueous solution containing sugars. By providing the bunker sheet with the above-mentioned new more preferred configuration, the present invention can achieve the following remarkable effects.

[0051] As described above, the Swirskii mites and prey mites that have continued to multiply in large numbers within the pack move from the pack to the interior of the main body of the bunker sheet. As described above, the main body contains a water-retaining material containing bait, which is maintained with a sugar-containing aqueous solution. Therefore, the Swirskii mites and prey mites feed on the sugars contained in the water-retaining material and further multiply within the main body of the bunker sheet. The felt egg-laying members located in the main body of the bunker sheet are effectively utilized for multiplication. By using a pack containing two types of prey mites, the effect of multiplying natural enemy insects can be maintained for a longer period of time than when using a conventional pack containing a single type of prey mite. The Swirskii mites that have multiplied in this way are released into a facility such as a greenhouse through an accessible gap in the enclosed space of the main body of the bunker sheet, where they live, feeding on pests such as thrips and whiteflies that are attached to plants. In this case, as described above, the Swirlskii mites continue to multiply within the bunker sheet for a long period of time, and it becomes possible to release a large number of natural enemy insects from the bunker sheet into the facility for a long period of time. As a result, the technology of the present invention makes it possible to effectively control pests using natural enemy insects for a long period of time.

[0052] As mentioned above, the present inventors have recognized that it would be extremely useful to develop an all-in-one bunker sheet that can be used to control different pests over a wider area, both above and below ground, using the same device, something that was completely unthinkable with conventional bunker sheets. After extensive research into this point, the inventors have found that, in addition to the improvements made to conventional bunker sheets, as described in the preferred configuration above, that is, "an aqueous solution containing sugars and, if necessary, a nitrogen component is retained in a water-retaining material as artificial bait" and "the conventionally used sugar mites are used as bait mites, but with the addition of a grain mite at an initial number lower than that of the sugar mites," it is possible to effectively use two types of natural enemy insects to control pests with a single bunker sheet by adding Gamas mites to one type of phytoseiid mite that has been conventionally used as natural enemy insects, for example, at an initial density of Gamas mites for every 100 phytoseiid mites of the same type. Here, Phytoseiulus swirskii and Phytoseiulus californiae are classified in the Phytoseiidae family, and Gamasidae are classified in the Gamasidae family, but they are all classified in the order Acari and the suborder Gamasida. The following describes the breeding device for natural enemy insects of the present invention, which corresponds to the third object of the present invention.

[0053] More specifically, in the breeding device for natural enemy insects of the present invention, which corresponds to the third object, for example, when the initial density of Phytoseiulus swirskii is about 200 to 300 individuals, by setting the initial density of Gamas mites to about 2 to 8 individuals, it is possible to achieve the effects of the present invention that could not be achieved by conventional techniques. According to the inventor's studies, if the number of Gamas mites is increased from the beginning to increase the density, the Gamas mites will prey on many prey mites, hindering the proliferation of Phytoseiulus swirskii. Furthermore, this is undesirable because the Gamas mites themselves will be eaten. In contrast, if Gamas mites are initially present in small numbers as described above, the Phytoseiulus swirskii mites will first prey on prey mites such as sugar mites and multiply. Then, when the proliferation of Phytoseiulus swirskii mites has settled down, the Gamas mites, which have gradually multiplied from a small number, can prey on prey mites such as astigmatids and multiply explosively. As a result, it was confirmed that after the release of the Swirlskii mites, the Gambusia mites were released outside five weeks after the installation of the bunker sheets inside the facility, and they preyed on the pests that the Gambusia mites preferred, thereby enabling the control of other pests.

[0054] Furthermore, in the specification of the present application, as will be described later, when explaining the configuration and effects of the present invention, Hypoaspis sp., a type of natural enemy insect of the Gamagomatidae family, is described as a representative example of Gamagomatidae, which are natural enemy insects. Furthermore, although further studies, such as confirmation tests of the degree of effect obtained, are desired for practical application, the present inventors have recognized that when a type of natural enemy insect of the Macrochelidae family (Stratiolaelaps sp.), which belongs to the Gamagomatidae suborder and has an ecology similar to that of Hypoaspis sp., is used in combination with Phytoseiulus swirskii, both natural enemies can multiply. The fact that both of the two types of natural enemies combined above can be propagated can be understood from the fact that bottle formulations of Hypoaspis genus H. miles and Stratiolaelaps genus S. scimitus are known overseas as examples of using astagomites as natural enemy insects, and that in Japan, although not yet formulated, it is known that indigenous natural enemies such as H. yamauchii can be propagated using astagomites and used for pest control. Thus, the technology of the present invention can be applied to various astagomites of the suborder Astagomi, which propagate by feeding on astagomites and are capable of preying on underground pests, and can also be used with natural enemy insects of the family Macrocaridae (e.g., Stratiolaelaps) and the family Ascidae (e.g., Ascidae), as in the case of Hypoaspis sp., which is described as a representative example in the specification of this application.

[0055] In other words, with the above-mentioned configuration, both Phytoseiulus swirskii and Gamas mites can be propagated at appropriate times in a single bunker sheet, and these two types of natural enemy insects can be released into a facility from the bunker sheet, allowing each to be used to control a different pest. Specifically, this invention makes it possible to simultaneously control thrips, etc., that damage leaves and flowers, with Phytoseiulus swirskii, and fungus gnats, etc., that damage roots and soil-level areas, with Gamas mites, all in a single bunker sheet. Thus, according to a preferred embodiment of the present invention, Phytoseiulus swirskii can be first propagated over a long period of time in a single bunker sheet, and then, after the proliferation of Phytoseiulus swirskii has declined, the proliferation of Gamas mites can be activated.

[0056] In order to achieve the above-mentioned effects of the present invention, the configuration of a breeding device for natural enemy insects (natural enemy support material) is specified as follows. First, the basic configuration is such that, inside a main body having an enclosed space through which the natural enemy insects can enter and exit, at least natural enemy insects, prey mites that serve as food for the natural enemy insects, small pouch-shaped members containing at least food for the prey mites, a felt member for egg-laying, and a moisture-retaining material consisting of a moisture-slow-releasing water-retaining material are placed. An example of a product with this basic configuration is the Bunker Sheet (registered trademark) described above.

[0057] In a first aspect of the present invention, the pouch-shaped member (pack preparation) is characterized in that the natural enemy insect is one type of phytoseiid mite, a representative example of which is Phytoseiulus swirskii, and the bait mite that serves as food for the natural enemy insect is at least one type of sugar mite of the family Caryopsis, a member of the suborder Acaridae, a representative example of which is Caryopsis sugar mite, and in particular, the water-retaining material contains bait that has been moistened with an aqueous solution containing sugars. This configuration improves the proliferation of phytoseiid mites, a natural enemy insect, that inhabit the pouch-shaped member and the main body of the natural enemy insect propagation device, compared to conventional bunker sheets, and as a result, the amount of natural enemy insects for phytoseiid mites released from the propagation device can be increased.

[0058] In a second aspect of the present invention, the bait mite configuration described above is further characterized in that, in addition to the sugar mite, one type of acarid mite of the Astigmatidae family, represented by Astigmatism, is included, and the initial density of the acarid mite is set to be lower than that of the sugar mite. This configuration allows the proliferation of phytoseiid mites, which are natural enemy insects, that live within the pouch-shaped member and the main body of the natural enemy insect breeding device to continue for a longer period of time than with conventional bunker sheets, thereby further improving proliferation, and as a result, the release of natural enemy insects from the natural enemy insect breeding device can be maintained in good condition for a long period of time.

[0059] Furthermore, a third invention for achieving the third object of the present invention is characterized in that it uses two different types of natural enemy insects. Specifically, in the third invention, in the first or second invention described above, the natural enemy insects further include Gamas mites as natural enemy insects, and an essential requirement is that the initial density of the Gamas mites is 1 to 3 per 100 of the one type of phytoseiid mites. As will be described later, this configuration allows the Gamas mites to multiply after the proliferation of the phytoseiid mites has stabilized after a good proliferation of the natural enemy mites. This makes it possible to release different types of natural enemy insects from a single natural enemy insect propagation device, thereby enabling the control of multiple types of pest insects within a facility. Until now, there has been no idea behind the third invention mentioned above, which is to efficiently multiply multiple species of natural enemy insects with different ecologies such as feeding habits and habitats in, for example, a single pack formulation, thereby enabling the multiplied natural enemy insects to settle in various locations on crops, particularly above-ground parts such as leaves, flowers, and stems, as well as underground parts such as the soil and roots, thereby protecting the entire crop from microscopic pests with the natural enemy insects. Of course, there is no technology or natural enemy insect multiplication device that can achieve this. [Example]

[0060] The device for protecting natural enemy insects of the present invention will be described in more detail below using examples, but the present invention is not limited to the following examples in any way.

[0061] (Test Method) Various studies were carried out using the Swirl Bunker (registered trademark, manufactured by Ishihara Biosciences), a commercially available natural enemy support material (protection device for natural enemy insects) that is configured so that workers assemble each component into a usable configuration when installing it on plants, etc. within a facility. Specifically, a waterproof paper assembly container from the components (accessories) of the commercially available product was used for the main body of the natural enemy insect protection device, and black felt from the commercially available components was used as the felt component for egg-laying.

[0062] The pack formulation used contained 250 Swirlskii mites per pack, which is a component of the above-mentioned commercially available product. In the examples of the present invention, the bait mites were improved in this commercially available pack formulation, and Hypoaspis sp., a type of Gamagridae mite, was added as another natural enemy insect to conduct studies using each of these. Specific methods will be described later.

[0063] The water-retaining materials used were the same superabsorbent polymer as the component of the commercially available natural enemy support material (Swirl Bunker) described above, and a granular superabsorbent polymer with higher water absorption than that used in the commercially available natural enemy support material. Specifically, the superabsorbent polymer used in the commercially available product weighs approximately 0.05 g per 5 pieces, which weighs 2–3 g per 5 pieces when hydrated. In the following tests, as described below, we primarily used a granular superabsorbent polymer with higher water absorption, which weighs 5–7 g per 5 pieces when hydrated, and which resulted in a longer-lasting increase in the release of natural enemy insects. In the examples of the present invention, five pieces of water-retaining material with higher water absorption were used, each of which was hydrated with aqueous solutions containing various sugars, etc. The hydrated water-retaining materials were then placed inside the main body and tested at 25°C and 75% RH. Furthermore, the five water-retaining materials placed inside the main body of the natural enemy support material were each placed so that the total weight after water retention was constant, and the test conditions were standardized. When commercially available natural enemy support material is actually used to release natural enemy insects, the granular superabsorbent polymer that is a component of the product is used as the water-retaining material by retaining it with water, but in this case, tap water is considered acceptable. In contrast, in the tests described below, distilled water was used as the aqueous solution used for hydration, taking into consideration the effect on mites of trace components contained in tap water. Hereinafter, this will sometimes be simply referred to as water.

[0064] The effectiveness of each natural enemy support material was confirmed using the following procedure. Each natural enemy support material was placed in a container with the humidity adjusted to 75% RH at 25°C. Every week, the support material was removed and the container was replaced, and the number of natural enemies remaining in the container after replacement was counted. Each natural enemy support material was investigated in this manner until no more natural enemy insects were released from the natural enemy support material.

[0065] (Confirmation test on the effectiveness of using water-retaining materials) We used a water-retaining material (granular superabsorbent polymer) intended to increase the humidity inside the main body of the commercially available natural enemy support material mentioned above to confirm the effect of installing the water-retaining material on the release of natural enemy insects. First, when natural enemy support material without the water-retaining material was used, the trend toward increasing the number of natural enemy insects released stopped after about 4 to 5 weeks, depending on the installation environment. For example, when the relative humidity of the installation environment was set to 75% RH. This shows that without the use of a water-retaining material, under normal environmental conditions, the release of new natural enemy insects from the natural enemy support material stops after about 4 to 5 weeks.

[0066] Therefore, we placed natural enemy support materials in containers regulated at 25°C and 75% RH, and investigated whether the release of the natural enemy insect, Phytoseiulus swirskii, would differ when two types of water-retaining materials with different water contents were used. Specifically, we used natural enemy support materials that were hydrated with distilled water and contained two types of water-retaining materials: one with a low water content (five pieces weighing 2g-3g in total) and one with a high water content (five pieces weighing 5g-7g in total). Each type was placed in a container regulated at 25°C and 75% RH for testing. We then replaced the containers for each natural enemy support material every week, counting the number of natural enemies remaining in each container after replacement, and confirmed the release of natural enemy insects.

[0067] As mentioned above, it is known that using natural enemy support materials containing water-retaining materials can prolong the period during which the number of natural enemy insects released increases compared to when no water-retaining materials are used. In contrast, tests conducted by varying the water content of the water-retaining materials revealed that the degree to which the period during which the number of natural enemy insects released increases differs depending on the water content of the material. Specifically, when five water-retaining materials with a total weight of 2g to 3g were placed, the trend toward an increase in the number of natural enemy insects released stopped after four to five weeks, whereas when five water-retaining materials with a total weight of 5g to 7g were placed, the trend toward an increase in the number of natural enemy insects released was prolonged, with proliferation continuing for up to eight weeks, after which the trend toward an increase in the number of natural enemy insects released stopped. The above results show that, compared to using water-retaining material contained as a component of commercially available natural enemy support materials, which are wetted before use and have a total weight of 2g to 3g for five pieces when wet, simply using a highly water-absorbent resin water-retaining material with a total weight of 5g to 7g for five pieces when wet can extend the release period by approximately 3 to 4 weeks compared to conventional materials.

[0068] (Tests on the improvement of bait mites and water-retaining materials) To achieve the object of the present invention of increasing the release of phytoseiid mites at a higher level, we investigated the improvement of the bait mites contained in commercially available pack formulations for natural enemy insects. Specifically, we added acarid mites to sugar mites, which have traditionally been used in pack formulations, and conducted a test to confirm the effect achieved by using these mites in combination as bait mites. Furthermore, the inventors conducted the following test to solve the problem of a shortage of bait materials for natural enemy mites and bait mites, which is a concern due to the change in the composition of the bait mites.

[0069] As described above, commercially available pack formulations of natural enemy support materials contain sugar mites as food mites for the natural enemy insect, Phytoseiulus swirskii, and also contain bran or the like as food for the sugar mites. Sugar mites are known to infest sugar, miso, and the like, and are known not to spread over a wide area. In the tests of the examples, this pack formulation was used to which, in addition to sugar mites, grain mites were added as food mites. Specifically, for the test, 2 to 40 grain mites were added to approximately 500 to 1,500 sugar mites contained in the pack formulation.

[0070] Here, it is known that when the conditions are right, astigmatism mites can multiply in large numbers in just 1 to 2 weeks. For example, they ingest wheat flour, breadcrumbs, baking powder, mixed flour containing seasonings, sugar, confectionery, etc., and appear in these foods. Among these, Tyrophagus putrescentiae are known to be the most widespread. Tyrophagus putrescentiae were used in the tests of the present invention. The inventors considered it important to control the proliferation of sugar mites and astigmatism mites, which occurs when the composition of the bait mites in the pack formulation is changed to multiple species as described above, so as to contribute to achieving the object of the present invention.

[0071] The inventor first considered that an effective method for controlling the proliferation of C. sugarcane and Acarus mites would be to reduce the initial density of C. sugarcane and Acarus mites in the pack formulation by significantly reducing the number of Acarus mites compared to the number of C. sugarcane mites. By configuring the pack formulation in this way, the proliferation of C. sugarcane mites would be promoted in the pack formulation first, and then, as the proliferation of C. sugarcane mites slows down, Acarus mites will proliferate in large numbers, and as a result, bait mites will remain abundant in the pack formulation for a long period of time.

[0072] Furthermore, with the above-mentioned configuration, the Swirlskii mites and bait mites that have multiplied in large numbers within the pack formulation will come out of the pack formulation into the sealed space of the main body of the natural enemy support material in which the pack formulation is placed. The inventors predicted that if, when this state occurs, it is possible to effectively provide food for the bait mites within the sealed space, it will be possible to further multiply the Swirlskii mites, a natural enemy insect, within the sealed space, and as a result, it will be possible to increase the number of natural enemy insects released from the sealed space and to extend the period of release.

[0073] Based on the above prediction, the inventors have conducted extensive research and found that the water-retaining materials that are placed in conventional techniques to maintain high humidity in enclosed spaces can be effectively utilized. Specifically, the inventors carried out a test to determine whether the sugars introduced into the enclosed space can effectively function as food for mites by adding sugars to the water used to retain water in the water-retaining material and placing the water-retaining material in this bait-containing form in the enclosed space of the main body of the natural enemy support material. As a result, they found its effectiveness. The procedure is shown below.

[0074] In the examples of the present invention, various sugars were dissolved in 100 ml of water used for water retention to prepare an aqueous solution for water retention. The resulting aqueous solution was then used to retain water in water-retaining materials. Five water-retaining materials were then retained until they weighed 5 to 7 g, and the resulting water-retaining materials containing bait were placed in an enclosed space. These natural enemy support materials were then placed in containers with a humidity controlled at 75% RH and placed in an incubator set at 25°C. The containers were replaced every week to continue the release test, and the number of natural enemy insects, Phytoseiulus swirskii, released into the replaced empty containers was counted, and this number of released mites was used to verify the release status of the natural enemy insects. In the comparative examples, natural enemy support materials were used that were composed of water-retaining materials weighing 5 to 7 g and retained only in water. As described above, a small amount of sugar mites and acarid mites were added as bait mites to the package formulation contained in this natural enemy support material. For reference, we also used only the pack formulation contained in a commercially available natural enemy support material, placed it in a container with humidity controlled at 75% RH as described above, and checked the release of the natural enemy insect, Phytoseiulus swirskii, from the pack formulation. Note that the conventional pack formulation only contains sugar mites as bait mites.

[0075] First, we placed bait-containing water-retaining materials, which had been moistened with a highly concentrated aqueous solution of sugars, inside the enclosed space of the natural enemy support material. Specifically, we prepared aqueous solutions containing 50 g of sugar dissolved in 100 ml of water. We used naturally occurring sugars such as trehalose, honey, brown sugar, and molasses, all dissolved in high concentrations. We then used each of the resulting solutions to moisten a superabsorbent polymer (water-retaining material) so that five pieces weighed 5–7 g. These bait-containing water-retaining materials were then used for testing. 1 ml of a fungicide was added to each of the solutions. Fungicides have the effect of inhibiting the growth of various microorganisms, such as gram-positive bacteria, gram-negative bacteria, and mold, that can cause spoilage of bait-containing water-retaining materials. Preferably, these antifungal agents are approved as food additives. In the following tests, Desfan-10 (trade name: manufactured by Matsuo Pharmaceutical Co., Ltd.), a naturally derived antibacterial preparation extracted from grapefruit seeds, was used as one of the antifungal agents that met these conditions. Hereinafter, this may be simply referred to as the antifungal agent.

[0076] The test results confirmed that, depending on the type of sugars contained in the aqueous solution used for water retention, the natural enemy insect, Phytoseiulus swirskii, was released in large numbers from the beginning and continuously for 10 to 13 weeks from the start of the test. In contrast, in the comparative example using a water-retaining material without bait, in which five pieces were retained with water to weigh 5 to 7 g, the number of insects released was lower than in the example, and the number of insects released did not increase after 8 weeks. For reference, in a test using only the pack formulation, the release period of the natural enemy insect, Phytoseiulus swirskii, was approximately 4 weeks. Furthermore, in a confirmation test using only the pack formulation in an environment with a humidity of approximately 40% RH, the release period was approximately 2 weeks, and the number of Phytoseiulus swirskii released was very low. These results confirm that increasing the humidity of the environment in which the pack formulation was placed to 75% RH was an effective means of prolonging the release period of natural enemy insects and increasing the number of mites released.

[0077] The total number of natural enemy insects released is shown in Table 1 below, which is the cumulative number of Phytoseiulus Swirskii mites counted during the release period of the mites. As a result, in the comparative example using a water-retaining material without bait that had been retained with water until it reached 5 to 7 g, the release period was 8 weeks and the total number of natural enemy insects released was 587.8, as shown in Table 1. In contrast, as shown in Table 1, when the material was retained with an aqueous solution containing a sugar, the release period and the number of natural enemy insects released could be significantly increased regardless of the sugar used.

[0078] The "total number of natural enemy insects released during the period" in Table 1 is the arithmetic mean value obtained by counting the cumulative total number of Phytoseiulus Swirskii mites for each test as described below, repeating the same test five times, and using the cumulative total counted for each test. That is, for each test, five natural enemy support materials (5 to 7 g) containing different sugars in the aqueous solution used for water retention were used, and the number of adult female Phytoseiulus Swirskii mites released into empty containers replaced every week was counted. This procedure was repeated until release was complete, and the cumulative total of the count results obtained was used as the cumulative total for that test. The number in parentheses for "total number of natural enemy insects released during the period" in Table 1 is the increase ratio calculated based on the cumulative count result (587.8 mites) of the comparative example conducted using a natural enemy support material retained in water.

[0079] TIFF0007808328000001.tif68170

[0080] As shown in Table 1, it was verified that adding sugars, which serve as food for mites, to the aqueous solution used to retain water in the water-retaining material effectively contributes to extending the release period of natural enemy insects and increasing the total number of insects released. Specifically, it was confirmed that the release period was extended by 2 to 5 weeks and the total number of insects released could be increased by approximately two times compared to the comparative example in which a water-retaining material without food was used.

[0081] In integrated pest management (IPM), which involves propagating natural enemy insects and using them to control pests, it is desirable to reduce running costs as much as possible and control pests economically. In contrast, as shown in the test results above, the present invention has been able to effectively propagate natural enemy insects by using safe materials, and is expected to be a technology that can make the use of natural enemy support materials used to control pests more efficient.

[0082] However, in the above test, a high-concentration aqueous solution of 50 g of sugar dissolved in 100 ml of water was used to retain water in the water-retaining material. To reduce the running costs of IPM, it is desirable to use a smaller amount of sugar. Therefore, the inventors conducted a test to examine the release of natural enemy insects when a water-retaining material containing a reduced amount of sugar was used, using the same method as described above. The results are summarized in Table 2. For trehalose, the results for the case where the high-concentration aqueous solution shown in Table 1 was used to retain water in the water-retaining material are also included.

[0083] TIFF0007808328000002.tif82170

[0084] As shown in Table 2, we investigated whether it was possible to prolong the release period of natural enemies and increase the total number of released insects by using water-retaining materials containing a dilute aqueous solution of 1 g of sugar dissolved in 100 ml of water. Specifically, the release test was conducted in the same manner as described above, except that various sugars were added to the aqueous solution used to retain the water in the materials, and the concentration of the sugars was diluted. That is, the test was conducted five times at 75% RH and 25°C. As shown in Table 2, it was confirmed that the number of released insects was improved when monosaccharides such as glucose and fructose, disaccharides such as trehalose and sucrose, or sugar alcohols such as sorbitol and erythritol were used as sugars. As shown in Table 2, when trehalose, fructose, sucrose, and erythritol were used, the number of released insects (female adult Phytoseiidae) in the containers each week was greater than the number released in the containers the previous week, for at least 10 weeks. From this, it was confirmed that sugars contribute to the continued proliferation of Phytoseiulus swirskii within the natural enemy support material and within the container containing the natural enemy support material, even when the water-retaining material is retained using a dilute aqueous solution.

[0085] As mentioned above, sugars are found to be useful substances that can make it possible to continuously release a large number of natural enemy insects, as targeted by the present invention, over a long period of time, by using water containing food to retain moisture in the water-retaining material, not only when a concentrated aqueous solution with a high bait content is used to hydrate the water-retaining material and the material is placed in a bunker sheet, but also when a dilute aqueous solution with a low bait content is used to hydrate the water-retaining material and the material is placed in a bunker sheet.

[0086] Furthermore, the results of the above tests showed that the use of a highly concentrated sugar solution produced a greater effect of the present invention, but even when a sugar solution with 1 / 50th the concentration was used, the effect was slightly reduced, but the intended effect of the present invention was clearly achieved. From this, it is expected that the effects of the present invention can be more effectively achieved by using a sugar solution with an appropriate intermediate concentration as discussed above. It is also expected that the effects of the present invention can be more effectively achieved by examining more optimal types of sugars or combinations of sugars with other substances containing nitrogen components.

[0087] Therefore, the inventors conducted research to determine whether using an aqueous solution containing a sugar with the above-mentioned effect plus another substance for water retention would increase the number of natural enemy insects released or enable the natural enemy support material to maintain a good release of natural enemy insects for a long period of time. Specifically, trehalose was used as a representative sugar, and a dilute concentration (1 g of sugar dissolved in 100 ml of water) was investigated to determine whether adding 1 g of a nitrogen-containing substance would improve the effect. Protein-derived peptone was also investigated as a nitrogen (N)-containing substance. As shown in Table 2, the results confirmed that using a water-retaining material containing an aqueous solution containing a nitrogen (N)-containing substance in addition to trehalose could increase the number of natural enemy insects, Phytoseiulus swirskii, released, compared to using a small amount of sugar alone. Other nitrogen (N)-containing substances that can be used include urea, yeast, amino acids, and vitamins. Among these, the addition of yeast was found to be effective. This point will be discussed later.

[0088] The results of the study, which was conducted using Phytoseiulus swirskii as a representative example of phytoseiid mites, a natural enemy insect, in Tables 1 and 2 shown above, are shown in Figure 1, which is a graph of the cumulative number of phytoseiid mites released per week (number of adult female natural enemy insects) measured as described above. As shown in Figure 1, the intended effect of the present invention can be achieved by using an aqueous solution of a sugar to retain water in the water-retaining material to be contained in the bunker sheet specified in the present invention. In Figure 1, trehalose is abbreviated as "Treha", erythritol as "Erys", and fructose as "Fluc".

[0089] (Examination of natural enemy insects other than phytoseiid mites) The commercially available pack of natural enemy support material used in each of the above-mentioned tests contained the natural enemy insect Phytoseiulus swirskii. In a more preferred embodiment of the present invention, as described above, this pack was modified to include, in addition to the sugar mites contained in the commercially available pack, a significantly smaller number of acarid mites as prey for the swirskii mites. Furthermore, a water-retaining material containing bait maintained with an aqueous solution containing sugars was placed within the natural enemy support material. This enabled the stable release of Phytoseiulus swirskii mites over a long period of time, and a stable increase in the total number of mites released from a single natural enemy support material. As described above, simply placing a water-retaining material containing bait maintained with an aqueous solution containing sugars within the natural enemy support material can enhance the release of natural enemy insects. As described above, the use of a water-retaining material containing bait maintained with an aqueous solution containing sugars in combination with a different type of bait mite can further enhance the release of natural enemy insects.

[0090] Furthermore, in another configuration example of the present invention, it has been found that by adding a simple means, in addition to the above-mentioned effect, a completely different effect can be obtained, as described below. That is, it has been found that a single natural enemy support material can be used to effectively release both phytoseiid mites, such as Phytoseiulus swirskii, and other natural enemy insects that can be used to control other pests, different from phytoseiid mites. Specifically, the following study was conducted using Hypoaspis sp., a natural enemy insect of the Gamagridae family, as a natural enemy insect other than phytoseiid mites. As a result, the effectiveness of a natural enemy support material that combines two natural enemy insects, phytoseiid mites, such as Phytoseiulus swirskii, and Gamagridae, such as Hypoaspis sp., was confirmed. The Hypoaspis sp., a natural enemy insect of the Gamagridae family, used in the above study was obtained by raising field-collembolans that had also been collected in the field and grown indoors using baker's yeast or the like as a food source.

[0091] A small number of the aforementioned Gamas mites (Hypoaspis sp.) were added to a pack formulation modified with the addition of acorn mites as bait, which had previously been shown to be effective in the experimental study. Specifically, 2 to 8 Gamas mites were added to approximately 250 Phytoseiulus Swirskii mites in the pack formulation. A water-retaining material filled with distilled water was then added to the main body of the natural enemy support material, containing bait, as in the previous study. Using this natural enemy support material modified with bait mites and natural enemy insects, the containers were replaced weekly, as in the previous study, and the number of Gamas mites released from each container was counted to confirm the Gamas mites' proliferation status. As shown in Figure 2, there were almost no Gamas mites in the containers until week 3, but release began after week 4. The number of Gamas mites released rapidly increased and remained stable until around week 9 to 10. This shows that in the above test, as shown in Figure 1, when the water retention material was filled with distilled water, the release of Phytoseiulus swirskii mites began one week after the test, and the increase in the number of released mites almost stopped after four weeks, while the release of Gamas mites began after that.

[0092] The usefulness of using an aqueous solution containing sugars to retain water in a water-retaining material for the proliferation (release) of Gamas mites was confirmed as follows. An aqueous solution was prepared by adding 50 g of honey to 100 ml of distilled water, and an aqueous solution was prepared by adding 1 g of trehalose and 1 g of urea to 100 ml of distilled water. Water-retaining materials were retained in these aqueous solutions, and the proliferation (release) of Gamas mites was confirmed in the same manner as in the case of Phytoseiulus swirskii. 1 ml of a fungicide was added to each of the above aqueous solutions. The results are shown in Table 3 and Figure 2.

[0093] TIFF0007808328000003.tif42170

[0094] (Examination of feeding conditions for water-retaining materials with reduced running costs) The commercially available natural enemy support material (product name: Swirlbanker) used in each of the above-mentioned tests contained a pack of Phytoseiulus swirskii as a natural enemy insect and one species of phytoseiid mite as a bait mite. In a preferred embodiment of the present invention, as described above, a small number of acarid mites are added to the commercially available pack of phytoseiid mite as bait mites in addition to phytoseiid mite. Furthermore, a moisture-retaining material containing bait, retained in an aqueous solution containing sugars, which is a characteristic of the present invention, is placed within the natural enemy support material. This configuration allows for an increased total number of Phytoseiid swirskii mites released. Meanwhile, as described above, considering the impact on food safety and producer health, the widespread adoption of IPM technology is urgently needed. To achieve widespread adoption of IPM, it is important to achieve stable IPM effects while also reducing IPM running costs. To achieve this, it is desirable to reduce the amount of sugar used and, further, to reduce the types and number of bait mites contained. Therefore, the inventors used a water-retaining material containing bait that was kept moist using an aqueous solution with a reduced amount of sugar, in the same manner as described above, and conducted tests to examine the release of natural enemy insects when no acarid mites were added, in other words, when the only difference was that the water-retaining material of a conventional natural enemy support material was that it contained bait, and confirmed the effectiveness of using a water-retaining material containing bait.

[0095] Specifically, we used a commercially available pack of natural enemy support material (product name: Swirl Bunker) and examined the release of Phytoseiulus swirskii from the bunker sheet in the same manner, except that the water-retaining materials contained in the pack were retained with the following five solutions: water, a solution of 100 ml of water plus 1 g of fructose and 1 g of peptone, a solution of 100 ml of water plus 1 g of sucrose and 1 g of peptone, a solution of 100 ml of water plus 1 g of trehalose and 1 g of peptone, and a solution of 100 ml of water plus 1 g of trehalose and 1 g of brewer's yeast. The five solutions used were all low in concentration: water, saccharides, and nitrogen-containing peptone or yeast. Each solution contained 1 ml of a mildewproofing agent. The amount of solution used to retain the water in the water-retaining materials was the same, 2–3 g. The test was repeated 8 to 10 times at 25°C and 50 to 60% relative humidity, and the number of Phytoseiulus swirskii mites released from the bunker sheet was counted and the average numbers were compared. The results are summarized in Table 4.

[0096] TIFF0007808328000004.tif61170

[0097] <Evaluation results> As shown in Table 4, we found that by using a moisture-retaining material made by hydrating it with an aqueous solution containing dilute concentrations of sugars and nitrogenous components, the total number of natural enemy insects released increases, just as with conventional pack formulations that do not add acarid mites to the bait, even when only sugar mites are used as the natural enemy insect bait. The addition of brewer's yeast, which contains nitrogenous components, was particularly effective, and we confirmed that combining it with a dilute concentration of trehalose produced the greatest increase in total number released. Meanwhile, the release period of the natural enemy insect, Phytoseiulus swirskii, was roughly the same in each group, at around six weeks, and there were no significant differences due to the difference in the moisture-retaining solution used in the moisture-retaining material. The inventors believe that the reason for this is that the test results shown in Table 4 were obtained by adding a small number of acarid mites in addition to sugar mites to the bait mites in the pack formulation, unlike the previous test examples, and furthermore, the amount of liquid used to retain water in the water-retaining material was small, at 2 to 3 g, so that after four weeks from the start of the test, the proliferation of sugar mites, which are the bait mites, weakened, and thereafter there was a shortage of food for the natural enemies.

[0098] The commercially available natural enemy support material used in each of the above-mentioned tests was for "control of whiteflies and thrips," and the pack formulation of this natural enemy support material contained the natural enemy insect Phytoseiulus swirskii and one species of prey mite, Caryopsis sacchariflorus. Meanwhile, the commercially available natural enemy support material pack formulation for "control of spider mites" contained the natural enemy insect Phytoseiulus californicus and the prey mite, Glycine maxillaris. As mentioned above, previous studies of the present invention found that by using a commercially available pack formulation and placing a water-retaining material containing bait, which was moistened with an aqueous solution containing sugars, within the natural enemy support material, the total number of Phytoseiulus swirskii mites released could be increased compared to the comparative example in which a water-retaining material without bait was used. Furthermore, it was found that by adding a small number of acarid mites as bait mites to the commercially available pack formulation contained in the natural enemy support material in addition to the sugar mites contained in the pack formulation, the high proliferation effect of Phytoseiulus swirskii can be made more stable and sustained.

[0099] In order to promote the use of IPM (integrated pest management), it is desirable to have a technology that can steadily increase the number of various types of phytoseiid mites released and that can deal with various types of difficult-to-control micro-pests. Therefore, the inventors conducted a test to examine the release of Phytoseiid mite Miyako, a different species of Phytoseiid mite classified as a Phytoseiidae, as a natural enemy insect, using a method similar to that used to confirm the proliferation effect of Phytoseiid mite Swirskii described above. The inventors also conducted a test to examine the release of Phytoseiid mite Miyako when a water-retaining material containing bait was used, which was retained with an aqueous solution containing a reduced amount of sugar. Furthermore, according to the inventors' study, when Phytoseiid mite Miyako was used as a natural enemy insect, adding acarid mites to the bait mites in the pack formulation did not have the same effect on the proliferation of natural enemy insects as in the case of Phytoseiid mite Swirskii. Therefore, as described below, a test was conducted using a water-retaining material containing bait, without adding acarid mites to the bait mites.

[0100] Specifically, we investigated the release of Phytoseiulus californicus from commercially available natural enemy support materials (bunker sheets) containing a pack containing Phytoseiulus californicus mites. The water-retaining materials contained in the bunker sheets were similarly treated, except that the water-retaining materials were retained with the following two liquids: water alone and a dilute solution containing water, sugars, and nitrogen-containing yeasts (100 ml of water, 1 g of trehalose, and 1 g of baker's yeast). Each solution contained 1 ml of a mildewproofing agent. The amount of liquid used to retain the water in the water-retaining materials was the same (4–5 g). The test was repeated seven times at 25°C and 50–60% relative humidity. The number of Phytoseiulus californicus mites released from the bunker sheets was counted, and the average number was compared. The results are summarized in Table 5.

[0101] TIFF0007808328000005.tif36170

[0102] As shown in Table 5, we discovered that using a bait-containing moisture-retaining material containing dilute concentrations of trehalose and baker's yeast promoted the proliferation of the prey mite, Glycine maxillaris, even without the addition of acarid mites, and also led to an increase in the total number of prey mite, Phytoseiulus californicus, released, even without the addition of acarid mites. Furthermore, as shown in Table 4, using a bait-containing moisture-retaining material containing dilute concentrations of trehalose and brewer's yeast promoted the proliferation of the prey mite, Carpoglyphus sugarbergii, even without the addition of acarid mites, and also led to an increase in the total number of prey mite, Phytoseiulus swirskii, released, even without the addition of acarid mites. This confirms that the use of a bait-containing moisture-retaining material can increase the number of prey mite species released, regardless of the type of prey mite or whether acarid mites were added. Meanwhile, the release period of the prey mite, Phytoseiulus californicus, was roughly the same in all plots, at approximately 7 to 8 weeks, and there were no significant differences due to the difference in the moisture-retaining solution used in the moisture-retaining material.

Claims

1. A breeding device for natural enemy insects for improving the breeding of natural enemy insects that are natural enemies of difficult-to-control micro-pest insects, The main body has an enclosed space through which the natural enemy insects can enter and exit, and at least natural enemy insects, prey mites that serve as food for the natural enemy insects, a small pouch-shaped member containing at least food for the prey mites, a felt member for egg-laying, and a moisture-retaining material made of a moisture-slow-releasing water-retaining material are arranged inside the main body, The natural enemy insect is a phytoseiid mite of the family Phytoseiidae belonging to the suborder Gamasidae, a representative example of which is Phytoseiulus swirskii, The bait mite is at least one species of Astigmatid mite of the family Carbuncleidae, which belongs to the suborder Astigmatidae, of which Carbuncle is a representative example; The water-retaining material contains feed that has been watered using an aqueous solution containing sugars. A breeding device for natural enemy insects.

2. The natural enemy insect breeding device described in claim 1, wherein the bait mites further include one type of acarid mite of the Astigmatidae family belonging to the suborder Acaridae, of which Astigmatism is a representative example, and the initial density of the acarid mite is configured to be smaller than the initial density of the sugar mite.

3. 3. The device for breeding natural enemy insects according to claim 2, wherein the initial density of the sugar mites is 1,000 and the initial density of the astigmatids is 2 to 40.

4. 3. The breeding device for natural enemy insects according to claim 1 or 2, wherein the sugar is at least one selected from the group consisting of trehalose, honey, brown sugar, molasses, glucose, fructose, sucrose, sorbitol and erythritol.

5. 3. The breeding device for natural enemy insects according to claim 1, wherein the water-retaining material contains food that has been kept moist using an aqueous solution containing a substance that contains a nitrogen component in addition to the sugars.

6. 6. The device for breeding natural enemy insects according to claim 5, wherein the substance containing a nitrogen component is at least one selected from the group consisting of urea, peptone, yeasts, amino acids and vitamins.

7. A breeding device for natural enemy insects as described in claim 1 or 2, wherein the water-retaining material is a granular water-retaining material made of highly absorbent resin, and five pieces are made to retain water so that the total weight is adjusted to 4 to 7 g.

8. The natural enemy insect breeding device according to claim 1 or 2, wherein the natural enemy insects further include Gamasid mites of the Gamasidae family belonging to the Gamasida suborder, and the initial density of the Gamasid mites is 1 to 3 per 100 of the one type of phytoseiid mites.

9. A method for propagating phytoseiid mites to improve the number and duration of release of natural enemy insects used in controlling difficult-to-control micro-pests using natural enemy insects, comprising:

3. A method for breeding phytoseiid mites, comprising using the breeding device for natural enemy insects according to claim 1 or 2, and maintaining an increase in the population of phytoseiid mites, which are natural enemy insects, for a long period of time.

10. 10. A method for propagating phytoseiid mites and Gamas mites, which is used when using natural enemy insects to control difficult-to-control micro-pests, and which involves simultaneously releasing phytoseiid mites as natural enemy insects and Gamas mites, characterized in that the method is configured to use the natural enemy insect propagating device described in claim 8 to increase the population of phytoseiid mites, and then increase the population of Gamas mites after the proliferation of the phytoseiid mites has weakened.

11. 3. A method for controlling minute pests that are difficult to control, comprising installing the breeding device for natural enemy insects according to claim 1 or 2 in an area where the minute pests that are difficult to control live.

Images