Arthropod trap and arthropod capturing method

Abstract

To provide a trap capable of efficiently capturing arthropods, which live in areas such as a water surface of a paddy field etc. and aquatic and bog plants, so as to classify or count them, and a capturing method.SOLUTION: An arthropod trap includes a body that comprises a bottom, a roof part and a side and that has a hollow structure. The body has at least one opening provided in the side part. A top surface of the bottom is provided with an adhesive region that is coated with a pressure-sensitive adhesive. An undersurface of the bottom is provided with a float material. The arthropod trap is used for an arthropod capturing method.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a trap for trapping arthropods such as spiders that inhabit water surfaces and the like, and a method for trapping arthropods such as spiders that inhabit water surfaces and the like. [Background technology]

[0002] Arthropods such as spiders and insects that live in rice paddies, especially wolf spiders, are known as natural enemies that prey on rice pests such as planthoppers and leafhoppers. Wolf spiders live in high population densities in rice paddies and are highly efficient at preying, so they are expected to be used to control rice pests. In order to effectively use these natural enemies for pest control, it is important to understand the occurrence status in rice paddies. In the past, a method was used to directly visually observe and count the natural enemies on the rice plants and in their vicinity in the rice paddies in order to understand the occurrence status of natural enemies. However, this method requires instantaneous identification of the type of natural enemy, which is difficult to implement unless the surveyor is experienced. In addition, due to the behavioral characteristics of the natural enemies, the results of visual observation and counting can vary greatly depending on the weather and time of day, making it difficult to conduct a survey with high accuracy. Another method used is to capture natural enemies by sucking them up using an engine blower or similar, but this method has problems such as the cumbersome suction process and the subsequent separation of samples, and the spiders fleeing when the researcher approaches or when the engine blower makes noise, making it difficult to capture them efficiently.

[0003] Another method for investigating the occurrence of crop pests is known to be a method of setting traps. In this method, a trap is set at a predetermined position for a predetermined time, and then the captured pests are observed. For example, by setting the predetermined time to several hours to several days, the type and number of captured targets can be less affected by the time of day and weather. In addition, since the targets remaining in the trap are classified and counted, even an unskilled investigator can easily carry out the method. As an investigation method using such traps, Non-Patent Document 1 discloses a method in which a polystyrene foam block coated with an adhesive substance is floated on the water surface of a paddy field, and the spiders captured are counted and observed. In addition, Non-Patent Document 2 discloses a method in which a pitfall trap is floated on the water surface of a pond to capture the spiders living there. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] MJ Oraze, et al., J. Arachnol., Vol.16: 331-337 (1988) [Non-Patent Document 2] AK Graham, et al., J. Arachnol., Vol.31: 78-89 (2003) Summary of the Invention [Problem to be solved by the invention]

[0005] The trap used in the method shown in Non-Patent Document 1 has an exposed sticky surface, but wandering spiders, which are natural enemies of rice pests, have a behavioral characteristic of moving around looking for places to hide from predators such as birds, making it difficult to efficiently capture them on an exposed sticky surface. In addition, the method shown in Non-Patent Document 2 has a cup-shaped trapping part, so it is suitable for installation in ponds with a certain degree of water depth, but cannot be installed in shallow rice paddies.

[0006] The object of the present invention is to solve the above-mentioned conventional problems and to provide a trap and a trapping method that can efficiently capture arthropods that live on the water surfaces of rice paddies and other areas, and in aquatic and wetland plants, in order to classify and count them. [Means for solving the problem]

[0007] In order to solve the above problems, the present inventors conducted extensive research and discovered that a sticky trap that has a bottom coated with an adhesive and a roof covering it and can float on the water surface can be used to efficiently capture arthropods living in rice paddies. The present invention is based on this new finding, and specifically provides the following inventions. (1) An arthropod trap for capturing arthropods whose habitat is on the water surface and in aquatic or wet plants, comprising a body having a hollow structure with a bottom, a roof and sides, the body having at least one opening on the side, an adhesive area on the upper surface of the bottom having an adhesive applied thereto, and a floating material on the lower surface of the bottom, the body and the floating material being formed from a water-resistant material and capable of floating on the water surface so that the upper surface of the bottom is approximately horizontal. (2) A trap as described in (1), further comprising a waterproof fixing string having one end attached to the main body or the floating material. (3) A trap as described in (2), further comprising a waterproof fixing member at the other end of the fixing string, the fixing member being an O-ring or an S-shaped hook, and capable of fixing the main body to a stake or a plant stem via the fixing string. (4) A trap described in any one of (1) to (3), wherein the height of the side portion is 0.5 to 10 cm. (5) A trap described in any one of (1) to (4), in which the upper surface of the roof portion is approximately horizontal. (6) A trap described in any one of (1) to (5), having at least two openings on the sides thereof, facing each other across the center of the body. (7) A trap described in any one of (1) to (6), in which at least one opening in the side portion extends to the lower end of the side portion. (8) A trap described in any one of (1) to (7), wherein the arthropod is a spider. (9) The trap described in (8), wherein the spider is a wolf spider. Effect of the Invention

[0008] According to the present invention, it is possible to provide a trap and a trapping method that can efficiently capture arthropods that live on the water surfaces of rice paddies and other areas, and in aquatic and wetland plants, in order to classify and count them. [Brief description of the drawings]

[0009] [Figure 1] 1 is a perspective view showing the appearance of an embodiment of an arthropod trap of the present invention; [Diagram 2] 2 is a cross-sectional view taken along the line AA' of FIG. [Diagram 3] 2 is a cross-sectional view taken along the line BB' of FIG. [Figure 4] 10 is a photograph showing the appearance of another embodiment of the arthropod trap of the present invention, in which the arthropod trap is actually installed in a paddy field. [Diagram 5] 13 shows a photograph of the sticky area of ​​an arthropod trap after trapping arthropods in a rice field with another embodiment of the arthropod trap of the present invention. [Figure 6] 1 is a line graph showing the transition of the number of wolf spiders observed by the arthropod survey method of the present invention and the conventional survey method. The trend of the occurrence of wolf spiders was almost the same by the two methods, but the number of observations was clearly greater by the survey method of the present invention. [Figure 7] 1 is a line graph showing the transition of the number of captured natural enemies of rice pests observed using the arthropod survey method of the present invention. There are many water striders in early summer before the rice grows, and there are many wolf spiders from July to September when the rice is fully grown. [Figure 8] 1 is a graph showing the number of wolf spiders captured using the arthropod trap of the present invention and the arthropod trap with the roof removed. Approximately three times as many wolf spiders were observed in the arthropod trap of the present invention as in the trap with the roof removed. [Figure 9]1 is a graph showing the distribution of the preservation state of wolf spiders captured using the arthropod trap of the present invention and the arthropod trap with the roof removed. Wolf spiders were classified into group I, where only palps were observed, group II, where parts of the spider were observed, and group III, where the complete spider was observed, and the proportion of the number of individuals in each group out of the total number of wolf spiders observed was calculated. [Figure 10] This graph shows the number of wolf spiders captured using arthropod traps with different base-to-roof heights. The numbers in the graph are the average number of wolf spiders captured in the two traps in each treatment area. Among the traps examined, the traps with higher roof heights captured more wolf spiders. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] <1. Arthropod trap> The arthropod trap of the present invention comprises a body having a hollow structure with a bottom, a roof and sides, the body having at least one opening on the side, an adhesive area on the upper surface of the bottom where an adhesive is applied, and a floating material on the lower surface of the bottom.

[0011] In this specification, "arthropods" refers to animals belonging to the phylum Arthropoda, including insects, crustaceans, spiders, centipedes, etc. The arthropods to be captured by the arthropod trap of the present invention are arthropods that live on the water surface of rice paddies and the like, and on aquatic and wet plants, particularly insects and spiders. Furthermore, there are spiders belonging to the family Lycosidae, the family Linyphiidae (subfamily Lycosidae), and the family Tetragnathidae (genus Acanthurus), which can be natural enemies of pest insects of rice paddies, and insects belonging to the family Aquatic Hemiptera, including the family Staphylinidae, and the family Dytisciidae, including the family Dytisciidae.

[0012] In order to accurately investigate the habitat of natural enemies of rice pests in paddy fields, it is necessary to observe as many natural enemies as possible. The arthropod trap of the present invention efficiently captures the arthropods, making it possible to observe many natural enemies and to investigate the habitat of natural enemies with higher accuracy.

[0013] In this specification, the up-down direction of an arthropod trap (hereinafter also simply referred to as "trap") is the up-down direction perpendicular to the water surface when the trap is floating on the water surface. In this specification, "height" refers to the length perpendicular to the water surface. The "bottom" of the trap body of the present invention refers to the approximately horizontal part that constitutes the lowermost part of the trap body, the "roof" refers to the part that constitutes the uppermost part of the trap body with a gap above the bottom and covers all or part of the upper part of the bottom, and the "side" refers to the side part sandwiched between the outer edge of the bottom and the outer edge of the roof.

[0014] One embodiment of the trap of the present invention is shown in Figures 1 to 3. The trap of the present invention will be described below based on the embodiment of Figures 1 to 3, but it is not intended that the trap of the present invention be limited to these embodiments. Figure 1 is an external perspective view of one embodiment of the trap of the present invention, Figure 2 is a cross-sectional view taken along line A-A' in Figure 1, and Figure 3 is a cross-sectional view taken along line B-B' in Figure 1.

[0015] The main body 11 of the trap 10 of the present invention has a hollow structure formed by the members constituting the bottom 12, roof 13, and side 14. The bottom 12, roof 13, and side 14 are preferably made of thin plate-like members. Examples of materials for forming such thin plate-like members include paper, plastic, rubber, metal, and wood. Since it is desired to separate only the members in the adhesive region from the other members in order to classify and count the captured arthropods, a material that can be easily separated with scissors or the like is preferable. In addition, since the trap is to be floated on the water surface for a predetermined period of time, a water-resistant material is preferable. As such a material, paper (particularly cardboard, etc.), synthetic paper (Yupo (registered trademark) paper, etc.), plastic (particularly polypropylene, polyethylene, polyethylene terephthalate, polyvinyl chloride, etc.), and alternative plastic (LIMEX (registered trademark), etc.) coated with a waterproof paint or the like can be preferably used. It is preferable that the thin plate-like member is opaque, particularly one with low light transmittance, so that the inside cannot be seen at least from above the trap.

[0016] The bottom portion 12, the roof portion 13, and the side portion 14 may be formed by folding and assembling a single thin plate-like member, but are not limited thereto, or may be formed as separate thin plate-like members and connected together. The bottom portion 12, the roof portion 13, and the side portion 14 are preferably assembled as a single member.

[0017] The height of the side 14 of the main body 11 is preferably 0.5 to 10 cm, particularly 2.0 to 6.0 cm, and further preferably 2.0 to 5.0 cm. Since wolf spiders and the like prefer narrow and dark places, providing a roof has the advantage of making it easier for them to enter the adhesive area inside, but on the other hand, if the height of the side is made too low, problems may arise in that it is more difficult for wolf spiders and the like to enter and the roof is more likely to adhere to the adhesive area. On the other hand, if the height of the side is made too high, problems may arise in that light is more likely to enter through the opening and that the device is more likely to tip over due to crosswinds, etc. By setting the side at the above height, tipping, etc. is less likely to occur, and more efficient capture is possible.

[0018] At least one opening 16 is provided in the side portion 14 as an entrance for arthropods. Preferably, at least two openings 16 are provided in the side portion 14, facing each other across the center of the main body 11. The openings 16 preferably extend to the lower end of the side portion 14 so that arthropods can enter more easily. The shape and size of the openings 16 are not particularly limited, but the main body 11, the side portion 14, and the openings 16 can be easily formed by forming the main body into a square tube with both ends open, as in the illustrated example, and making the open parts into the sides. Note that more openings 16 may be formed, but the total area of ​​the openings 16 is preferably 70% or less, particularly less than 50%, of the total area of ​​the side portion 14 in order to reduce water wetting of the adhesive region S or to keep the inside of the main body dark.

[0019] The adhesive region S in the trap 10 refers to a region having an adhesive layer 15 formed on all or part of the upper surface of the bottom 12 of the main body 11, to which an adhesive is applied. As in the illustrated example, the adhesive may be applied directly to the member constituting the bottom 12, but it may also be formed, for example, by applying the adhesive to a thin plate-like member other than the bottom 12 and fixing it to the upper surface of the bottom 12 so that the adhesive is on the upper surface. The adhesive region S is preferably disposed at least near the side opening 16, and more preferably disposed over the entire upper surface of the bottom 12. In the adhesive region S, the adhesive may be applied in a uniform layer over the entire region as in the illustrated example, but it may also be applied in a pattern such as dots, stripes, or wavy stripes (not shown).

[0020] The "adhesive" applied to the adhesive region S refers to a non-drying substance that has adhesiveness at room temperature and does not have fluidity or water solubility at room temperature. The adhesive is not particularly limited as long as it satisfies the above conditions, but examples include natural rubber, synthetic rubber, ethylene-vinyl acetate copolymer, polyisobutylene, polybutene, atactic polypropylene and other liquid polymers, tackifier resins such as petroleum resins, etc. These substances can be used alone, in the presence of an appropriate solvent, without a solvent, by heating, or by mixing and applying in a latex or emulsion state. In particular, the combination of styrene-butadiene block polymer and / or ethylene-vinyl acetate copolymer with a tackifier resin and a plasticizer, and the combination of polyisobutylene with liquid polybutene and atactic polypropylene have good adhesive properties, can be mixed by heating in a solvent-free system, and can be applied as is, so they can be used preferably. The viscosity (JIS K-6833 (1980)) of the adhesive applied to the trap of the present invention is preferably 2500 to 3300 P at 130°C.

[0021] The shape of the main body 11 may be any shape, such as a trapezoid, an inverted trapezoid, a triangle, a polygon, a semicircle, a square, etc., in cross section, so long as the lower surface of the bottom is approximately horizontal. The shape of the bottom of the main body is not particularly limited, but considering ease of assembly, etc., a rectangle is preferable. The size of the main body 11 is also not particularly limited, but since it is to be installed in a paddy field where rice is planted, the size of the bottom is preferably about 5 to 30 cm, particularly about 7 to 20 cm.

[0022] A floating material 17 is attached to the lower surface of the bottom 12 of the main body 11. The number, shape, and size of the floating material 17 are not particularly limited as long as the trap 10 can be floated while the bottom 12 of the main body 11 is kept horizontal. If the bottom 12 tilts, there is a risk that the adhesive will flow. In particular, as shown in the example, the floating material 17 is made flat and attached so as to cover the entire lower surface of the bottom 12, so that the bottom 12 can be kept horizontal. The structure of the floating material 17 can be any structure used as a normal floating material, such as a sealed hollow structure or a porous structure. The material of the floating material 17 is not particularly limited as long as it can impart water resistance, buoyancy, and rigidity to the floating material to maintain its shape on the water surface, but it is particularly preferable to use a material that is easy to process. Examples of such materials include polystyrene foam, EVA, polyethylene foam, and polyurethane foam. When the floating material 17 is flat, it is preferable that the size of the bottom surface of the floating material 17 is the same as the bottom surface of the main body 11. The buoyancy of the floating material 17 and the weight of the main body 11 are preferably adjusted so that when placed on the water surface, the upper surface of the bottom 12 of the main body 11 is positioned about 0.1 to 3 mm above the water surface.

[0023] The floating material does not necessarily have to be a separate member from the main body 11 as in the illustrated example. For example, the thin plate member constituting the bottom 12 of the main body 11 can be made of a material having the desired buoyancy and rigidity, so that the bottom 12 can function as a floating material (not shown).

[0024] Since the capture of natural enemies is continuously performed at a predetermined position, it is necessary to prevent the main body 11 from drifting away and moving from the predetermined position. For this reason, it is preferable to attach a fixing string 18 for fixing the main body 11 to a stake or the like. In the illustrated example, one end of the fixing string 18 is attached to an arbitrary position of the main body 11, and the other end is fixed to a stake or the like. The fixing string 18 may be attached to a floating material 17. The length of the fixing string 18 is not particularly limited, but it is preferable that it is about 10 to 50 cm. The material of the fixing string 18 is not particularly limited as long as it is water resistant, but it is preferable to use a PP string or the like that is easy to process and lightweight.

[0025] The other end of the fixing string 18 may be tied directly to a stake or the like, but is preferably fixed to the stake or the like via a fixing member 19. The fixing member 19 is not particularly limited as long as it can fix the fixing string 18 to the stake or the like, and a clip, a clothespin, an O-ring, an S-hook, or the like can be used. An O-ring, in particular an openable O-ring (generally also called a "card ring") is preferably used because it reduces the risk of the fixing string 18 getting wrapped around the stake or the trap tilting due to fluctuations in the water level in the rice paddy.

[0026] FIG. 4 shows another embodiment of the trap of the present invention actually installed in a paddy field. In the trap 40 of the embodiment shown in FIG. 4, the main body 41 is formed in a substantially rectangular tube shape with both ends open, with the bottom 42 being larger than the roof 43 and having a flat trapezoidal cross section. The side 44 has an opening 46b in addition to the opening 46a formed in the open portion. In this embodiment, too, an adhesive region S is provided on the upper surface of the bottom 42, and a floating material 47 is provided on the lower surface of the bottom 42. A fixing cord 48 and a fixing member 49 may be provided. In the illustrated example, the fixing member 49 is attached so as to surround a support P installed in the paddy field. Other aspects are the same as those of the embodiment shown in FIGS. 1 to 3.

[0027] The trap of the present invention is not limited to the above embodiments as long as the upper surface of the bottom having the main adhesive area floats approximately horizontally on the water surface and has a roof portion covering the bottom surface.

[0028] <2. How to capture arthropods> The method for capturing arthropods of the present invention (hereinafter also simply referred to as the "capturing method") is characterized in that the trap described in <1. Arthropod trap> is floated at a predetermined position on the water surface and retrieved after a predetermined period of time has passed. In addition, in the capturing method of the present invention, detailed conditions are the same as those in <1. Arthropod trap> unless otherwise specified.

[0029] In the trapping method of the present invention, the term "predetermined position" means that the trap is within a certain distance from a point determined on the water surface. More specifically, the trap is within 10 to 50 cm, more preferably 20 to 40 cm, from the point.

[0030] Moreover, the "predetermined period" refers to a period that is set in advance for installing the trap at a predetermined position, and specifically refers to 3 to 10 days, and more preferably 5 to 7 days.

[0031] More specifically, the capture method of the present invention comprises the following steps: (1) Preparing the trap (2) Setting the trap at a predetermined position on the water surface (3) Retrieving the trap

[0032] (1) Preparing the trap This is a step of preparing the trap described in <1. Arthropod Trap>. In preparing the trap, a commercially available pest trap may be used for the main body.

[0033] (2) Setting the trap at a predetermined position on the water surface The trap is floated at a predetermined position on the water surface. The location of installation is not limited as long as it is a place where a water surface exists, and examples thereof include rice paddies, waterways, rush fields, lotus fields, ponds and swamps, and pools. A rice paddy is preferable. The means for floating the trap at the "predetermined position" is not particularly limited, but for example, one end of a fixing string is attached to the trap body, and the other end of the fixing string is fixed to a stake or the like installed on the ground of the rice paddy. The floating trap is left untouched for a predetermined period, preferably 3 to 10 days, but it is preferable to periodically check whether it has sunk due to the influence of wind and rain, or whether the string has broken and fallen off the predetermined position.

[0034] (3) Retrieving the trap After a predetermined period of time has elapsed, the trap is retrieved. At that time, it is preferable to check whether the target arthropod or other organism has been reliably captured in the sticky area.

[0035] As described above, the trapping method of the present invention makes it possible to trap arthropods, particularly natural enemies of rice pests such as wolf spiders, in a very simple manner.

[0036] <3. Arthropod Survey Method> The arthropod survey method of the present invention (hereinafter also simply referred to as the "survey method") is characterized in that the trap described in <1. Arthropod trap> is floated at a predetermined position on the water surface, retrieved after a predetermined period of time, and the arthropods present in the sticky area are classified and counted. Note that, in the survey method of the present invention, detailed conditions, etc. are the same as those in <1. Arthropod trap> and <2. Arthropod capture method> unless otherwise specified.

[0037] More specifically, the investigation method of the present invention comprises the following steps. (1) Preparing the trap (2) Setting the trap at a predetermined position on the water surface (3) Retrieving the trap (4) Classifying and counting the arthropods present in the sticky area of ​​the trap. Steps (1) to (3) are the same as in <2. Arthropod capture method>.

[0038] (4) Classifying and counting the arthropods present in the sticky area of ​​the trap. The captured arthropods can be observed by opening the roof of the retrieved trap and exposing the sticky area. In particular, if the trap body is made of paper or plastic, the roof can be easily opened with scissors or the like. Furthermore, by separating only the bottom part from the other parts with scissors or the like, it becomes easier to store, observe, and photograph the trap.

[0039] The classification and counting of the captured arthropods may be performed visually, but may also be performed, for example, by image analysis using a computer. For example, image data of the obtained photo of the adhesive region can be input and collated with an image database of each arthropod pre-set on a computer to output the name of the closest arthropod. This collation may be performed using artificial intelligence (AI). When using AI, the image database can be used as training data to build an AI through machine learning using a known neural network, and the AI ​​can be used to identify the corresponding arthropod from newly input image data.

[0040] Figure 5 shows a photograph of the sticky area of ​​the trap of the present invention after it has captured arthropods in a rice paddy. As shown in Figure 5, the captured arthropods are fixed in place, making it easy to classify and count them. In addition, samples can be easily stored. In the example shown, 16 wolf spiders and 4 water striders can be identified.

[0041] By using the same traps and keeping them floating on the water surface for the same period, for example by trapping and observing multiple times at the same location in a rice paddy, it is possible to investigate seasonal changes in the types and numbers of arthropods living in the rice paddy. Alternatively, by trapping and observing at multiple locations during the same period, it is possible to investigate regional differences in the types and numbers of arthropods living in rice paddies. In either case, compared to conventional methods, this method is not affected by the level of skill of the investigator, and allows for simple and reliable investigations. EXAMPLES

[0042] <Example 1 Comparison with the conventional method (sample method)> In the same rice field, the number of wolf spiders identified using a survey method using the trap of the present invention (trap method) was compared with the number of wolf spiders identified using a conventional survey method based on visual observation (spotting method).

[0043] (1) Trapping method A trap for the trapping method was prepared. A 2 mm thick polystyrene foam board was cut to 181 x 86 mm and attached to the bottom of a commercially available cockroach trap (product name: Research PP Trap J (L), manufactured by Environmental Equipment Co., Ltd.) using a stapler. The size of the cockroach trap was 187 mm x 88 mm at the bottom and 28 mm high at the sides. One end of a 350 mm PP string was attached to the bottom of the cockroach trap using a stapler. A plastic O-ring (card ring) with a diameter of 30 mm was attached to the other end of the PP string to complete the trap.

[0044] The completed trap was floated on the water surface of the rice paddy. A post 11 mm in diameter and 1,800 mm in length was inserted deep into the paddy at a designated location, and the trap was attached by passing the loop at the end of the post through the post. The trap was replaced every week. The survey continued for 13 weeks in the same location.

[0045] The arthropods captured using the trapping method were classified and counted, including natural enemies other than wolf spiders, and the trends in the number of captured natural enemies in the tested rice paddies were observed.

[0046] (2) Visual approach During the same period as the trapping method, we visually counted the number of wolf spiders inhabiting random rice plants in the same paddy fields. Counting was performed once a week.

[0047] (3) Results Figure 6 shows the number of wolf spiders observed using the trap method and the visual method. The trends in the occurrence and seasonality of wolf spiders were almost the same for the two methods. However, the number of observations was clearly higher using the trap method. Observations using the trap method showed similar trends to those using conventional methods, and it was shown that the method allows for more accurate surveys.

[0048] Figure 7 shows the trends in the number of captured natural enemies using the trap method. There were more water striders in early summer before the rice plants started to grow, and more wolf spiders from July to September when the rice plants were fully grown. This is the same trend as observed with the conventional method.

[0049] <Example 2: Trap roof effectiveness verification test I> A trap was created in the same manner as in Example 1. As a comparative example, a trap without a roof was created by cutting off the roof and sides from the trap and exposing the adhesive area. The trap with and without a roof were floated in the same paddy field. After one week, both traps were retrieved and the number of captured wolf spiders was compared.

[0050] Figure 8 shows the number of wolf spiders captured in traps with and without roofs. Approximately three times as many wolf spiders were observed in the traps with roofs as in the traps without roofs.

[0051] <Example 3: Test to confirm the effectiveness of the trap roof II> A trap with a roof and a trap without a roof were created in the same manner as in Example 2. The trap with a roof and the trap without a roof were floated in the same manner in the same rice field. After one week, both traps were retrieved and the number of captured wolf spiders and the condition of each individual were observed.

[0052] Wolf spiders captured in traps with and without roofs were classified according to the condition of the individuals observed. Individuals in which only palps of wolf spiders were observed were classified as group I, individuals in which parts of the spider were observed were classified as group II, and individuals in which complete spiders were observed were classified as group III. The proportion of each group out of the total number of wolf spiders observed was calculated.

[0053] Figure 9 shows the percentage of each group among wolf spiders captured in traps with and without roofs. Many intact individuals were clearly observed in the traps with roofs. It became clear that using traps with roofs makes it possible to obtain specimens in good condition.

[0054] <Example 4: Consideration of trap roof height> A 0.2 mm thick plastic paper (manufactured by Tamiya Co., Ltd.) was folded to prepare a rectangular tubular member with a length of 187 mm, a width of 88 mm, and a height of 1.5 cm, and openings at both ends in the longitudinal direction (vertical direction). Similarly, rectangular tubular members with heights of 3.0 cm, 4.0 cm, and 6.0 cm were prepared. The entire bottom part having the adhesive area of ​​the cockroach trap used in Example 1 was cut out together with the backing paper, and attached with a stapler to the surface corresponding to the bottom upper surface of the plastic paper before assembling the rectangular tubular member, with the adhesive area facing upward. The plastic paper was then folded and fixed with a clip so that the whole was a rectangular tube. A 2 mm thick polystyrene foam board was cut to 181 x 86 mm and attached to the bottom surface of the rectangular tubular member using a stapler. One end of a 350 mm PP string was attached to the bottom using a stapler. A plastic O-ring with a diameter of 30 mm was attached to the other end of the PP string to complete various traps. Two traps each with heights of 1.5 cm, 3.0 cm, 4.0 cm, and 6.0 cm were made.

[0055] The completed traps were floated on the water surface of the rice paddies. A post 11 mm thick and 1,800 mm long was inserted deep into the paddy field at a designated location, and the traps were attached by passing the loop at the end of the post through the post. During the same period (August 12th to 19th), two traps of each height condition were set up and floated. After one week of floating, each trap was retrieved, and the number of wolf spiders attached to the sticky area was counted.

[0056] Figure 10 shows the number of wolf spiders captured in traps at each height condition. The numbers in the figure show the average number of wolf spiders captured by the two traps. Among the height conditions examined, the higher the roof was, the more wolf spiders were captured. It was confirmed that in order to capture wolf spiders more reliably, the roof height needs to be higher than a certain level. [Industrial Applicability]

[0057] The trap, trapping method and investigation method of the present invention are useful for utilizing natural enemies as a measure against pests of rice in rice farming, and can be used in industrial fields such as agriculture. They can also be used to investigate creatures in rice paddies as teaching materials for environmental education.

[0058] The present invention includes the following embodiments. (1) An arthropod trap comprising a body having a hollow structure with a bottom, a roof and sides, the body having at least one opening on the side, an adhesive area on the upper surface of the bottom where an adhesive is applied, and a floating material on the lower surface of the bottom. (2) The trap of (1), wherein the height of the side is 0.5 to 10 cm. (3) A trap of (1) or (2) having at least two openings on the sides, facing each other across the center of the body. (4) A capture device according to any one of (1) to (3), in which at least one opening in the side portion extends to the lower end of the side portion. (5) A trap of any one of (1) to (4), further comprising a fixed string having one end attached to the main body or a floating material. (6) A capture device as in (5) having a fixing member at the other end of the fixing string. (7) A method for capturing arthropods, comprising floating a trap of any one of (1) to (6) at a predetermined position on the water surface and recovering it after a predetermined period of time has elapsed. (8) A method for investigating arthropods, comprising floating a trap of any one of (1) to (6) at a predetermined position on the water surface, recovering it after a predetermined period of time, and classifying and counting the arthropods present in the sticky area. [Explanation of symbols]

[0059] 10, 40...capture device 11, 41…Main unit 12, 42…Bottom 13, 43…Roof section 14, 44…Side 15...Adhesive layer 16, 46…Aperture 17, 47…Floating material 18, 48…Fixed cord 19, 49…Fixing members S…Adhesion field P…Pillar

Claims

1. a body having a hollow structure with a bottom, a roof and sides; The body has at least one opening in a side portion; The bottom portion has an adhesive area on an upper surface thereof to which an adhesive is applied; The bottom surface is provided with a floating material, The body and the float are made of a water-resistant material; The bottom surface is capable of floating on the water surface so that the top surface of the bottom is substantially horizontal. An arthropod trap for capturing arthropods that live on the water surface and in aquatic and wetland plants.

2. 2. The trap of claim 1, further comprising a water-resistant fastener having one end attached to the body or the flotation material.

3. 3. The trap according to claim 2, further comprising a waterproof fixing member at the other end of the fixing string, the fixing member being an O-ring or an S-hook, and capable of fixing the main body to a stake or a plant stem.

4. A trap according to any one of claims 1 to 3, wherein the height of the sides is between 0.5 and 10 cm.

5. A trap according to any one of claims 1 to 4, wherein an upper surface of the roof portion is approximately horizontal.

6. 6. The trap according to claim 1, further comprising at least two openings on the sides thereof, the openings being opposed to each other across the center of the body.

7. A trap according to any one of claims 1 to 6, wherein at least one opening in the side portion extends to the lower end of the side portion.

8. A trap according to any one of claims 1 to 7, wherein the arthropod is a spider.

9. 9. The trap of claim 8, wherein the spider is a wolf spider.

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