Arthropod trap and arthropod trapping 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 capturing arthropods such as spiders that live on the surface of water, and a method for capturing arthropods such as spiders that live on the surface of water. [Background technology]

[0002] Arthropods such as spiders and insects that inhabit rice paddies, especially wolf spiders, are known as natural enemies that prey on rice pests such as rice planthoppers and leafhoppers. Wolf spiders have high population densities in rice paddies and are highly effective at preying on them, making them promising for use in rice pest control. To effectively utilize these natural enemies for pest control, it is important to understand their occurrence in rice paddies. Traditionally, methods for assessing natural enemy occurrence have involved direct visual observation and counting of natural enemies on and near rice plants in rice paddies. However, this method requires instantaneous identification of the type of natural enemy, making it difficult for anyone other than experienced investigators to implement. Furthermore, due to the behavioral characteristics of natural enemies, visual observation and counting results can vary greatly depending on the weather and time of day, making highly accurate surveys difficult. Another method is to capture natural enemies by sucking them up using an engine blower, but this method has problems such as the cumbersome process of sucking them up and sorting the samples after suction, 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 to set up traps. This method involves setting traps in a predetermined location for a predetermined period of time, and then observing the captured pests. For example, by setting the predetermined period of time to several hours or days, the type and number of captured insects can be less affected by the time of day or weather. Furthermore, since the remaining insects in the traps are classified and counted, this method can be easily carried out by even non-expert investigators. As an example of a method using such traps, Non-Patent Document 1 discloses a method in which polystyrene foam blocks coated with an adhesive are floated on the surface of rice paddies, and the spiders captured are counted and observed. Furthermore, Non-Patent Document 2 discloses a method in which pitfall traps are floated on the surface of ponds to capture spiders living in them. [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 traps used in the method described in Non-Patent Document 1 have an exposed sticky surface, but wandering spiders, natural enemies of rice pests, have a behavioral characteristic of moving around in search of places to hide from predators such as birds, making it difficult to capture them efficiently on an exposed sticky surface. Furthermore, the method described in Non-Patent Document 2 has a cup-shaped trapping portion, which makes it suitable for installation in ponds with a certain degree of depth, but it 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 surface of rice paddies 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 inventors of the present invention have conducted extensive research and discovered that a sticky trap with a bottom coated with an adhesive and a roof covering it, which can float on the water surface, can 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 that live on the water surface and in aquatic and wetland 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 coated with adhesive, and a flotation material on the lower surface of the bottom, the body and the flotation 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, one end of which is attached to the main body or the floating material. (3) A trap as described in (2), which has a waterproof fixing member at the other end of the fixing string, and the fixing member is an O-ring or an S-shaped hook, and the main body can be fixed 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 according to any one of (1) to (5), having at least two openings on the side thereof, facing each other across the center of the body. (7) A trap according to 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) The 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. [Effects 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 surface of rice paddies and in aquatic and wetland plants in order to classify and count them. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view showing the appearance of an arthropod trap according to an embodiment of the present invention; [Figure 2] 2 is a cross-sectional view taken along the line AA' in FIG. [Figure 3] FIG. 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, showing the arthropod trap actually installed in a rice paddy. [Figure 5] 10 shows a photograph of the sticky area of ​​an arthropod trap after trapping arthropods in a rice paddy with another embodiment of the arthropod trap of the present invention. [Figure 6] 1 is a line graph showing the change in the number of wolf spiders observed using the arthropod survey method of the present invention and the conventional survey method. The trends in the occurrence of wolf spiders were almost the same for the two methods, but the number of observations using the survey method of the present invention was clearly higher. [Figure 7] 1 is a line graph showing the transition of the number of captures of various natural enemies of rice pests observed using the arthropod survey method of the present invention. Water striders are more prevalent in early summer before the rice plants grow, and wolf spiders are more prevalent from July to September when the rice plants are fully grown. [Figure 8] 1 is a graph showing the number of wolf spiders captured using an arthropod trap of the present invention and an arthropod trap of the present invention 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 an 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 complete spiders were 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 represent the average number of wolf spiders captured in two traps in each treatment area. Of the traps tested, the traps with higher roof heights captured more wolf spiders. DETAILED DESCRIPTION OF THE INVENTION

[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] As used herein, "arthropods" refers to animals belonging to the phylum Arthropoda, and includes insects, crustaceans, spiders, centipedes, etc. The arthropods that the arthropod trap of the present invention targets are arthropods that inhabit the water surface of rice paddies and other areas, and aquatic and wetland plants, particularly insects and spiders. Furthermore, these include spiders of the Lycosidae family, the Linyphiidae subfamily, and the Tetragnathidae family, which are natural enemies of rice paddy pests, as well as insects belonging to the aquatic Hemiptera, including the Water Grididae family, and the aquatic beetles, including the Staphylinidae and Dytiscidae families.

[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 investigate the habitat of natural enemies with greater accuracy.

[0013] In this specification, the up-down direction of an arthropod trap (hereinafter also referred to simply as "trap") refers to 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 lowest part of the trap body, the "roof" refers to the part that constitutes the top part of the trap body that exists above the bottom with a gap and covers all or part of the area above 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 components constituting the bottom 12, roof 13, and side 14. The bottom 12, roof 13, and side 14 are preferably constructed from thin plate-like components. Materials for forming such thin plate-like components include paper, plastic, rubber, metal, and wood. Since it is desirable to separate only the adhesive region from the other components for classification and counting of captured arthropods, a material that can be easily separated, particularly with scissors, is preferred. Furthermore, since the trap will be floated on the water surface for a predetermined period of time, a water-resistant material is preferred. Suitable materials for such a trap include paper (especially cardboard, etc.), synthetic paper (e.g., Yupo® paper), plastic (e.g., polypropylene, polyethylene, polyethylene terephthalate, polyvinyl chloride, etc.), and alternative plastics (e.g., LIMEX®). The thin plate-like components are preferably opaque, particularly those with low light transmittance, to prevent the trap's interior from being seen from above.

[0016] The bottom portion 12, roof portion 13, and side portion 14 may be formed by folding and assembling a single thin plate-like member, or may be formed as separate thin plate-like members and connected together. The bottom portion 12, roof portion 13, and side portion 14 are preferably assembled as a single member.

[0017] The height of the side portions 14 of the main body 11 is preferably 0.5 to 10 cm, particularly 2.0 to 6.0 cm, and even more preferably 2.0 to 5.0 cm. Because wolf spiders and the like prefer narrow, dark places, providing a roof portion has the advantage of making it easier for them to enter the adhesive area inside. However, if the height of the side portions is too low, problems may arise, such as it being difficult for wolf spiders and the like to enter and the roof portion easily becoming attached to the adhesive area. On the other hand, if the height of the side portions is too high, problems may arise, such as light easily entering through the opening and the device being more likely to tip over due to crosswinds, etc. Setting the side portions to the above heights makes it less likely for the device to tip over, allowing for more efficient capture.

[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 to facilitate arthropod entry. The shape and size of the openings 16 are not particularly limited, but the main body 11, side portion 14, and openings 16 can be easily formed by forming the main body into a rectangular tube with both ends open, as in the illustrated example, and using the open portions as the sides. Note that more openings 16 may be formed, but the total area of ​​the openings 16 is preferably 70% or less, particularly 50% or less, 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 of 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. As in the illustrated example, the adhesive may be applied directly to a member constituting the bottom 12, or, for example, the adhesive may be applied to a thin plate-like member separate from the bottom 12 and fixed to the upper surface of the bottom 12 with the adhesive facing upward. The adhesive region S is preferably located at least near the side opening 16, and more preferably located over the entire upper surface of the bottom 12. In the adhesive region S, the adhesive may be applied as a uniform layer over the entire region as in the illustrated example, or may 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 is adhesive at room temperature but not fluid or water-soluble at room temperature. The adhesive is not particularly limited as long as it meets the above requirements, but examples include natural rubber, synthetic rubber, ethylene-vinyl acetate copolymer, polyisobutylene, polybutene, atactic polypropylene, and other liquid polymers, as well as tackifying resins such as petroleum resins. These substances can be used alone, in the presence of an appropriate solvent, or without solvent, by heating, or by mixing and applying in a latex or emulsion state. In particular, combinations of styrene-butadiene block polymer and / or ethylene-vinyl acetate copolymer with a tackifying resin and a plasticizer, and combinations of polyisobutylene with liquid polybutene and atactic polypropylene are preferred due to their excellent adhesive properties and ease of use, such as being able to be heated and mixed in a solvent-free system and applied directly. 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 semicircular shape, or a square shape, as long as the lower surface of the bottom is approximately horizontal. The shape of the main body bottom is not particularly limited, but a rectangular shape is preferable in consideration of ease of assembly. The size of the main body 11 is also not particularly limited, but since it will be installed in a rice paddy where rice is planted, it is preferable that the size of the bottom be approximately 5 to 30 cm, and particularly approximately 7 to 20 cm.

[0022] Floating materials 17 are attached to the underside of the bottom 12 of the main body 11. The number, shape, and size of the floating materials 17 are not particularly limited as long as they can float the trap 10 while maintaining the bottom 12 of the main body 11 horizontal. If the bottom 12 tilts, there is a risk of the adhesive flowing. In particular, as shown in the example, by attaching the floating materials 17 in a flat plate shape so that they cover the entire underside of the bottom 12, the bottom 12 can be maintained horizontal. The structure of the floating materials 17 can be any structure commonly used for floating materials, such as a sealed hollow structure or a porous structure. The material of the floating materials 17 is not particularly limited as long as it can provide the floating materials with water resistance, buoyancy, and rigidity sufficient to maintain their shape on the water surface. However, a material that is easy to process is particularly preferred. Examples of such materials include polystyrene foam, EVA, polyethylene foam, and polyurethane foam. When the floating materials 17 are flat, the size of the bottom of the floating materials 17 is preferably the same as the bottom 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 the top surface of the bottom 12 of the main body 11 is positioned about 0.1 to 3 mm above the water surface when placed on the water surface.

[0023] The flotation material does not necessarily have to be formed as a separate member from the main body 11, as in the illustrated example. For example, the thin plate-like member forming 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 flotation material (not shown).

[0024] Since the capture of natural enemies is continuously carried out 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 a desired position on the main body 11, and the other end is fixed to the stake or the like. The fixing string 18 may also be attached to a floating material 17. There is no particular limitation on the length of the fixing string 18, but it is preferable that it be approximately 10 to 50 cm. There is no particular limitation on the material of the fixing string 18 as long as it is water-resistant, but a lightweight PP string or the like that is easy to process can be preferably used.

[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, clothespin, O-ring, S-hook, or the like can be used. An O-ring, particularly an openable O-ring (commonly 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] Figure 4 shows another embodiment of the trap of the present invention actually installed in a rice paddy. In the trap 40 of the embodiment shown in Figure 4, the main body 41 is formed in a generally rectangular tube shape with both ends open, and the bottom 42 is larger than the roof 43 and has 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, an adhesive area 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 string 48 and a fixing member 49 may also be provided. In the illustrated example, the fixing member 49 is attached so as to surround a support P installed in the rice paddy. Other aspects are the same as those of the embodiment shown in Figures 1 to 3.

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

[0028] <2. How to capture arthropods> The arthropod trapping method of the present invention (hereinafter also referred to simply as "trapping method") is characterized in that the trap described in <1. Arthropod trap> is floated at a predetermined position on the water surface and recovered after a predetermined period of time has passed. Note that, in the trapping method of the present invention, detailed conditions etc. 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" refers to the trap being located within a certain distance from a predetermined point on the water surface. More specifically, the trap being located within 10 to 50 cm, more preferably 20 to 40 cm, from the point.

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

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

[0032] (1) Steps for preparing the trap This is a step of preparing the trap described in <1. Arthropod Trap>. In preparing and creating 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 above the water surface. The location of installation is not limited as long as there is a water surface, and examples include rice paddies, waterways, rush fields, lotus root fields, ponds, and pools. A rice paddy is preferred. The means for floating the trap at the "predetermined position" is not particularly limited, but for example, one method can be to attach one end of a fixing string to the trap body and fix the other end of the fixing string to a stake or the like installed on the ground of the rice paddy. The floating trap is left untouched for a predetermined period of time, preferably 3 to 10 days, but it is preferable to periodically inspect it to ensure that it has not sunk due to wind and rain, or that the string has broken and fallen off the predetermined position.

[0034] (3) Retrieving the trap After a predetermined period of time has passed, the trap is retrieved, and 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 Methods> The arthropod survey method of the present invention (hereinafter also referred to simply as "survey method") is characterized in that the trap described in <1. Arthropod trap> is floated at a predetermined position on the water surface, recovered after a predetermined period of time, and the arthropods present in the adhesive 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) Steps for 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. Method for capturing arthropods>.

[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 adhesive area. In particular, if the trap body is made of paper or plastic, the roof can be easily opened with scissors. Furthermore, by simply separating the bottom from the other components with scissors, storage, observation, and photography become easier.

[0039] The classification and counting of captured arthropods can be performed visually, but can also be performed, for example, by image analysis using a computer. For example, image data of a photograph of the obtained adhesive region can be input and compared with a pre-configured image database of arthropods on a computer, and the name of the closest arthropod can be output. This matching can also 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 this 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. Sample storage is also easy. 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, and by capturing and observing them multiple times in the same location, such as a rice paddy, it is possible to investigate seasonal changes in the types and numbers of arthropods living in that area. Alternatively, by capturing and observing them in multiple locations at the same time, it is possible to investigate regional differences in the types and numbers of arthropods living in rice paddies. Compared to conventional methods, both methods are not affected by the level of skill of the investigator, and allow for simple and reliable surveys. [Example]

[0042] Example 1: Comparison with the conventional method (visual method) In the same rice paddy field, the number of wolf spiders identified using the trapping device of the present invention (trap method) was compared with the number of wolf spiders identified using the conventional visual observation method (spotting method).

[0043] (1) Trap 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 cockroach trap measured 187 mm x 88 mm at the bottom and 28 mm high at the sides. One end of a 350 mm long PP string was attached to the bottom of the cockroach trap using a stapler. A 30 mm diameter plastic O-ring (card ring) was attached to the other end of the PP string to complete the trap.

[0044] The completed traps were floated on the surface of the water in the rice paddies. A support pole 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 loops at the ends of the traps through the support pole. The traps were replaced every week. The survey continued for 13 weeks at 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. Counts were conducted 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 of wolf spiders were almost the same for both 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 more accurate surveys were possible.

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

[0049] <Example 2: Test I to confirm the effectiveness of the trap roof> A trap was created in the same manner as in Example 1. As a comparative example, the roof and sides were cut off from the trap to create a trap without a roof, 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 wolf spiders captured 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 traps with roofs as in traps without roofs.

[0051] <Example 3: Test II to confirm the effectiveness of the trap roof> Using the same method as in Example 2, we created traps with and without roofs. We floated both traps in the same paddy field. After one week, we retrieved both traps and observed the number of wolf spiders captured and the condition of each individual.

[0052] Wolf spiders captured in both roofed and unroofed traps were classified according to the condition of the individuals observed. Individuals in which only palps were observed were classified as Group I, individuals in which parts of the individual were observed were classified as Group II, and individuals in which complete individuals were observed were classified as Group III. The proportion of each group among all wolf spiders observed was then calculated.

[0053] Figure 9 shows the proportion of each group among wolf spiders captured in covered and uncovered traps. Many clearly intact individuals were observed in the covered traps. This demonstrates that using covered traps makes it possible to obtain specimens in good condition.

[0054] <Example 4: Examination of trap roof height> A 0.2 mm thick plastic paper (manufactured by Tamiya Co., Ltd.) was folded to create a rectangular tubular member measuring 187 mm in length, 88 mm in width, and 1.5 cm in height, with 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 also prepared. The entire bottom portion of the cockroach trap used in Example 1, including the adhesive area, was cut out along with the backing and stapled to the surface of the plastic paper that corresponded to the top of the bottom before assembly, with the adhesive area facing upward. The plastic paper was then folded and secured with clips to form a rectangular tube. A 2 mm thick polystyrene foam board was cut to a size of 181 x 86 mm and attached to the bottom of the rectangular tubular member using a stapler. One end of a 350 mm long PP string was attached to the bottom using a stapler. A 30 mm diameter plastic O-ring was attached to the other end of the PP string to complete the various traps. Two traps each with heights of 1.5 cm, 3.0 cm, 4.0 cm, and 6.0 cm were made.

[0055] Each completed trap was floated on the water surface of the rice paddy. A support pole measuring 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 trap through the support pole. Two traps of each height condition were set up and left floating for one week during the same period (August 12th to 19th). 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. 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 height, 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 rice pests in rice farming, and can be used in industrial fields such as agriculture. They can also be used to investigate living things 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 to which 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 trap 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 according to any one of (1) to (4), further comprising a fixing 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. (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 body 12, 42…Bottom 13, 43...Roof section 14, 44...Side 15...Adhesive layer 16, 46…Aperture 17, 47...Floating material 18, 48...Fixed string 19, 49...Fixing members S… Adhesive domain 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 thereof; An adhesive area on the top surface of the bottom portion is provided with an adhesive; A floating material is provided on the underside of the bottom, The body and the float are made of a water-resistant material, It is capable of floating on the water surface so that the upper 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. 10. The trap of claim 1, further comprising a waterproof securing cord having one end attached to the body or the flotation material.

3. 3. The trap according to claim 2, wherein the other end of the fixing string is provided with a waterproof fixing member, the fixing member being an O-ring or an S-hook, and the main body can be fixed to a stake or a plant stem.

4. 4. The trap of claim 1, wherein the height of the sides is between 0.5 and 10 cm.

5. 5. The trap according to claim 1, wherein the upper surface of the roof portion is substantially horizontal.

6. 6. The trap according to claim 1, wherein the trap has at least two openings on the side 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 extends to the lower end of the side.

8. The trap of 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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