JP7576329B2 - Arthropod trap and arthropod trapping method - Google Patents

Description

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.

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, and 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 is to capture predators by sucking them up with an engine blower, but this method has problems such as the cumbersome sucking and sorting of samples after sucking them up, and the spiders fleeing when the researcher approaches or when the engine blower makes noise, making it difficult to capture them efficiently.

Another method for investigating the occurrence of crop pests is to set traps. In this method, traps are set at a specified location for a specified time, and then the captured pests are observed. For example, by setting the specified 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, this method can be easily carried out even by non-expert investigators. As an example of such a method using traps, Non-Patent Document 1 discloses a method in which a block of polystyrene foam coated with a sticky substance is floated on the water surface of a paddy field, and the spiders captured are counted and observed. 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.

M. J. Oraze, et al., J. Arachnol., Vol.16: 331-337 (1988) A. K. Graham, et al., J. Arachnol., Vol.31: 78-89 (2003)

The traps used in the method shown in Non-Patent Document 1 have an exposed sticky surface, but wandering spiders, which are 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. In addition, the method shown in Non-Patent Document 2 has a cup-shaped trapping part, so it is suitable for installation in ponds and other areas with a certain degree of depth, but cannot be installed in shallow rice paddies.

The object of the present invention is to provide a trap and a trapping method that can efficiently capture arthropods that live on the water surface of rice paddies and other water bodies and in aquatic and wetland plants in order to classify and count them.

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 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 trap of 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) Any of the traps (1) to (4) further comprising a fixed string having one end attached to the main body or the float.
(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 according to 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 the trap after a predetermined period of time, and classifying and counting the arthropods present in the sticky area.

The present invention makes it possible to provide a trap and a trapping method that can efficiently capture arthropods that live on the water surface of rice paddies and other areas, and in aquatic and wetland plants, in order to classify and count them.

1 is a perspective view showing the appearance of an embodiment of an arthropod trap of the present invention; This is a cross-sectional view of A-A' in Figure 1. This is a cross-sectional view of B-B' in Figure 1. 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. 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. 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. 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. 1 is a graph showing the number of wolf spiders captured using the 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. 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 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 1 shows the number of wolf spiders captured using arthropod traps with different base-to-roof heights. The numbers in the figure 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.

＜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.

In this specification, "arthropods" refers to animals belonging to the phylum Arthropoda, including insects, crustaceans, spiders, centipedes, etc. The arthropods that are the subject of capture 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, 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, as well as aquatic Hemiptera including the family Water striders, and insects belonging to the family Aquatic Beetles including the family Staphylinidae and the family Dytisciidae.

In order to accurately investigate the habitat of natural enemies of rice pests in paddy fields, it is necessary to observe a larger number of natural enemies. The arthropod trap of the present invention efficiently captures the above arthropods, making it possible to observe many natural enemies and investigate the habitat of natural enemies with greater accuracy.

In this specification, the up-down direction of an arthropod trap (hereinafter also simply referred to as a "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.

One embodiment of the trap of the present invention is shown in Figures 1 to 3. Below, the trap of the present invention will be described based on the embodiment of Figures 1 to 3, but it is not intended that the trap of the present invention be limited to this embodiment. 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.

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 desirable 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 (especially cardboard, etc.), synthetic paper (Yupo (registered trademark) paper, etc.), plastic (especially 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 desirable for the thin plate-like member to be opaque, especially one with low light transmittance, so that the inside of the trap cannot be seen at least from above.

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

The height of the side parts 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. Wolf spiders and the like prefer narrow, dark places, so providing a roof part has the advantage of making it easier for them to enter the adhesive area inside. However, if the height of the side parts is made too low, problems may arise in that it is more difficult for the wolf spiders and the like to enter, and the roof part may easily adhere to the adhesive area. On the other hand, if the height of the side parts is made too high, problems may arise in that light is more likely to enter through the opening, and the spider may be more likely to tip over due to cross winds, etc. Setting the side parts to the above height makes it less likely for the spiders to tip over, and allows for more efficient capture.

At least one opening 16 is provided in the side 14 as an entrance for arthropods. Preferably, at least two openings 16 are provided in the side 14, facing each other across the center of the main body 11. The openings 16 preferably extend to the lower end of the side 14 so that arthropods can enter more easily. The shape and size of the openings 16 are not particularly limited, but the above-mentioned main body 11, side 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 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 14 in order to reduce water wetting of the adhesive area S or to keep the inside of the main body dark.

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 that constitutes 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 located at least near the side opening 16, and more preferably located on 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).

The "adhesive" applied to the adhesive region S refers to a non-drying substance that has adhesiveness at room temperature and is neither fluid nor water-soluble 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, tackifying resins such as petroleum resins, etc. These substances can be used alone, in the presence of an appropriate solvent, without 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 tackifying resin and plasticizer, and the combination of polyisobutylene with liquid polybutene and atactic polypropylene are suitable for use because they have good adhesive properties, can be mixed by heating in a solvent-free system, and can be applied as is, making them easy to work with. 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.

The shape of the main body 11 may be any shape, such as a trapezoid, inverted trapezoid, triangular, polygonal, semicircular, square, etc., in cross section, so long as the underside 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 rectangular shape is preferable. The size of the main body 11 is also not particularly limited, but since it will be installed in a rice paddy planted with rice, it is preferable that the size of the bottom be approximately 5 to 30 cm, and particularly 7 to 20 cm.

A floating material 17 is attached to the underside 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 attached in a flat plate shape so as to cover the entire underside of the bottom 12, so that the bottom 12 can be kept horizontal. As the structure of the floating material 17, any structure used as a normal floating material, such as a sealed hollow structure or a porous structure, can be adopted. The material of the floating material 17 is not particularly limited as long as it can give the floating material water resistance, buoyancy, and rigidity to the extent that it can maintain its shape on the water surface, but it is 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. It is preferable to adjust the buoyancy of the float 17 and the weight of the main body 11 so that when placed on the water surface, the top surface of the bottom 12 of the main body 11 is located approximately 0.1 to 3 mm above the water surface.

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 that constitutes the bottom 12 of the main body 11 can be made of a material with the desired buoyancy and rigidity, allowing the bottom 12 to function as a floating material (not shown).

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 a 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. There is no particular limit to the length of the fixing string 18, but it is preferable that it be about 10 to 50 cm. There is no particular limit to the material of the fixing string 18 as long as it is water resistant, but PP string, which is easy to process and lightweight, can be used preferably.

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, clothes peg, O-ring, S-hook, or the like can be used. An O-ring, particularly an openable O-ring (commonly known as a "card ring"), is preferably used, as it reduces the risk of the fixing string 18 wrapping around the stake or the trap tilting due to fluctuations in the water level in the rice paddy.

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 cord 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.

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

<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 collected 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.

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

The "predetermined period" refers to a period of time that is set in advance for installing the trap at a designated location, specifically 3 to 10 days, and more preferably 5 to 7 days.

More specifically, the capture method of the present invention comprises the following steps:
(1) Step of preparing a trap; (2) Step of placing the trap at a predetermined position on the water surface; and (3) Step of retrieving the trap.

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

(2) Step of placing 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 the trap is not limited as long as it is a place where there is a water surface, and examples thereof include rice paddies, waterways, rush fields, lotus fields, ponds and pools. A rice paddy is preferable. The means of 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 placed 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 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.

(3) Step of 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.

As described above, the capture method of the present invention is a very simple way to capture arthropods, particularly natural enemies of rice pests such as wolf spiders.

<3. Arthropod survey methods>
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, and after a predetermined period of time has passed, the trap is retrieved 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.

More specifically, the investigation method of the present invention comprises the following steps.
(1) Step of preparing a trap; (2) Step of placing the trap at a predetermined position on the water surface; (3) Step of retrieving the trap; (4) Step of classifying and counting arthropods present in the sticky area of the trap. Note that steps (1) to (3) are the same as those in <2. Method of capturing arthropods>.

(4) Classifying and counting arthropods present in the sticky area of the trap The roof of the retrieved trap is opened to expose the sticky area, allowing the trapped arthropods to be observed. 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 from the other parts with scissors or the like, storage, observation, and photography can be facilitated.

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 a photograph of the obtained sticky area may be input and compared with an image database of each arthropod pre-set in a computer, and the name of the closest arthropod may be output. This comparison may be performed using artificial intelligence (AI). When using AI, the image database may be used as training data to build an AI through machine learning using a known neural network, and this may be used to identify the corresponding arthropod from newly input image data.

Figure 5 shows a photograph of the sticky area of a 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, storing samples is also easy. In the example shown, 16 wolf spiders and 4 water striders can be identified.

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 that 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.

Example 1 Comparison with the conventional method (visual 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 (sight method).

(1) Trapping method A trap used in 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 for the bottom and 28 mm high for 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.

The completed trap was floated on the water surface of the rice paddy. A post 11 mm thick and 1,800 mm long 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 post. The trap was replaced every week. The survey continued for 13 weeks in the same location.

The arthropods captured using the trap 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.

(2) Visual counting method During the same period as the trapping method, the number of wolf spiders inhabiting random rice plants in the same paddy field was visually counted once a week.

(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 prevalence of wolf spiders were almost the same for the two methods. However, the number of observed spiders was clearly higher with the trap method. Observations using the trap method showed similar trends to those observed with the conventional method, and it was shown that the method allows for more accurate surveys.

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 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 with conventional methods.

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.

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.

Example 3: Trap roof effectiveness verification test 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.

Wolf spiders captured in traps with and without a roof were classified according to the condition of the individuals observed. The number of individuals in which only palps of wolf spiders were observed was classified as group I, the number of individuals in which parts of the individual were observed was classified as group II, and the number of individuals in which complete individuals were observed was classified as group III. The proportion of each group out of the total number of wolf spiders observed was then calculated.

Figure 9 shows the percentage of each group among wolf spiders captured in covered and uncovered traps. A large number of clearly intact individuals were observed in the covered traps. It became clear that using covered traps makes it possible to obtain specimens in good condition.

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.

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

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 made higher than a certain level.

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.

Reference Signs List 10, 40: Trap 11, 41: Main body 12, 42: Bottom 13, 43: Roof 14, 44: Side 15: Adhesive layer 16, 46: Opening 17, 47: Floating material 18, 48: Fixing string 19, 49: Fixing member S: Adhesive area P: Support

Claims (7)

A method for trapping arthropods using an arthropod trap, comprising:
The arthropod trap comprises:
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 method includes floating the arthropod trap at a predetermined location on the water surface and retrieving the trap after a predetermined period of time.
Methods for capturing arthropods. The method of claim 1, wherein the side height of the arthropod trap is between 0.5 and 10 cm. 3. The method of claim 1 or 2, wherein the arthropod trap has at least two openings on its sides, facing each other across the center of the body. The method according to any one of claims 1 to 3, wherein at least one opening in a side of the arthropod trap extends to a lower side edge. The method according to any one of claims 1 to 4, further comprising a fixed string attached at one end to the body or to a buoy . The method of claim 5 , wherein the arthropod trap comprises a fastening member at the other end of the fastening strap. A method for investigating arthropods using an arthropod trap, comprising:
The arthropod trap comprises:
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 method includes floating the arthropod trap at a predetermined position on the water surface, retrieving the trap after a predetermined period of time, and classifying and counting the arthropods present in the sticky area.
Methods for surveying arthropods.

Images