Insect larva olfactory behavior selection device and method

Abstract

The application provides an insect larva olfactory behavior selection device, and relates to the field of insect behavior, which comprises a square container, the square container is made of organic glass, three through holes are uniformly arranged in the middle of the bottom surface of the square container, the center points of the three through holes are connected to form an equilateral triangle, and the center of the square container and the center of the equilateral triangle are the same point; a cylindrical bait selection chamber is arranged at the through hole and penetrates through the bottom surface of the square container, and the top surface of the bait selection chamber is located on the upside of the bottom surface of the square container; filter paper is arranged in the inner cavity of the bait selection chamber, and the bottom surface of the square container at the outer circle of the bait selection chamber is marked as a trap area, the trap area is a circular area, and the trap area is coaxial with the corresponding through hole. The device can effectively solve the problems of low efficiency and low insect quantity in the determination of existing devices, and realizes batch, high-efficiency and accurate determination of insect olfactory behavior selection.

Description

Technical Field

[0001] This invention relates to the field of insect behavioral science, specifically to a device and method for selecting olfactory behaviors in insect larvae. Background Technology

[0002] Insect ethology, the science that studies the behavior of individual and collective insects, encompasses a wide range of insect behaviors, including how they find food, choose habitats, reproduce, interact with their own kind or other organisms, and respond to environmental changes. Research in insect ethology is of great significance for agricultural pest control (e.g., monitoring or trapping pests using light and pheromones), insect resource utilization (e.g., insect farming management or developing insect bioreactors), and ecosystem conservation. In the process of studying insect ethology, the direct perception and response of insects to specific odor stimuli is a key factor in understanding their behavioral selection mechanisms, providing effective technical support for pest forecasting and green control strategies.

[0003] Currently, devices used to study the selectivity of insect olfactory behavior include Y-shaped olfactometers, four-armed olfactometers, and wind tunnels. These devices can provide two, four, and one odor sources, respectively, which cannot meet the needs of insects to select for multiple odor sources at the same time. Furthermore, they can only measure one insect at a time, i.e., single-insect testing, resulting in a small number of insects being measured and low efficiency. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention aims to provide an insect larva olfactory behavior selection device. This device can effectively solve the problems of low insect quantity and low efficiency in existing devices, and achieve batch, high-efficiency, and accurate selective measurement of insect olfactory behavior.

[0005] Another objective of this invention is to provide a method for selecting olfactory behaviors in insect larvae, which helps insect larvae distinguish different odor sources and elicit corresponding behavioral responses. This method is convenient to operate and highly efficient.

[0006] The objective of this invention is achieved through the following technical solution: An olfactory behavior selection device for insect larvae includes a square container made of plexiglass with three through holes evenly distributed in the center of the bottom surface. The center points of the three through holes form an equilateral triangle, and the center of the square container and the center of the equilateral triangle are the same point. A cylindrical bait selection chamber is set at the through holes, penetrating the bottom surface of the square container. The top surface of the bait selection chamber is located on the upper side of the bottom surface of the square container (i.e., the top surface of the bait selection chamber protrudes towards the bottom surface of the container). Filter paper is placed in the inner cavity of the bait selection chamber, and a trap area is marked on the bottom surface of the square container outside the bait selection chamber. The trap area is a circular area and is coaxial with the corresponding through hole.

[0007] Based on further optimization of the above scheme, an insect release box is set at the center of the square container for placing insect larvae.

[0008] Based on further optimization of the above scheme, the inner radius of the bait selection chamber is 1.4cm and the depth is 4.5cm.

[0009] Based on further optimization of the above scheme, the height of the bait selection chamber protruding from the bottom surface of the square container is 0.4 to 1 cm.

[0010] Based on further optimization of the above scheme, the diameter of the filter paper is 2.5cm; the bait is selected from the inner cavity wall and the support blocks are evenly arranged around its own central axis to support the filter paper and facilitate the placement and removal of the filter paper.

[0011] Based on further optimization of the above scheme, the radius of the trap area is 3cm.

[0012] A method for selecting olfactory behaviors in insect larvae, employing the aforementioned selection device, comprising: Step S1: Select N healthy and active insect larvae and starve them for 30 minutes; after starvation, place the larvae in the release box in the center of a square container, with the release box upside down. Step S2: The three bait selection chambers are labeled as negative control group, experimental group and blank control group respectively. The filter paper of the negative control group is soaked in hexane solvent and then dried. The filter paper of the experimental group is soaked in hexane solvent and then dried before the odor bait is placed. The blank control group is not treated in any way. Step S3: Open the insect release box, release the insect larvae, observe the larvae's selectivity. If a larva stays in a trap area for more than 2 minutes, it is considered to have selected the corresponding filter paper scent. Record the number of larvae in each trap area. Step S4: Set up 5 biological replicates for each treatment; and after each test, clean the device with anhydrous ethanol and water and then air dry it to reduce odor residue; in addition, before each test, exchange the positions of the negative control group, experimental group and blank control group.

[0013] Based on further optimization of the above scheme, the number of insect larvae shall not be less than 10, that is, N≥10.

[0014] Based on further optimization of the above scheme, the negative control group and the blank control group can be replaced by other types of odor baits, and the filter paper odor baits need to be soaked in n-hexane solvent before use.

[0015] The following are the technical effects of the present invention: The device used in this invention has good compatibility, enabling testing of different odor baits and thus expanding the detection range. Furthermore, the device uses readily available and inexpensive raw materials and has a simple manufacturing process, allowing for rapid mass production and facilitating the selection of large numbers of insect larvae based on their olfactory behavior. In addition, the device can simultaneously measure the selective responses of multiple insect larvae to multiple odor sources, greatly improving testing efficiency and providing synchronous, real-time comparison, thereby ensuring the accuracy of test results and avoiding interference from environmental factors.

[0016] The device and method provided by this invention effectively help larvae distinguish different odor sources and elicit corresponding behavioral responses. The experimental method is simple, convenient to operate, time-saving, and highly efficient. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the selection device in an embodiment of the present invention.

[0018] Figure 2 This is a physical diagram of the selection device in an embodiment of the present invention.

[0019] Among them, 10 is a square container; 20 is a bait selection chamber; 30 is a filter paper sheet; and 40 is a trap area. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0021] Example 1: An insect larvae olfactory behavior selection device includes a square container 10, with an insect release box (i.e., ...) disposed at the center of the square container 10. Figure 1 The dotted area shown is used to place insect larvae. The square container 10 is made of plexiglass, and three through holes are evenly distributed in the center of its bottom surface. The line connecting the center points of the three through holes forms an equilateral triangle, and the center of the square container 10 and the center of the equilateral triangle are the same point (i.e., the distance from the center of the square container 10 to each through hole is consistent). A cylindrical bait selection chamber 20 is provided at each through hole, penetrating the bottom surface of the square container 10. The inner radius of the bait selection chamber 20 is 1.4 cm, and its depth is 4.5 cm. The top surface of the bait selection chamber 20 is located above the bottom surface of the square container 10 (i.e., the top surface of the bait selection chamber 20 protrudes towards the bottom surface of the container 10), and the height of the bait selection chamber 20 protruding from the bottom surface of the square container 10 is 0.4–1 cm (preferably 0.6 cm). Filter paper 30 is placed inside the bait selection chamber 20, and trap areas 40 are marked on the bottom surface of the square container 10 around the bait selection chamber 20 (e.g.,...). Figure 1As shown), the trap region 40 is a circular region and the trap region 40 is coaxial with the corresponding through hole.

[0022] The diameter of the filter paper 30 is 2.5cm; the inner wall of the bait selection chamber 20 is uniformly provided with support blocks around its own central axis, which are used to support the filter paper 30 and facilitate the placement and removal of the filter paper 30.

[0023] Example 2: In another preferred embodiment of the present invention, in order to avoid interference from external environmental factors and to ensure that the odor emitted by the filter paper 30 is effectively dispersed, a filter cover is movably installed on the top surface of the bait selection chamber 20.

[0024] Example 3: A method for selecting insect larvae based on their olfactory behavior, employing the selection device described in Example 1 or Example 2, taking moth larvae as an example, includes: Step S1: Select 10 healthy and active moth larvae and starve them for 30 minutes; after starvation, place the larvae in the release box in the center of a square container, with the release box upside down. Step S2: The three bait selection chambers are labeled as negative control group, experimental group and blank control group respectively. The filter paper of the negative control group is soaked in hexane solvent and then dried. The filter paper of the experimental group is soaked in hexane solvent and then dried before placing odor bait (host plant volatiles are used as odor bait in this embodiment). The blank control group is not treated in any way. Step S3: Open the insect release box, release the insect larvae, observe the larvae's selectivity. If a larva stays in a trap area for more than 2 minutes, it is considered to have selected the corresponding filter paper scent. Record the number of larvae in each trap area. Step S4: Set up 5 biological replicates for each treatment; and after each test, clean the device with anhydrous ethanol and water and then air dry it to reduce odor residue; in addition, before each test, exchange the positions of the negative control group, experimental group and blank control group. Finally, the behavioral responses of moth larvae to a single volatile substance are shown in Table 1 below: Table 1

[0025] Note: Data in the table are mean ± standard error. Different letters after the data in the same row indicate significant differences (P<0.05).

[0026] Table 1 clearly shows that, when comparing the selective behavioral responses of moth larvae to host plant volatiles, the response rate of the experimental group larvae to specific volatiles was 50% ± 3.16%, significantly higher than that of the blank control group and the negative control group. Furthermore, there was no significant difference in the selective response rate between the blank control and the negative control. This indicates that the device has strong specificity, accuracy, and feasibility in measuring the behavioral responses of host plant volatiles to moth larvae (such as the yellow-winged silkworm moth larvae).

[0027] Subsequently, the Y-type olfactometer could measure one insect and one treatment odor source, with 10 insects measured for each treatment odor source, i.e., one biological experiment; the four-arm olfactometer could measure one insect and three treatment odor sources, with 10 insects measured for each three treatment odor sources, i.e., one biological experiment. Five biological replicates were set up for each treatment, and the final results are shown in Table 2 below: Table 2

[0028] As can be clearly seen from Table 2, compared with other treatments, this embodiment requires 50 insects, 50 minutes, and 5 operations, indicating that this embodiment shortens the required time, reduces the number of operations, and greatly improves the experimental efficiency.

[0029] By comparing the selective behavioral responses of moth larvae to volatiles from a single host plant, it was found that the response rate of the experimental group to the specific volatiles was significantly higher than that of the blank control group and the negative control group, demonstrating that this method enhances the specificity, accuracy, and feasibility of measuring the behavioral responses of moth larvae. Comparing the selective behavioral responses of moth larvae to volatiles from three host plants, this embodiment shortens the required time, reduces the number of operations, and greatly improves experimental efficiency; it is clearly evident that compared to other devices and methods, this embodiment is more suitable as a method for olfactory behavioral selection in moth larvae.

[0030] In addition, in this embodiment, the negative control group and the blank control group can be replaced by other types of odor decoys, and the filter paper odor decoys need to be soaked in n-hexane solvent before use.

Claims

1. A device for selecting olfactory behaviors in insect larvae, characterized in that: The device includes a square container made of plexiglass, with three through holes evenly spaced in the center of the bottom surface. The center points of the three through holes form an equilateral triangle, and the center of the square container coincides with the center of the equilateral triangle. A cylindrical bait selection chamber is located at each through hole, penetrating the bottom surface of the square container. The top surface of the bait selection chamber is located on the upper side of the bottom surface of the square container. Filter paper is placed inside the bait selection chamber, and a trap area is marked on the bottom surface of the square container outside the bait selection chamber. The trap area is a circular area and is coaxial with the corresponding through hole.

2. The olfactory behavior selection device for insect larvae according to claim 1, characterized in that: An insect release box is set at the center of the square container for placing insect larvae.

3. The olfactory behavior selection device for insect larvae according to claim 1, characterized in that: The lure selection chamber has an inner radius of 1.4 cm and a depth of 4.5 cm.

4. The olfactory behavior selection device for insect larvae according to claim 1, characterized in that: The height of the bait selection chamber protruding from the bottom of the square container is 0.4 to 1 cm.

5. The olfactory behavior selection device for insect larvae according to claim 1, characterized in that: The diameter of the filter paper is 2.5cm; the bait is selected from the inner cavity wall and the support blocks are evenly arranged around its own central axis.

6. The olfactory behavior selection device for insect larvae according to claim 1, characterized in that: The radius of the trap area is 3 cm.

7. A method for selecting olfactory behaviors in insect larvae, employing a selection device as described in any one of claims 1 to 6, characterized in that: include: Step S1: Select N healthy and active insect larvae and starve them for 30 minutes; after starvation, place the larvae in the release box in the center of a square container, with the release box upside down. Step S2: The three bait selection chambers are labeled as negative control group, experimental group and blank control group respectively. The filter paper of the negative control group is soaked in hexane solvent and then dried. The filter paper of the experimental group is soaked in hexane solvent and then dried before the odor bait is placed. The blank control group is not treated in any way. Step S3: Open the insect release box, release the insect larvae, observe the larvae's selectivity. If a larva stays in a trap area for more than 2 minutes, it is considered to have selected the corresponding filter paper scent. Record the number of larvae in each trap area. Step S4: Set up 5 biological replicates for each treatment; and after each test, clean the device with anhydrous ethanol and water and then air dry it to reduce odor residue; in addition, before each test, exchange the positions of the negative control group, experimental group and blank control group.

Images