Method for performing diamondback moth bioassay experiment by using artificial feed

Abstract

The invention provides a method for performing a bioassay experiment on plutella xylostella by using artificial feed, and belongs to the technical field of pesticides. The bioassay experiment method comprises the following steps: preparing an artificial feed; the method is actually used for operation steps of plutella xylostella. According to the experiment, after the artificial feed is prepared, the artificial feed is prepared into small blocks by a puncher, and the small blocks are put into a solution to be soaked, so that compared with a traditional bioassay experiment method, the effect that the plutella xylostella larvae eat actual soaked substances in a bioassay cup can be ensured, and the accuracy of the experiment is improved.

Description

Technical Field

[0001] This invention provides a method for conducting bioassays on diamondback moths using artificial feed, belonging to the field of pesticide technology. Background Technology

[0002] Diamondback moth (Plutella xylostella The diamondback moth, also known as the small green caterpillar, belongs to the order Lepidoptera and the family Pyrenidae. It causes immense damage to cruciferous vegetables and agricultural products worldwide. Due to its short reproduction rate and large population size, it can rapidly create pest infestations, profoundly impacting agriculture and causing significant losses to agricultural products. Because of its large affected area and prolonged duration, the diamondback moth has gradually replaced the cabbage white caterpillar as the number one pest of vegetables. Its short lifespan and large numbers pose a significant challenge to its control.

[0003] Currently, the main methods for controlling the diamondback moth include agricultural control, physical control, pesticide control, pheromone trapping, and sex mating techniques. However, due to cost considerations, farmers often use pesticide control, directly spraying pesticides onto the plant surface to minimize leaf damage. With the continued use of traditional pesticides, pests are gradually developing resistance. Furthermore, exposure to ultraviolet radiation degrades the insecticidal substances within traditional pesticides, significantly reducing their effectiveness. Additionally, the development of new pesticides takes a long time. Therefore, improving and protecting the insecticidal efficacy of pesticides is currently the most effective approach.

[0004] Current research shows significant differences in key parameters such as inoculation concentration (e.g., spore suspension concentration), inoculation method (leaf dipping or feeding), temperature and humidity control, insect instar, and mortality statistics. This fragmentation of the evaluation system makes it difficult to effectively compare and integrate research data from different laboratories or batches, failing to provide accurate and consistent evaluation criteria for the true efficacy and field application potential of biocontrol agents, and greatly increasing research and registration costs. Summary of the Invention

[0005] Compared to directly pouring feed into the test cup, adding the treatment liquid only covers the surface of the feed and may not completely cover it. Insects can easily burrow under the feed, preventing them from consuming the appropriate pesticides and resulting in inaccurate test results.

[0006] To solve the above problems, the present invention adopts the following technical solution: A method for conducting bioassays on diamondback moths using artificial feed includes the following steps: S1: Prepare diamondback moth feed according to the improved formula; S2: After the feed has cooled and solidified, use a punch to make small round pieces of the same size. S3: Take out the small round pieces from S2 and soak them in the solution prepared in advance for the biological test. After soaking for 20-30 minutes, take them out and let them air dry. S4: Use tweezers to hammer a crack into the surface of the test cup in advance to ensure air circulation. 6 hours in advance, use a brush to pick the diamondback moths into the test cup. Select 10 second- or third-instar diamondback moths for each test cup. S5: After drying, put the feed into the test cup, then put it into the incubator, and finally observe the mortality rate.

[0007] Furthermore, the method for preparing diamondback moth feed includes the following steps: Add 20 g of yeast powder and 6 g of agar powder to 250 mL of pure water, heat in an induction cooker, and boil three times to ensure that the agar powder is completely dissolved. Then quickly add it to a blender, along with 37.5 g of wheat germ powder, 1 g of sorbic acid, 1 g of methylparaben, 10 g of sucrose, 3 g of radish seeds, 0.5 g of vitamin D, 1 g of L-ascorbic acid, 1 mL of rapeseed oil, and 0.01 mL of linoleic acid. Start the blender twice. After the blending is complete, quickly dispense it into feed boxes and wait for it to solidify to obtain diamondback moth feed.

[0008] Furthermore, the volume of the solution prepared for biological testing should be at least 15 mL.

[0009] Furthermore, the incubator conditions in S5 were set as follows: temperature = 25±1℃, relative humidity = 75±5%, light / dark = 12h:12h.

[0010] Furthermore, all instruments used must be disinfected or sterilized in advance.

[0011] Advantages and benefits of the present invention: 1) Improve the accuracy of bioassay experiments.

[0012] 2) Using artificial feed can accelerate the reproductive cycle of diamondback moth.

[0013] 3) The bioassay experiment is relatively simple to operate and has high repeatability. Attached Figure Description

[0014] Figure 1 This is a flowchart of the bioassay experiment using the method of the present invention; Figure 2 A diagram showing the feed formulation using the method of this invention; Figure 3 This is a diagram illustrating the actual operation of the method of the present invention. Detailed Implementation

[0015] This invention provides a method for conducting bioassays on diamondback moths using artificial feed, comprising the following steps: S1: Prepare diamondback moth feed according to the improved formula, add it to the blender while it is still hot, pour in the other feed ingredients, and quickly pour it into the feed box after blending is complete. S2: After the feed has cooled and solidified, use a punch to make small round pieces of the same size. S3: Take out the small round pieces from S2 and soak them in the solution prepared in advance for the biological test. After soaking for 20-30 minutes, take them out and let them air dry. S4: Use tweezers to hammer a crack into the surface of the test cup in advance to ensure air circulation. 6 hours in advance, use a brush to pick the diamondback moths into the test cup. Select 10 second- or third-instar diamondback moths for each test cup. S5: After drying, put the feed into the test cup and observe the mortality rate.

[0016] Example 1: Preparation of Artificial Feed for Diamondback Moth Taking the preparation of 250 mL of feed as an example, first weigh out 20 g of yeast powder and 6 g of agar powder and place them in the same container. Simultaneously, weigh out 37.5 g of wheat germ powder, 1 g of sorbic acid, 1 g of methylparaben, 10 g of sucrose, 3 g of radish seeds, 0.5 g of vitamin D, and 1 g of L-ascorbic acid and place them in another container. Add the yeast powder and agar powder to 250 mL of pure water and heat in an induction cooker, bringing it to a boil three times to ensure the agar powder is completely dissolved. Then, quickly add this mixture to a high-speed blender, along with the other weighed ingredients, 1 mL of rapeseed oil, and 0.01 mL of linoleic acid. Run the blender twice. After the blending process is complete, quickly dispense the mixture into a large feed container and allow it to solidify to obtain the artificial feed. This feed can be used simultaneously as feed for biological testing experiments and as food for artificially incubated diamondback moths.

[0017] Example 2: Bioassay Experiment At least 6 hours in advance, select 2nd-3rd instar diamondback moth larvae and place them in a bioassay cup to remove any pre-existing feed and reduce experimental error. Use tweezers to create a crack in the surface of the bioassay cup to allow air circulation. Use a punch to divide the prepared feed into small round pieces. Prepare at least 15 mL of the solution to be tested, transfer it to a centrifuge tube, and immerse the small round pieces in the solution for 30 minutes. Then, use pre-sterilized tweezers to remove them, distinguishing them, and place them on clean paper towels to dry. Once the feed surface shows no shine or obvious moisture, transfer it to the bioassay cup and place it in an incubator. Set the incubator conditions to temperature = 25±1℃, relative humidity = 75±5%, and light / dark ratio = 12h:12h. Observe the number of dead diamondback moths after 24h and 48h and calculate the mortality rate.

[0018] Example 3: Incubation of the diamondback moth Place diamondback moth egg cards into a box, add half a portion of feed, place a clean paper towel on top, and then cover the box with the lid. Use a syringe to poke several small holes in the lid to allow for air circulation. Place the box in an incubator with the following conditions: temperature = 25±1℃, relative humidity = 75±5%, light / dark ratio = 12h:12h. Using this method, the time from egg to adult of the diamondback moth can be shortened to about 10 days, accelerating the growth cycle and ensuring sufficient reserves for large-scale testing experiments.

[0019] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A method for conducting bioassays on diamondback moths using artificial feed, characterized in that, Includes the following steps: S1: Prepare diamondback moth feed according to the formula; S2: After the feed has cooled and solidified, use a punch to make small round pieces of the same size. S3: Take out the small round pieces from S2 and soak them in the solution prepared in advance for the biological test. After soaking for a period of time, take them out and let them dry. S4: First, crack a hole in the surface of the raw test cup, and then use a brush to pick out the 2nd-3rd instar diamondback moth larvae into the raw test cup in advance; S5: After the feed has dried, put it into the test cup, then place it in the incubator, and finally observe the mortality rate.

2. The method according to claim 1, characterized in that, The method for preparing diamondback moth feed includes the following steps: Add 20 g of yeast powder and 6 g of agar powder to 250 mL of pure water, heat in an induction cooker, and boil three times to ensure that the agar powder is completely dissolved. Then quickly add it to a blender, along with 37.5 g of wheat germ powder, 1 g of sorbic acid, 1 g of methylparaben, 10 g of sucrose, 3 g of radish seeds, 0.5 g of vitamin D, 1 g of L-ascorbic acid, 1 mL of rapeseed oil, and 0.01 mL of linoleic acid. Run the blender twice. After the blending is complete, quickly dispense the mixture into feed boxes and wait for it to solidify to obtain diamondback moth feed.

3. The method according to claim 1, characterized in that, In S3, the feed is soaked in the solution for 20-30 minutes.

4. The method according to claim 1, characterized in that, The volume of the solution prepared for biological assay should be at least 15 mL.

5. The method according to claim 1, characterized in that, The incubator conditions in S5 are set as follows: temperature = 25±1℃, relative humidity = 75±5%, light / dark = 12h:12h.

6. The method according to claim 1, characterized in that, All utensils used must be disinfected or sterilized in advance.

7. The method according to claim 1, characterized in that, In S4, insect removal should be carried out at least 6 hours in advance.

8. Perform bioassay experiments according to any one of claims 1-7.

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