Rapid breeding method for wheat-bran-feed-free and drug-resistant predatory mites of mites

Abstract

The invention discloses a wheat-bran-free pellet feed for mites and a screening method of drug-resistant predatory mite strains. The feed for prey mites of predatory mites is creatively prepared into particles, wheat bran is not used, high-pressure sterilization does not need to be carried out on a feed matrix, and the problem that growth and propagation of mites are affected due to the fact that the wheat bran is prone to mildew and deterioration is solved. The feed is prepared into particles, gaps exist among the particles, the air permeability is good, mildewing can be avoided, mites can shuttle and crawl among the particles, and the death rate is greatly reduced. The granular wheat-bran-free feed is especially suitable for rapid propagation of prey mites, amplification of predatory mite populations and breeding research, and the survival rate is greatly improved. The screening method for the drug-resistant predatory mites is high in mite survival rate, easy to control experimental conditions, simple and convenient to operate, high in working efficiency, simple, convenient and rapid, and the breeding efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of biological pest control, and in particular to a mite bran-free feed and a method for rapid breeding of drug-resistant predatory mites. Background Art

[0002] Predatory mites are Arachnida, Acarina, and are a type of beneficial mite that specializes in preying on harmful mites, hence the name predatory mites. Predatory mites include the families Erythrodidae, Macroerythrodidae, Velvetidae, Longipalpidae, and Phytoseioidea. Predatory mites are an important type of natural enemy used in biological control, mainly used to control various mite pests such as red spiders on fruits and vegetables in fields and greenhouses. Predatory mites also prey on pests such as whiteflies and thrips in greenhouses. Because of their small size, fast development, large reproduction, strong predation ability, and similar ecological niches to harmful organisms, they can effectively control pests and mites. Therefore, predatory mites have become one of the important natural enemies of commercial production in the world, and are used to control pests in agricultural production.

[0003] The use of chemical pesticides to control pests and crop diseases is still a common method of pest control in agricultural production. However, the large-scale use of pesticides will cause a large number of predatory mites to die in the fields, making it impossible to achieve the purpose of using biological natural enemies to control pests. Resistant predatory mites are a type of predatory mite that has a high resistance to chemical pesticides. This resistance allows predatory mites to survive in an environment where chemical pesticides are used, thereby maintaining their effectiveness as a biological control method. The research and development and application of resistant predatory mites are aimed at solving the problem that traditional predatory mites are particularly sensitive to chemical agents. By improving the resistance of predatory mites, the contradiction between chemical control and biological control can be effectively coordinated, greatly improving the application effect of predatory mites.

[0004] In the research on indoor rearing of predatory mites and selection of drug-resistant strains, flour mites are usually raised as their prey. The population size and nutritional status of the prey (represented by the oval flour mite Aleuroglyphus ovatus) directly affect the growth rate and health of the predatory mite population. Therefore, in order to achieve rapid "marketing" (release) of predatory mites, shorten the growth cycle, and select excellent traits, high-quality rearing of their prey is particularly critical. In large-scale breeding factories such as breeding workshops, the feed used to feed oval flour mites is mainly sterilized wheat bran, supplemented with nutritional additives such as yeast protein. This method has low production costs and is easy to process and package. It is a natural enemy breeding operation mode preferred by predatory mite production companies. However, in small-scale breeding environments such as indoor breeding of resistant predatory mites, the wheat bran-based flour mite breeding model has more or less disadvantages. For example, 1. The oval flour mite has high requirements for environmental humidity (humidity required to be greater than 75%), and a dry environment will cause a large number of flour mites to die; and under conditions of high humidity, openness, wheat bran stacking, and poor air permeability, even if the wheat bran is sterilized, it will inevitably cause mildew and affect the flour mite population; 2. After yeast protein powder is added to wheat bran, it will quickly absorb moisture in the air, aggravate the mildew of wheat bran, and pollute the breeding environment; 3. In the process of breeding resistant predatory mites, mixing wheat bran with medicine or directly spraying pesticides into the breeding room will cause the predatory mite population to be flooded, the wheat bran to become damp and deteriorate, and the flour mite mortality rate is high. Summary of the invention

[0005] In view of the above technical problems currently existing in the art, the inventors of the present application have developed a bran-free flour mite feed formula based on the living habits of predatory mites and flour mites after years of experience accumulation, as well as a method for rapid breeding of drug-resistant predatory mites using the bran-free flour mite feed. Based on this, the present invention provides the following technical solutions:

[0006] The first aspect of the present invention provides a gluten-free granular feed for mites, which is obtained by attaching feed to solid particles using solid particles as carriers; the feed comprises the following components in parts by weight: 15 to 25 parts of yeast powder, 3 to 7 parts of starch, 0.2 to 0.8 parts of complex vitamins, and 0.7 to 1.3 parts of sucrose. Preferably, the feed also comprises 0.7 to 1.3 parts of a preservative.

[0007] The solid particles are selected from plastic particles, EVA sponge particles, volcanic stone particles, and silicon dioxide particles, and the particle size of the solid particles is 4-5 meshes; the plastic particles are selected from high molecular polymers, EVA, PP particles, etc., and the surface can be smooth or uneven;

[0008] The preservative is selected from one or more of sodium diacetate, propionic acid, sodium benzoate, and dehydroacetic acid;

[0009] The multivitamin is composed of the following components in parts by weight: 0.5-2 parts of 1 million IU biotin, 0.1-0.7 parts of 98% folic acid, 0.5-2 parts of 50% vitamin B2, 0.5-2 parts of 99% niacin, and 1-2 parts of 97% ascorbic acid;

[0010] The pellet feed is prepared by dissolving feed components in water to obtain a feed solution, immersing solid particles in the feed solution to allow the solid particles to adhere to / absorb the feed solution, taking out and drying the particles; the feed solution contains the following components in parts by weight: 15 to 25 parts of yeast powder, 3 to 7 parts of starch, 0.2 to 0.8 parts of complex vitamins, 0.7 to 1.3 parts of sucrose, and 40 to 60 parts of water.

[0011] The second aspect of the present invention provides a method for preparing the above-mentioned bran-free mite granular feed, comprising the following steps: preparing a feed solution, adding solid particles into the feed solution for immersion, taking out, and drying; preferably, the drying is to dry the surface moisture of the particles in an oven at 40-60°C.

[0012] The third aspect of the present invention provides another second type of gluten-free granular feed for mites, comprising the following components in parts by weight: 15 to 25 parts of yeast powder, 3 to 7 parts of starch, 0.2 to 0.8 parts of complex vitamins, 0.7 to 1.3 parts of sucrose, 4 to 6 parts of water, and 2 to 4 parts of magnesium stearate. Preferably, the feed also contains 0.7 to 1.3 parts of a preservative; the granular feed is prepared into granules by mixing all the components.

[0013] The second type of bran-free granular feed for mites mentioned above, wherein the granular feed is in the shape of a flake, a sphere, a cylinder, a cube, a polyhedron or an ellipsoid; preferably, the particle size of the granular feed is 0.3 to 0.7 cm, and more preferably, the granular feed is in the shape of a tablet with a diameter of 0.3 to 0.7 cm and a thickness of 0.2 to 0.3 cm;

[0014] The multivitamin is composed of the following components in parts by weight: the multivitamin is composed of the following components in parts by weight: 0.5 to 2 parts of 1 million IU biotin, 0.1 to 0.7 parts of 98% folic acid, 0.5 to 2 parts of 50% vitamin B2, 0.5 to 2 parts of 99% niacin, and 1 to 2 parts of 97% ascorbic acid.

[0015] The fourth aspect of the present invention provides a method for preparing the second type of bran-free mite granular feed, comprising the following steps: taking each component, mixing it, preparing the mixture into granules, and drying it; preferably, using a tablet press to press it into sheets.

[0016] The fifth aspect of the present invention provides a method for screening a pesticide-resistant predatory mite strain, comprising the following steps:

[0017] S1. Access to prey mites and predatory mites

[0018] The mite bran-free granular feed is put into an experimental bottle, and prey mites and predator mites are added, wherein the ratio of the prey mites to the predator mites is 10 to 50:1;

[0019] S2. Pesticide treatment

[0020] After the predatory mite population broke out, the pesticide was atomized and sprayed into the experimental bottles;

[0021] S3. Feeding after application

[0022] After spraying the mist, the surviving predatory mites are raised for 2 to 4 days, and then transferred to new experimental bottles containing prey mites for breeding; S4, multiple screening

[0023] After the predatory mite population recovers and breaks out again, steps S2-S3 are repeated multiple times, each time increasing the concentration of the pesticide in step S2. The surviving predatory mites are the resistant strains.

[0024] 8. The screening method according to claim 7, further comprising the following steps:

[0025] S5. Drug resistance assessment

[0026] The toxicity of the screened predatory mites is tested by using pesticides (i.e., the pesticides used in step S2), and the resistance multiples thereof compared with the sensitive strains are calculated to evaluate the resistance thereof;

[0027] The preferred method for evaluating pesticide resistance is: the steps S2-S4 are repeated 2-3 times to perform a toxicity test, and the LC values ​​of the surviving predatory mites to the pesticide are recorded. 50 The value was compared with the sensitive strains, and the resistance multiple was calculated to evaluate the resistance growth. The resistance multiple greater than 10 was a medium-resistant strain, and greater than 50 was a high-resistant strain. The calculation formula for the resistance multiple is:

[0028] Resistance multiple = LC of resistant strain 50 Value / LC of sensitive strains 50 value

[0029] In the above-mentioned screening method technical solution, the prey mite is selected from the oval powder-feeding mite;

[0030] The predatory mite is selected from Neoseiulus barkeri, Amblyseius nissi, and Neoseiulus cucumeris;

[0031] The breeding conditions are: 24-27°C and 65-75% humidity.

[0032] Preferably, the pesticide application device in step S3 is a compression atomizer, and the experimental bottle is a suction filter bottle; the pesticide liquid is poured into the atomizer cup, and then a plastic tube is used to sequentially connect the suction filter port on the side of the suction filter bottle, the atomizer cup, and the compression atomizer body, and the pesticide in the atomizer cup is atomized and sprayed into the suction filter bottle by the compression atomizer;

[0033] In step S1, 15 to 25 g of bran-free mite granular feed is added to a 500 ml experimental bottle, and 1,000 to 10,000 prey mites are inoculated; in step S3, the amount of pesticide used during application is 1.5 to 2.5 ml;

[0034] In step S4, after the predatory mite population recovers and breaks out again, steps S2-S3 are repeated multiple times, each time increasing the concentration of the pesticide in step S2 to 1.1 to 1.3 times the concentration of the pesticide used last time.

[0035] The beneficial effects of the present invention are:

[0036] The wheat bran-free feed of the present invention comprises yeast powder providing yeast protein and trace elements (such as selenium, iron, etc.), starch and sucrose providing carbon sources, and compound vitamins providing vitamin nutrition, thereby providing sufficient nutrition for the growth of prey mites. Magnesium stearate is a common lubricant, anti-adhesive agent, and flow aid in tablet processing, which allows the mixture used for tableting to have good fluidity and compressibility.

[0037] The present invention innovatively prepares the feed of predatory mites into granules, does not use wheat bran, and does not require high-pressure sterilization of the feed matrix, thereby avoiding the problem that wheat bran is easy to mold and deteriorate, thereby affecting the growth and expansion of mites. The feed is prepared into granules, with gaps between the particles, and good air permeability, which can avoid mildew. The mites can crawl and shuttle between the particles, greatly reducing the mortality rate. Granular wheat bran-free feed is particularly suitable for the rapid reproduction of prey mites, the expansion of predatory mite populations and breeding research, and greatly improves the survival rate.

[0038] The method for screening drug-resistant predatory mites of the present invention has high survival rate of mites, easy control of experimental conditions, simple operation, high work efficiency, simplicity and speed, and improves breeding efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is the device used in Example 3 for screening of pesticide-resistant predatory mite strains. DETAILED DESCRIPTION

[0040] The present invention will be further described below in conjunction with embodiments, but the present invention is not limited thereto.

[0041] The experimental methods in the following examples are conventional methods unless otherwise specified.

[0042] Sources of main reagents and materials:

[0043] Yeast powder: commercially available active dry yeast product;

[0044] The multivitamin tablet is composed of the following components in parts by weight: 1.0 part of 1 million IU biotin, 0.5 part of 98% folic acid, 1.0 part of 50% vitamin B2, 1.0 part of 99% niacin, and 1.0 part of 97% ascorbic acid.

[0045] Magnesium stearate: CAS No. 557-04-0, commercially available product;

[0046] Chlorpyrifos: also known as chlorpyrifos, CAS No. 2921-88-2, a commercially available product.

[0047] Example 1: Preparation of wheat bran-free feed for ellipsoidea acarid

[0048] 1. Formula A and processing technology of wheat bran-free feed for oval flour mites:

[0049] Prepare the gluten-free diet A for the oval powder mite according to the following steps:

[0050] (1) Take 20 g of yeast powder, 5 g of sweet potato starch, 0.5 g of multivitamin tablets, 1 g of sucrose, and 1 g of preservative sodium diacetate (C4H7NaO4), add 50 mL of pure water and stir evenly to obtain a feed solution.

[0051] (2) Add sterile solid particles with a diameter of 0.5 cm as a carrier (commercially available food-grade snowflake sand plastic particles are used) to the feed solution prepared in step (1) and soak until the surface of the solid particles adheres to the feed solution (add the particles to the feed solution, and then take them out after the surface of the particles adheres to the feed solution, without the need for long-term soaking). The solid particles can also be EVA sponge particles, volcanic stone particles, silica particles, etc.

[0052] (3) Spread the impregnated particles onto a tray lined with filter paper, and dry the surface moisture of the particles in an oven at 50°C overnight to obtain the obtained particles, which are then stored in a drying bottle for future use.

[0053] 2. Formula B and processing technology of wheat bran-free feed for ellipsoidal flour mites:

[0054] Prepare the gluten-free feed B for the oval powder mite according to the following steps:

[0055] (1) Take 20 g of yeast powder, 5 g of starch, 0.5 g of multivitamin tablets, 1 g of sucrose, and 1 g of preservative sodium diacetate, add 50 mL of pure water, and stir evenly to obtain a feed solution.

[0056] (2) Add 3 g of magnesium stearate and 5 g of pure water to the feed solution prepared in step (1), stir to form a flocculent feed, press the flocculent feed into tablets with a diameter of 0.5 cm and a thickness of 0.2-0.3 cm using a tablet press, and dry at 50° C. before use.

[0057] Example 2: Method for raising ellipsoidal powder-eating mites

[0058] Take 20g of the tablet bran-free feed B prepared in Example 1, put it into a 500ml suction filtration triangular bottle with a sterile filter paper at the bottom, access about 1000 oval powder-eating mites, seal the suction filtration port with a sealing film (tear off the sealing film to access the plastic tube during spraying treatment), plug the bottle mouth with a high-density sponge plug (high-density sponge can be breathable), put it in a constant temperature and humidity environment at 26°C and 75% humidity, and raise it in an incubator or on a tissue culture rack controlled by air conditioning. Regularly inject some sterile water on the filter paper at the bottom of the suction filtration triangular bottle to maintain humidity. After raising it for 10 days under the conditions of 26°C and 75% humidity, the powder mite population expanded by more than 3 times.

[0059] Example 3: Method for screening insecticide-resistant predatory mite strains

[0060] The method for screening insecticide-resistant predatory mite strains of the present invention is carried out according to the following steps, and the device used is as follows: Figure 1 shown.

[0061] S1. Raising oval flour mites

[0062] Take 20g of the granular bran-free feed A prepared in Example 1 and put it into a 500ml suction filtration triangular bottle with a sterile filter paper at the bottom, inoculate about 1000 adult elliptical powder-eating mites, seal the suction filtration port with a sealing film, and plug the bottle mouth with a high-density sponge plug, and place it in an incubator at 26°C and 75% humidity for constant temperature and humidity.

[0063] High-density sponges have a certain air permeability. Sterile filter paper is placed at the bottom of the suction filtration triangular bottle, and a syringe is used to connect a 0.2μm filter. A needle pierces the sponge and water is poured into the filter paper at the bottom of the bottle to ensure that the humidity in the bottle is greater than 70%. In addition, since pesticides are sprayed regularly after the predatory mites are connected, the humidity in the bottle can meet the humidity requirements of predatory mites and powder mites for a long time.

[0064] S2. Introducing predatory mites

[0065] After 10 days of feeding according to the above method, the population of flour mites in the triangular bottle reached about 10,000, and 1,000 adult Neoseius pasteurii mites were inoculated for expansion and reproduction, and the granules were raised at 26°C and 75% humidity. Compared with traditional feed wheat bran, the gaps in the granules are large and the air permeability is good, which is suitable for predatory mites to climb from the bottom to the top and find food. The activity space is large, the mortality rate is low, and the growth is rapid.

[0066] S3. Pesticide treatment

[0067] After about 10 days of feeding, the predatory mite population exploded (i.e., the powder mites were exhausted, and the predatory mite population was much larger than the powder mites; the dynamics of the powder mite and predatory mite populations were observed every day). Remove the sealing film on the filter port on the side of the triangular filter bottle, take 2 ml of the pesticide chlorpyrifos (the initial concentration is 0.2 g / L, and the survival rate of the predatory mites is gradually increased each time screening, and the pesticide concentration is increased by multiplying the pesticide concentration used this time by about 0.8, which is equal to the pesticide concentration used last time) and add it to the nebulizer cup. Use a plastic tube to connect the filter port on the side of the triangular filter bottle, the nebulizer cup, and the compression nebulizer body in sequence, and use the compression nebulizer to atomize the pesticide in the nebulizer cup and spray it into the triangular filter bottle.

[0068] S4. Feeding after application

[0069] After spraying the mist, the fish were raised at 26°C and 75% humidity for 3 days. Some predatory mites died, and the surviving predatory mites were transferred to new filter triangular bottles for continued breeding. The number of oval powder-eating mites added to the filter triangular bottles was approximately 10 to 50:1 for prey mites and predatory mites, and the fish were raised at 26°C and 75% humidity.

[0070] S5, multi-generation screening

[0071] After 10 to 15 days of feeding, when the predatory mite population recovers and breaks out again, steps S3-S4 are repeated. After a total of 10 times of pesticide treatment, the surviving predatory mites are removed for pesticide resistance assessment.

[0072] S6. Drug resistance assessment

[0073] This experiment was conducted to determine the toxicity of the pesticide chlorpyrifos to predatory mites (conventional toxicity determination techniques can be used).

[0074] In the preliminary experiment of lethal dose determination, the lethal dose of chlorpyrifos to predatory mites was determined by using existing technology: predatory mites that have not been screened for resistance were taken, and gradient concentrations of chlorpyrifos were set to be sprayed on the predatory mites in the bioassay device under the Potter spray tower. After 24 hours of treatment, the survival and death of the predatory mites were counted, and the lethal dose was calculated (after spraying and screening, the lethal dose of chlorpyrifos to predatory mites will gradually increase, and the lethal doses obtained from toxicity tests on different predatory mites are not the same).

[0075] The bioassay device designed and developed by this laboratory (see Chinese patent ZL202320287617.0, utility model name: a device for observing / feeding / bioassaying mites) was used to conduct indoor toxicity determination on predatory mites. The specific method is as follows: add an appropriate amount of clean water to the box of the device, apply urea hand cream (Shiseido, Japan, Barcode: 49325263) on the outer wall and top of the four bosses to prevent the predatory mites from escaping; use a handheld atmospheric sampler (QC-1B, Beijing Ke'an Instrument Co., Ltd.) to absorb 10-20 predatory mites into the hole nest on each boss (an appropriate amount of wheat bran and flour mites can be retained without affecting the count), and record the total number of predatory mites in each hole nest; after collecting the predatory mites, select 5-7 lethal doses of 25%-75% of the concentration gradient of the drug on the basis of the preliminary experiment. degrees, under a Potter spray tower (Burkard, UK), spray 2 mL of the drug mist evenly on the device, each device is repeated once, and the experiment is repeated at least three times; after the drug is evenly sprayed to the hole nest, cover the top of the device with a glass sealing sheet, and leave some air permeable gaps to ensure that the humidity in the experimental device is appropriate; the above device is transferred to a constant temperature and light incubator (27°C, L / D=16 / 8), and the number of deaths of predatory mites in each group is counted after 24 hours, with clean water as the control, and the mortality rate of the control group below 10% is considered to be an effective determination; toxicity data analysis is performed using PoloPlus software.

[0076] According to this method, the toxicity of the predatory mites that survived one spraying treatment (referred to as T1) and the predatory mites that survived 15 spraying treatments (referred to as T15) was determined. The results are shown in Table 1. It can be seen that the LC of the predatory mites obtained after 15 spraying screenings of the drug-resistant strain screening method of the present invention to chlorpyrifos is 50 It increased from 146.20 mg / L to 2342.15 mg / L, and drug resistance was greatly improved.

[0077] Table 1

[0078]

Claims

1. A bran-free granular feed for mites, characterized in that: The feed is obtained by attaching the feed onto the solid particles using solid particles as carriers; the feed comprises the following components in parts by weight: 15-25 parts of yeast powder, 3-7 parts of starch, 0.2-0.8 parts of complex vitamins, 0.7-1.3 parts of sucrose, and preferably the feed also comprises 0.7-1.3 parts of preservatives.

2. The wheat bran-free granular feed for mites according to claim 1, characterized in that: The solid particles are selected from plastic particles, EVA sponge particles, volcanic stone particles, and silicon dioxide particles, and the particle size of the solid particles is 4-5 meshes; the plastic particles are selected from high molecular polymers, EVA, PP particles, etc., and the surface can be smooth or uneven; The preservative is selected from one or more of sodium diacetate, propionic acid, sodium benzoate, and dehydroacetic acid; The multivitamin is composed of the following components in parts by weight: 0.5-2 parts of 1 million IU biotin, 0.1-0.7 parts of 98% folic acid, 0.5-2 parts of 50% vitamin B2, 0.5-2 parts of 99% niacin, and 1-2 parts of 97% ascorbic acid; The pellet feed is prepared by dissolving feed components in water to obtain a feed solution, immersing solid particles in the feed solution to allow the solid particles to adhere to / absorb the feed solution, taking out and drying the particles; the feed solution contains the following components in parts by weight: 15 to 25 parts of yeast powder, 3 to 7 parts of starch, 0.2 to 0.8 parts of complex vitamins, 0.7 to 1.3 parts of sucrose, and 40 to 60 parts of water.

3. The method for preparing the bran-free granular feed for mites according to claim 1 or 2, characterized in that: The method comprises the following steps: preparing a feed solution, adding solid particles into the feed solution for immersion, taking out, and drying. Preferably, the drying is to dry the surface moisture of the particles in an oven at 40-60°C.

4. A bran-free granular feed for mites, characterized in that: The feed comprises the following components in parts by weight: 15-25 parts of yeast powder, 3-7 parts of starch, 0.2-0.8 parts of complex vitamins, 0.7-1.3 parts of sucrose, 4-6 parts of water, and 2-4 parts of magnesium stearate. Preferably, the feed further comprises 0.7-1.3 parts of a preservative. The granular feed is prepared into granules by mixing all the components.

5. The bran-free granular feed for mites according to claim 4, characterized in that: The pellet feed is in the shape of a flake, a sphere, a cylinder, a cube, a polyhedron or an ellipsoid; preferably, the pellet feed has a particle size of 0.3 to 0.7 cm, and more preferably, a tablet with a diameter of 0.3 to 0.7 cm and a thickness of 0.2 to 0.3 cm; The multivitamin is composed of the following components in parts by weight: the multivitamin is composed of the following components in parts by weight: 0.5 to 2 parts of 1 million IU biotin, 0.1 to 0.7 parts of 98% folic acid, 0.5 to 2 parts of 50% vitamin B2, 0.5 to 2 parts of 99% niacin, and 1 to 2 parts of 97% ascorbic acid.

6. The method for preparing the bran-free granular feed for mites according to claim 4 or 5, characterized in that: The method comprises the following steps: taking each component, mixing it uniformly, preparing the mixture into granules, and drying it; preferably, a tablet press is used to press the mixture into tablets.

7. A method for screening insecticide-resistant predatory mite strains, characterized in that: The steps include: S1. Access to prey mites and predatory mites The mite bran-free granular feed according to claim 1 or 4 is placed in an experimental bottle, and prey mites and predator mites are added, wherein the ratio of the prey mites to the predator mites is 10 to 50:1; S2. Pesticide treatment After the predatory mite population broke out, the pesticide was atomized and sprayed into the experimental bottles; S3. Feeding after application After 2-4 days of feeding, the surviving predatory mites were transferred to new experimental bottles containing prey mites for feeding; S4. Multiple screening After the predatory mite population recovers and breaks out again, steps S2-S3 are repeated multiple times, each time increasing the concentration of the pesticide in step S2. The surviving predatory mites are the resistant strains.

8. The screening method according to claim 7, characterized in that The following steps are also included: S5. Drug resistance assessment The toxicity of the selected predatory mites was tested by using pesticides, and their resistance was calculated compared with the sensitive strains to evaluate their resistance. The preferred method for evaluating pesticide resistance is: the steps S2-S4 are repeated 2-3 times to perform a toxicity test, and the LC values ​​of the surviving predatory mites to the pesticide are recorded. 50 The value was compared with the sensitive strains, and the resistance multiple was calculated to evaluate the resistance growth. The resistance multiple greater than 10 was a medium-resistant strain, and greater than 50 was a high-resistant strain. The calculation formula for the resistance multiple is: Resistance multiple = LC of resistant strain 50 Value / LC of sensitive strains 50 value.

9. The screening method according to claim 7, characterized in that: The prey mite is selected from the group consisting of oval powder-eating mites; The predatory mite is selected from Neoseiulus barkeri, Amblyseius nissi, and Neoseiulus cucumeris; The breeding conditions are: 24-27°C and 65-75% humidity.

10. The screening method according to claim 7, characterized in that: In step S3, the pesticide application device is a compression atomizer, and the experimental bottle is a suction filter bottle; the pesticide liquid is poured into the atomizer cup, and then the suction filter port on the side of the suction filter bottle, the atomizer cup, and the compression atomizer body are connected in sequence with a plastic tube, and the pesticide in the atomizer cup is atomized and sprayed into the suction filter bottle by the compression atomizer; In step S1, 15 to 25 g of bran-free mite granular feed is added to a 500 ml experimental bottle, and 1,000 to 10,000 prey mites are inoculated; in step S3, the amount of pesticide used during application is 1.5 to 2.5 ml; In step S4, after the predatory mite population recovers and breaks out again, steps S2-S3 are repeated multiple times, each time increasing the concentration of the pesticide in step S2 to 1.1 to 1.3 times the concentration of the pesticide used last time.

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