Miticidal composition and method and application thereof for regulating pesticide sensitivity of tetranychus urticae

Abstract

This invention relates to an acaricidal composition and its method and application for regulating the pesticide sensitivity of *Tetranychus spp.*, belonging to the field of pesticide technology. This invention provides an acaricidal composition comprising gossypol and bifenazate; the preferred mass ratio of gossypol to bifenazate is 1:9 to 9:1. This invention also provides a method for regulating the sensitivity of *Tetranychus spp.* to bifenazate, comprising applying the composition to *Tetranychus spp.* or its host plants. This invention further provides the application of the composition in controlling *Tetranychus spp.* and improving the sensitivity of *Tetranychus spp.* to bifenazate. This invention solves the problems of frequent resistance to bifenazate in *Tetranychus spp.* and decreased efficacy of single pesticides, improves the sensitivity of *Tetranychus spp.* to bifenazate, reduces the amount of chemical pesticides used, and achieves green and efficient control of *Tetranychus spp.* on different host plants.

Description

Technical Field

[0001] This invention belongs to the field of pesticide technology, specifically relating to acaricidal compositions and methods and applications for regulating the pesticide sensitivity of two-spotted spider mites. Background Technology

[0002] The two-spotted spider mite (Tetranychus urticae Koch) is a major global agricultural pest, hosting over 1100 plant species, including vegetables, fruit trees, cotton, and many other economic crops. This mite is characterized by its high reproductive rate, short generation cycle, wide host range, and tendency to develop pesticide resistance, often causing severe economic losses in production. Currently, chemical control remains the most common and effective method for controlling outbreaks of the two-spotted spider mite.

[0003] Bifenazate is a selective foliar spray acaricide with good efficacy against mites at all growth stages and no cross-resistance with other existing acaricides. It is widely used for controlling spider mites on fruit trees, cotton, and vegetables. However, long-term use has led to varying degrees of resistance in the two-spotted spider mite, with resistance levels significantly increased in some field populations. Therefore, finding ways to enhance the efficacy of bifenazate and delay the development of resistance is a pressing technical problem in this field.

[0004] Plant secondary metabolites play a crucial role in the defense against phytophagous pests. Gossypol, a sesquiterpene secondary metabolite unique to plants such as cotton, exhibits antifeedant, growth-inhibiting, or toxic activities against various pests and mites. When polyphagous pests feed on different host plants, the activity of their detoxification enzyme systems (such as cytochrome P450, carboxylesterase, and glutathione S-transferase) undergoes adaptive changes, thus affecting their sensitivity to chemical pesticides. Existing technologies include studies on the effects of sublethal concentrations of bifenazate on the detoxification enzyme system of the two-spotted spider mite, as well as reports on the combination of bifenazate with other chemical acaricides. However, there is currently no known technical solution for combining gossypol and bifenazate, and the potential synergistic value of combining gossypol with chemical acaricides has not yet been explored. Therefore, providing an acaricidal composition containing gossypol and bifenazate, and clarifying its synergistic effect and biological impact under different host plant conditions, is of significant practical importance for the scientific control of two-spotted spider mites. Summary of the Invention

[0005] The purpose of this invention is to provide an acaricidal composition and a method and application for regulating the sensitivity of two-spotted spider mites to pesticides, aiming to improve the sensitivity of two-spotted spider mites to bifenazate, achieve reduced dosage and increased efficacy of chemical pesticides, and delay the development of pesticide resistance.

[0006] On the one hand, the present invention provides an acaricidal composition, which adopts the following technical solution: Acaricide composition comprising gossypol and biphenylhydrazine.

[0007] Preferably, the mass ratio of gossypol to biphenylhydrazine is 1:9 to 9:1.

[0008] Preferably, it also contains a pesticide-acceptable carrier and / or adjuvant.

[0009] Preferably, the dosage form of the composition is any one of a suspension, wettable powder, water-dispersible granules, or emulsifiable concentrate.

[0010] On the one hand, the present invention also provides a method for regulating the drug sensitivity of two-spotted spider mites using the above-mentioned acaricidal composition, employing the following technical solution: A method for regulating the sensitivity of two-spotted spider mite to pesticides includes: applying the composition as described in any one of claims 1 to 5 to two-spotted spider mites or host plants fed on by two-spotted spider mites.

[0011] Preferably, the host plant is a legume, cucurbit, or solanaceous plant.

[0012] Preferably, the legume includes common bean; The Cucurbitaceae plants include cucumber; The Solanaceae family includes eggplant.

[0013] Furthermore, the present invention also provides the application of the above-mentioned acaricidal composition, employing the following technical solution: Application of acaricide composition in the control of two-spotted spider mites.

[0014] Preferably, the acaricide composition is used to enhance the sensitivity of Tetranychus bisporus to bifenazate, said application being to enhance the sensitivity of Tetranychus bisporus to bifenazate.

[0015] In summary, the present invention has the following beneficial technical effects: 1. This invention, by applying gossypol and bifenazate to the two-spotted spider mite or its host plant, can effectively regulate the sensitivity of the two-spotted spider mite to bifenazate, significantly improve the toxic activity of bifenazate against the two-spotted spider mite, thereby reducing the effective dosage of bifenazate, reducing the amount of chemical pesticides used, and reducing the risk of environmental residues.

[0016] 2. The regulation method provided by this invention can delay the development of resistance to bifenazate in Tetranychus tinctoria and extend the lifespan of bifenazate, providing a new technical means for the sustainable control of Tetranychus tinctoria. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0018] Example Example 1 A miticide composition for modulating the pesticide sensitivity of the two-spotted spider mite, comprising gossypol and bifenazate as active ingredients in a mass ratio of 1:9. Both gossypol and bifenazate have a purity of not less than 98%. The mixture of gossypol and bifenazate is homogeneously mixed to obtain a mixture, which is then formulated with a pesticide-acceptable carrier and / or adjuvants using conventional methods to produce a suspension concentrate, wettable powder, water-dispersible granules, or emulsifiable concentrate, thus yielding the miticide composition. When using, prepare the medicine solution as follows: S1. Preparation of Gossypol: Gossypol is insoluble in water. It can be dissolved in an organic solvent (such as dimethyl sulfoxide or acetone) to form a stock solution, and then diluted with water to the required concentration. S2. Preparation of bifenazate: If bifenazate is the technical grade, it should be dissolved in acetone or Tween or other adjuvants first, and then diluted with water to the required concentration; if bifenazate is a wettable powder, water-dispersible granule or emulsifiable concentrate, it can be directly diluted with water to the required concentration. S3. Mixing: Mix the gossypol solution obtained in step S1 with the biphenylhydrazine solution obtained in step S2 until homogeneous to obtain a usable acaricide composition solution.

[0019] Examples 2-5 The acaricide compositions prepared in Examples 2-5 differ from those in Example 1 in the mass ratio of hygroscopic phenol and bifenazate; all other steps are the same as in Example 1. The mass ratios of hygroscopic phenol and bifenazate in Examples 2-5 are shown in Table 1.

[0020] Table 1. Mass ratio of gossypol and bifenazate in the acaricide compositions prepared in Examples 2-5

[0021] Test case Experimental Example 1: Indoor toxicity determination of bifenazate mixed with fixed concentration of gossypol against two-spotted spider mite The indoor toxicity determination of bifenazate mixed with a fixed concentration of gossypol against Tetranychus bisporus includes the following steps: S1. Provide test insect sources Two-spotted spider mites were collected from the field and continuously reared for multiple generations in a laboratory artificial climate chamber with host plants (compared to legumes, cucumbers, and eggplants) at a temperature of 25±1℃, relative humidity of 65±5%, and photoperiod L:D=16h:8h. Healthy and consistent female adult mites were selected for testing.

[0022] S2. Methods for determining toxicity Using a spray method, a 1cm thick layer of sponge was placed in a 9cm diameter petri dish, followed by a layer of filter paper, and water was added to the height of the filter paper. Fresh host plant leaves were laid flat on the filter paper with the underside facing up, and the petioles were wrapped with moistened absorbent cotton. Using a fine brush, 30 adult female two-spotted spider mites, 2-4 days after emergence, were collected and inoculated onto the underside of the leaves.

[0023] 98% bifenazate technical and 98% gossypol technical were serially diluted with sterile water (0.1% Tween-80). Seven concentrations of bifenazate were prepared: 59.72 mg / L, 29.86 mg / L, 14.93 mg / L, 7.46 mg / L, 3.73 mg / L, 1.86 mg / L, and 0.93 mg / L; five concentrations of gossypol were prepared: 200 mg / L, 100 mg / L, 50 mg / L, 25 mg / L, and 12.5 mg / L. The compounding process involved diluting the gossypol technical to a fixed final concentration (25 mg / L or 50 mg / L) and then mixing it with an equal volume of the serially diluted bifenazate solutions to obtain a bifenazate solution containing a fixed concentration of gossypol. Application was performed using a Potter spray tower, with 1 mL sprayed each time. Water was used as a blank control, and each concentration was repeated four times. After application, place the mite in an artificial climate chamber. After 48 hours, check the number of dead mites under a stereomicroscope. Mites that cannot move when touched with the tip of a small brush are considered dead.

[0024] S3. The measurement results are shown in Tables 2 and 3.

[0025] Table 2. Toxicity test results of bifenazate alone and in combination with 25 mg / L and 50 mg / L gossypol against Tetranychus tataricus.

[0026] Table 3. Sublethal concentrations of bifenazate alone and in combination with 25 mg / L and 50 mg / L gossypol against Tetranychus tataricus.

[0027] The embodiments shown in this specification are only used to illustrate the technical solutions of the present invention and are intended to help those skilled in the art understand the principles and advantages of the present invention. They do not constitute a limitation on the scope of protection of the present invention. Although the present invention has been specifically described, those skilled in the art can still make any modifications, equivalent substitutions or other reasonable variations to the implementation methods without departing from the spirit and scope of the present invention. All equivalent technical solutions resulting therefrom should be considered within the scope of protection of this patent.

Claims

1. An acaricide composition, characterized in that, It contains gossypol and biphenylhydrazine.

2. The acaricide composition according to claim 1, characterized in that, The mass ratio of gossypol to biphenylhydrazine is 1:9 to 9:

1.

3. The acaricide composition according to claim 1, characterized in that, It also contains pesticide-acceptable carriers and / or adjuvants.

4. The acaricide composition according to claim 3, characterized in that, The composition is in the form of any one of a suspension, wettable powder, water-dispersible granules, or emulsifiable concentrate.

5. A method for regulating the sensitivity of two-spotted spider mite to pesticides, characterized in that, include: Apply the acaricide composition as described in any one of claims 1 to 4 to the two-spotted spider mite or the host plant that the two-spotted spider mite feeds on.

6. The method for regulating the sensitivity of two-spotted spider mite to pesticides according to claim 5, characterized in that, The host plant is a legume, cucurbit, or solanaceous plant.

7. The method for regulating the sensitivity of two-spotted spider mite to pesticides according to claim 6, characterized in that, The legumes mentioned include common beans; The Cucurbitaceae plants include cucumber; The Solanaceae family includes eggplant.

8. The use of the acaricidal composition according to any one of claims 1 to 4 in the control of two-spotted spider mites.

9. The application of the acaricide composition according to claim 8 in improving the sensitivity of the two-spotted spider mite to bifenazate, characterized in that, The application is to improve the sensitivity of Tetranychus tinctoria to biphenylhydrazine.

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