Biopesticide for preventing and treating tea lesser leafhopper

Abstract

The invention belongs to the technical field of biopesticides, and particularly relates to a biopesticide for preventing and treating tea lesser leafhopper, the active component of the biopesticide is formed by compounding metarhizium anisopliae and oxymatrine or tenvermectin; wherein the metarhizium anisopliae is a metarhizium anisopliae CQMa421 mother drug with a concentration of 15 billion spores per gram. According to the invention, the microbe source metarhizium anisopliae with insecticidal activity is reasonably compounded with other biopesticide components, and compared with the singly used source metarhizium anisopliae, the control effect on tea lesser leafhopper can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of biological pesticides, and particularly relates to a biological pesticide for preventing and controlling tea green leafhoppers. Background Art

[0002] The tea green leafhopper (Empoascaonukii Matsuda) is one of the most widespread, longest-lasting, and most damaging agricultural pests in my country's tea gardens. Its adults and nymphs primarily suck sap from young tea shoots, stunting the plants' growth. Infested shoots typically exhibit typical "leafhopper burn" symptoms, with yellowing of leaf margins, reddening of veins, and leaves becoming coarse, old, and curled. In severe cases, entire leaves may scorch and fall off easily, becoming brittle and affecting both yield and quality.

[0003] Insecticides such as bifenthrin, lambda-cyhalothrin, imidacloprid, cypermethrin, dinotefuran, and tolfenpyrad are the primary control agents for tea leafhoppers. However, the long-term and extensive use of single-action insecticides has led to significant resistance in tea leafhoppers. Furthermore, the extensive use of chemical pesticides can pollute the tea garden ecosystem. Compared to chemical pesticides, biopesticides are green, safe, and environmentally friendly, offering significant advantages in protecting ecological balance. Therefore, their use is crucial for the sustainable development of my country's tea industry.

[0004] Metarhizium anisopliae CQMa421 is a broad-spectrum insecticidal fungus that can be used to control tea green leafhoppers. However, single-ingredient insecticides have limited efficacy. Rational combinations of different active ingredients can further enhance control effectiveness. Therefore, it is necessary to screen for synergistic combinations of Metarhizium anisopliae CQMa421. Summary of the Invention

[0005] The purpose of the present invention is to provide a biological pesticide for preventing and controlling tea green leafhopper to solve the problem.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A biological pesticide for controlling tea green leafhoppers, wherein the active ingredient is a compound of Metarhizium anisopliae and oxymatrine or tianweimectin; wherein the Metarhizium anisopliae is the parent drug of Metarhizium anisopliae CQMa421 with 15 billion spores per gram.

[0008] Preferably, the composite mass ratio of Metarhizium anisopliae to oxymatrine is 1-9:9-1.

[0009] Preferably, the composite mass ratio of Metarhizium anisopliae to Tianweimectin is 1-15:6-1.

[0010] Preferably, the biological pesticide for controlling tea green leafhoppers further comprises auxiliary ingredients; in terms of mass percentage, the active ingredients account for 0.1-55% of the total mass of the biological pesticide for controlling tea green leafhoppers.

[0011] Preferably, the active ingredient accounts for 0.5-25% of the total weight of the biological pesticide for controlling tea green leafhopper.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] The present invention rationally compounds the microbial source Metarhizium anisopliae with insecticidal activity with other biological pesticide components. Compared with using Metarhizium anisopliae alone, the control effect of tea green leafhopper can be improved, and a method for biological control of tea green leafhopper can be provided. In addition, compared with chemical agents, the biological pesticide of the present invention has the advantages of being green and environmentally friendly, can overcome the problems existing in the use of chemical agents, and is of great significance to achieving the sustainable development of my country's tea industry. DETAILED DESCRIPTION

[0014] The following is a clear and complete description of the technical solution of the present invention. Obviously, the embodiments described are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of the present invention.

[0015] Example: Indoor biological activity test of Metarhizium anisopliae compound

[0016] 1. Test agent

[0017] Metarhizium anisopliae CQMa421 mother drug (15 billion spores / g, Chongqing Julixin Bioengineering Co., Ltd.), 99% matrine, 98% oxymatrine, 98% tembacin (the mass ratio of tembacin A to tembacin B is 8:2).

[0018] 2. Test pests

[0019] Tea green leafhoppers (Empoascaonukii Matsuda) were collected from tea trees in tea gardens and reared on fresh, pesticide-free tea shoots in the laboratory for six generations. Healthy third-instar nymphs of uniform size were selected as test pests.

[0020] Rearing conditions: 25±1℃, relative humidity 65±5%, light-dark cycle 16h / 8h.

[0021] 3. Test methods

[0022] The toxicity of each single agent and the mixture to the third instar nymphs of tea green leafhopper was determined by the insect immersion method, and then the joint action type of the mixture was evaluated.

[0023] Matrine, oxymatrine, and tianweimectin in the test agents were first dissolved in a solvent and then diluted with a 0.1% Tween-80 aqueous solution to prepare a single-dose stock solution; the spore suspension of Metarhizium anisopliae CQMa421 stock drug (100% by mass) prepared with a 0.1% Tween-80 aqueous solution was used as a single-dose stock solution; multiple groups of ratios were set up, and each single dose and each group of ratio mixtures were further diluted with a 0.1% Tween-80 aqueous solution to set 5 gradient mass concentrations. The above agents were prepared and used immediately;

[0024] Immerse the test insects in the solution for 10 seconds, then remove them. Remove excess solution with filter paper and transfer them to their original rearing conditions for continued rearing. Each treatment was replicated four times, with 25 insects immersed in each replicate. A solution containing only 0.1% Tween-80 was used as a blank control. After 48 hours, investigate insect mortality and calculate the adjusted mortality rate for each treatment.

[0025] 4. Evaluation of joint effects

[0026] Regression analysis was performed on the logarithmic values ​​of the pesticide concentrations and the corresponding corrected mortality probability values ​​to calculate the LC values ​​of each treatment pesticide on the test pests. 50 The Sun Yunpei method was used to calculate the co-toxicity coefficient (CTC value) of the mixture and evaluate the type of joint action: a co-toxicity coefficient (CTC) ≥ 120 indicates a synergistic effect; a co-toxicity coefficient (CTC) ≤ 80 indicates an antagonistic effect; and a co-toxicity coefficient (CTC) 80 < 120 indicates an additive effect. The results are shown in Table 1-2.

[0027] 5. Calculation method

[0028]

[0029] In the above formula: P is the mortality rate, in %; K is the number of dead insects; N is the total number of insects treated.

[0030]

[0031] In the above formula: P1--corrected mortality rate, unit is %; P t --Treatment mortality, unit is %; P0--blank control mortality, unit is %.

[0032]

[0033] In the above formula: ATI - the toxicity index of the mixture; S - the LC of the standard agent 50 , the unit is mg / L; M--LC of the mixture 50 , unit is mg / L.

[0034] TTI=TI A ×P A +TI B ×P B

[0035] In the above formula: TTI - theoretical toxicity index of mixture; TI A --Toxicity index of agent A; P A --The percentage of agent A in the mixture, expressed as percentage (%); TI B --Toxicity index of agent B; P B --The percentage of agent B in the mixture, in percentage (%).

[0036]

[0037] In the above formula: CTC - co-toxicity coefficient; ATI - measured toxicity index of mixture; TTI - theoretical toxicity index of mixture.

[0038] Table 1 Toxicity test results of Metarhizium anisopliae CQMa421 combined with matrine or oxymatrine to tea green leafhopper

[0039]

[0040] As shown in Table 1, the toxicity of matrine and oxymatrine against the tea green leafhopper was 13.685 mg / L and 16.407 mg / L, respectively. When Metarhizium anisopliae CQMa421 was binary compounded with matrine or oxymatrine at a mass ratio of 1-9:9-1, the cotoxicity coefficients of the combination of Metarhizium anisopliae CQMa421 and matrine against the tea green leafhopper ranged from 80 to 120, indicating an additive effect. The cotoxicity coefficients of the combination of Metarhizium anisopliae CQMa421 and oxymatrine against the tea green leafhopper were all greater than 120, indicating a synergistic effect.

[0041] Table 2 Toxicity test results of the complex of Metarhizium anisopliae CQMa421 and tianweimectin against tea green leafhopper

[0042]

[0043] As shown in Table 2, when Metarhizium anisopliae CQMa421 and tianweimectin were binary compounded at a mass ratio of 1-15:6-1, the co-toxicity coefficient of the compound combination to tea green leafhopper was greater than 120, showing a synergistic effect.

[0044] In summary, the present invention rationally compounds the insecticidal microbial source Metarhizium anisopliae with other biological pesticide components. Compared with using Metarhizium anisopliae alone, the control effect of tea green leafhopper can be improved, which can provide ideas for biological control of tea green leafhopper.

Claims

1. A biological pesticide for controlling tea green leafhopper, characterized in that: Its active ingredients are prepared by compounding Metarhizium anisopliae with oxymatrine or tianweimectin; wherein, the Metarhizium anisopliae is the parent drug of Metarhizium anisopliae CQMa421 with 15 billion spores / gram.

2. The biopesticide for controlling tea green leafhopper according to claim 1, characterized in that The composite mass ratio of Metarhizium anisopliae and oxymatrine is 1-9:9-1.

3. The biopesticide for controlling tea green leafhopper according to claim 1, characterized in that The composite mass ratio of Metarhizium anisopliae to Tianweimectin is 1-15:6-1.

4. The biopesticide for controlling tea green leafhopper according to claim 1, characterized in that The biological pesticide for controlling tea green leafhoppers further comprises auxiliary ingredients; in terms of mass percentage, the active ingredients account for 0.1-55% of the total mass of the biological pesticide for controlling tea green leafhoppers.

5. The biological pesticide for controlling tea green leafhopper according to claim 1, characterized in that The active ingredient accounts for 0.5-25% of the total weight of the biological pesticide for controlling tea green leafhopper.

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