Combined synergistic insecticidal composition for preventing and treating papaya thrips

Abstract

The invention belongs to the technical field of prevention and treatment of thrips, and particularly relates to a combined synergistic insecticidal composition for preventing and treating papaya thrips. The invention discloses a combined synergistic insecticidal composition for preventing and treating papaya thrips. Active ingredients of the combined synergistic insecticidal composition are formed by compounding wintergreen oil and guadipyr, the mass ratio of wintergreen oil to guadipyr is (1-30): (10-1). The components are reasonable, and after compounding, the activity is not simple superposition of the activities of all the components, but has a remarkable synergistic effect. Compared with a single agent, the insecticidal effect of the insecticidal composition can be improved, the problems existing when a single-component insecticide is used for preventing and treating papaya thrips can be effectively solved, and the insecticidal composition has important significance for developing a novel insecticide for preventing and treating papaya thrips.

Description

Technical Field

[0001] This invention belongs to the field of thrips control technology, specifically relating to a combined synergistic insecticidal composition for controlling papaya thrips. Background Technology

[0002] Thrips, belonging to the order Thysanoptera and family Thripidae, are a global pest and an important quarantine target. Thrips are tiny, concealed pests, and reproduce rapidly. They primarily damage host plants by sucking sap from young tissues with their rasping-sucking mouthparts and by laying eggs. The western flower thrips, *Frankliniella occidentalis* (Pergande), is a pest of papaya, mainly damaging flowers and young fruits. Initial symptoms are not obvious; however, as the fruit grows, the affected areas on the fruit surface develop into regular, slightly concave moss-like patches with rust-brown or silvery-brown scars. Mature fruits also develop black scars, severely affecting the fruit's appearance and quality.

[0003] Insecticides are the primary means of controlling thrips on papaya, such as abamectin, spirotetramat, spinosad, flupyrfuran, acetamiprid, and imidacloprid. In recent years, the unscientific use of insecticides, such as long-term, high-dose use of single-component insecticides, has led to the development of pesticide resistance in target pests, resulting in a gradual decrease in the control efficacy of existing chemical agents. Although increasing the dosage of insecticides can improve the control effect, this exacerbates the development of pesticide resistance and also raises issues of pesticide residues and environmental pollution. Therefore, developing novel insecticides for controlling papaya thrips is of great significance.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a combined synergistic insecticidal composition for controlling papaya thrips, so as to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A combined insecticidal composition for controlling papaya thrips, wherein the active ingredient of the combined insecticidal composition is a compound of wintergreen oil and spirotetramat, or a compound of wintergreen oil and pendimethalin; wherein the mass ratio of wintergreen oil to spirotetramat is 1-4:20-1; and the mass ratio of wintergreen oil to pendimethalin is 1-30:10-1.

[0008] Preferably, the wintergreen oil was purchased from Jiangxi Jingwang Natural Fragrance Co., Ltd., and its methyl salicylate content was 99%.

[0009] Preferably, the mass ratio of wintergreen oil to spirotetramat is 4:1.

[0010] Preferably, the mass ratio of wintergreen oil to pendimethalin is 1:7.

[0011] An insecticide comprising the aforementioned synergistic insecticidal composition, wherein the active ingredient comprises 0.25-65% by mass of the total mass of the insecticide, and the remainder comprises auxiliary ingredients.

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

[0013] The components of this invention are rationally formulated, and the combined activity is not a simple sum of the activities of the individual components, but rather exhibits a significant synergistic effect. Compared with single-agent formulations, it can improve the insecticidal effect and effectively solve the problems existing in the control of papaya thrips using single-component insecticides. This is of great significance for the development of novel insecticides for controlling papaya thrips. Detailed Implementation

[0014] The technical solution of this invention patent will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention.

[0015] Example Indoor bioactivity test

[0016] 1. Test reagents

[0017] Wintergreen oil (99% methyl salicylate content, Jiangxi Jingwang Natural Fragrance Co., Ltd.), 97% spirotetramat technical grade (Hebei Weiyuan Biochemical Co., Ltd.), 96% pendimethalin technical grade (Hefei Xingyu Chemical Co., Ltd.)

[0018] 2. Test pests

[0019] Western flower thrips collected from a papaya plantation were selected as test subjects after being raised for 12 generations in the laboratory and then selected thrips that had emerged 2 days prior.

[0020] Rearing conditions: Temperature 25℃, photoperiod 16L:8D, relative humidity 65±5%.

[0021] 3. Test methods: (Refer to NY / T 1154.6-2013 Guidelines for Indoor Bioassay Testing of Pesticides)

[0022] The test reagent was dissolved in a solvent and then mixed with 0.1% Tween-80 aqueous solution to prepare a single-agent stock solution with a concentration of 10000 mg / L. Then, multiple formulations were set up. Each single-agent stock solution and each formulation mixture was diluted with 0.1% Tween-80 aqueous solution to prepare 5 mass concentration gradients. Each mass concentration solution was 50 mL. All reagents were prepared and used immediately.

[0023] Petri dishes with a diameter of 9 cm were soaked in the pesticide solution for 1 hour, then removed and air-dried. Fresh, clean green bean pods (5 cm in length, grown in the laboratory, and untouched by any pesticides) were soaked in the pesticide solution for 30 seconds, removed, and air-dried. One pod per petri dish was then placed in a petri dish treated with the same pesticide solution. Twenty test pests were inoculated into each petri dish. The mouth of the petri dish was sealed with plastic wrap, and multiple ventilation holes were pricked in the plastic wrap with an insect pin to ensure airflow. The dishes were then transferred to their original rearing conditions for continued rearing. Each pesticide concentration was replicated four times, with a 0.1% Tween-80 aqueous solution used as a blank control. After 48 hours of treatment, insect mortality was assessed. The total number of insects and the number of dead insects were recorded for each treatment. The corrected mortality rate for each treatment was calculated. Regression analysis was performed on the logarithmic values ​​of the pesticide concentration and the corrected mortality rate probability values ​​for each treatment to calculate the LC50 of each treatment. 50 The co-toxicity coefficient (CTC value) of the mixture was calculated according to Sun Yunpei's method.

[0024] P1 = (K ÷ N) × 100, where P1: mortality rate; K: number of dead insects; N: total number of insects treated;

[0025] P2=[(P t -P0)÷(1-P0)]×100, where P2: corrected mortality rate; P t P0: Mortality rate under treatment; P0: Mortality rate in the blank control group;

[0026] Actual Toxicity Index (ATI) = (Standard reagent EC) 50 ÷ Test reagent EC 50 )×100;

[0027] Theoretical toxicity index (TTI) = Toxicity index of agent A × Percentage content of A in the mixture + Toxicity index of agent B × Percentage content of B in the mixture;

[0028] Co-toxicity coefficient (CTC) = [Actual toxicity index (ATI) of mixture ÷ Theoretical toxicity index (TTI) of mixture] × 100.

[0029] According to the criteria for classifying combined effects: a co-toxicity coefficient (CTC) ≥ 120 indicates a synergistic effect; a CTC ≤ 80 indicates an antagonistic effect; and 80 < CTC < 120 indicates an additive effect. The experimental results are shown in Table 1-2.

[0030] Table 1. Indoor bioactivity assay of wintergreen oil and spirotetramat combined with western flower thrips.

[0031] Drug Name and Proportion <![CDATA[LC 50 (mg / L)]]> ATI TTI CTC wintergreen oil 13.76 100.00 -- -- Spirotetramethrin 32.49 42.35 -- -- Wintergreen oil 1: Spirotetramethrin 20 16.19 84.99 45.10 188.46 Wintergreen oil 1: Spirotetramethrin 10 19.31 71.26 47.59 149.73 Wintergreen oil 1: Spirotetramethrin 8 22.88 60.14 48.76 123.35 Wintergreen oil 1: Spirotetramethrin 4 14.20 96.90 53.88 179.84 Wintergreen oil 1: Spirotetramethrin 2 11.34 121.34 61.57 197.08 Wintergreen oil 1: Spirotetramethrin 1 13.95 98.64 71.18 138.58 Wintergreen oil 2: Spirotetramethrin 1 7.66 179.63 80.78 222.36 Wintergreen oil 4: Spirotetramethrin 1 2.17 634.10 88.47 716.74

[0032] As shown in Table 1, the co-toxicity coefficients of wintergreen oil and spirotetramat in a mass ratio of 1-4:20-1 are all greater than 120, indicating that the combination of wintergreen oil and spirotetramat has a synergistic effect on the biological activity of western flower thrips.

[0033] Table 2. Indoor bioactivity assay of wintergreen oil and pendimethalin combination with western flower thrips.

[0034]

[0035]

[0036] As shown in Table 2, the co-toxicity coefficients of wintergreen oil and pendimethalin in a mass ratio of 1-30:10-1 are all greater than 120, indicating that the combination of wintergreen oil and pendimethalin has a synergistic effect on the biological activity of western flower thrips.

[0037] In summary, it can be seen that when the wintergreen oil of the present invention is compounded with spirotetramat or wintergreen oil with pendimethalin within a certain mass ratio range, the co-toxicity coefficient is higher than 120, which has a significant synergistic effect. Compared with single agents, it can improve the control effect on papaya thrips.

[0038] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A combined synergistic insecticidal composition for controlling papaya thrips, characterized in that, The active ingredient of the combined synergistic insecticidal composition is a compound of wintergreen oil and pendimethalin, wherein the mass ratio of wintergreen oil to pendimethalin is 1-30:10-1.

2. The synergistic insecticidal composition according to claim 1, characterized in that, The wintergreen oil was purchased from Jiangxi Jingwang Natural Fragrance Co., Ltd., and its methyl salicylate content is 99%.

3. The synergistic insecticidal composition according to claim 1, characterized in that, The mass ratio of wintergreen oil to pendimethalin is 1:

7.

4. An insecticide comprising the combined synergistic insecticidal composition according to any one of claims 1-3, characterized in that, In the insecticide, the active ingredient accounts for 0.25-65% of the total mass of the insecticide, and the remainder is auxiliary ingredients.

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