A pesticide composition for controlling tobacco thrips

Abstract

This invention belongs to the field of pesticide technology, specifically relating to a pesticide composition for controlling tobacco thrips. The active ingredient of this pesticide composition is a compound of thymol and propylene glycol alginate, or a compound of thymol and azadirachtin. When thymol is compounded with propylene glycol alginate or azadirachtin, it exhibits high activity against tobacco thrips within a certain mass ratio range, demonstrating a synergistic effect and higher control efficacy compared to a single active ingredient. Furthermore, this pesticide composition is composed of two components with different insecticidal mechanisms, which can delay the development of pesticide resistance in tobacco thrips, resulting in a low risk of resistance and extending the time between pesticide updates. Secondly, thymol, propylene glycol alginate, and azadirachtin in this pesticide composition are all biopesticide components, making them environmentally friendly and safe.

Description

Technical Field

[0001] This invention belongs to the field of pesticide technology, specifically relating to a pesticide composition for controlling tobacco thrips. Background Technology

[0002] Tobacco thrips, also known as onion thrips or cotton thrips, belong to the genus *Thrips* in the family Thripidae of the order Thysanoptera. They are a global pest, hosting over 300 species of plants, including important economic crops such as tobacco, leeks, garlic, onions, melons, tomatoes, and cotton. Tobacco thrips cause both direct and indirect damage. Direct damage primarily involves adults and nymphs using their rasping-sucking mouthparts to scratch the leaf surface, sucking out cellular contents and reducing photosynthesis, thus leading to yield reduction. Indirect damage mainly involves the transmission of plant viral diseases, causing epidemics and outbreaks, resulting in severe crop losses.

[0003] Currently, chemical pesticides still dominate the control of tobacco thrips. However, in tobacco production, long-term use of single-component pesticides to control tobacco pests easily leads to pesticide resistance, resulting in reduced pesticide efficacy. It has been reported that tobacco thrips have developed varying degrees of resistance to organophosphates, pyrethroids, and antibiotics. Combining different pesticide components is a convenient method for developing new pesticides; however, not just any pesticide component can be combined, as combinations can exhibit three types of effects: antagonism, additive, and synergistic. Combinations exhibiting synergistic effects are more likely to improve control efficacy. The inventors discovered in laboratory experiments that thymol, when combined with propylene glycol alginate or azadirachtin within a certain mass ratio, exhibits a synergistic effect against tobacco thrips, which can be used to develop new, highly effective pesticides for tobacco thrips control. Currently, no reports on such combinations have been found.

[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 pesticide composition for controlling tobacco thrips, which has high efficacy, low risk of resistance, and is green and safe.

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

[0007] A pesticide composition for controlling tobacco thrips, wherein the active ingredient is a compound of thymol and propylene glycol alginate, or a compound of thymol and azadirachtin.

[0008] Preferably, the mass ratio of thymol to propylene glycol alginate is 1-8:16-1.

[0009] Preferably, the mass ratio of thymol to propylene glycol alginate is 4:1.

[0010] Preferably, the mass ratio of thymol to azadirachtin is 1-20:2-1.

[0011] The present invention also provides an insecticide comprising the aforementioned pesticide composition for controlling tobacco thrips.

[0012] The present invention also provides the application of the pesticide composition for controlling tobacco thrips in the control of tobacco pests.

[0013] Preferably, the tobacco pests include tobacco thrips.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] (1) High efficacy. When thymol of the present invention is combined with propylene glycol alginate or azadirachtin, it exhibits high activity against tobacco thrips within a certain mass ratio range, showing a synergistic effect. Compared with single active ingredients, it has a higher control effect.

[0016] (2) Low risk of resistance. The pesticide composition of the present invention is composed of two components with different insecticidal mechanisms, which can delay the development of resistance in tobacco thrips, resulting in low risk of resistance and extending the time for pesticide replacement.

[0017] (3) Green and safe. The pesticide composition of the present invention contains thymol, propylene glycol alginate and azadirachtin, which are all biological pesticide components, environmentally friendly and green and safe. Detailed Implementation

[0018] 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.

[0019] Example Indoor bioactivity test of thymol compound

[0020] 1. Test reagents

[0021] 98% thymol (Shanghai Aladdin Biochemical Technology Co., Ltd.), 98% propylene glycol alginate (Shanghai Yuanye Biotechnology Co., Ltd.), 95% azadirachtin (Shanghai Yuanye Biotechnology Co., Ltd.).

[0022] 2. Test pests

[0023] Tobacco thrips were collected from the flue-cured tobacco growing area in Baise City, Guangxi Zhuang Autonomous Region. After being raised for eight generations in the laboratory of Guangxi University, second-instar nymphs with basically the same physiological state were selected as test insects.

[0024] 3. Test methods: (Refer to "NY / T 1154.6-2006 Guidelines for Indoor Bioassay of Pesticides - Part 6: Insecticidal Activity Test - Immersion Method").

[0025] The test agent was first dissolved in dimethyl sulfoxide, then diluted with a 0.1% Tween-80 aqueous solution to prepare a single-agent stock solution. Multiple formulations were set up, with seven mass concentration gradients for each single agent and each formulation mixture, using a proportional method. Each mass concentration solution was 50 mL. The test pests were immersed in the solution for 10 seconds, then removed, excess solution was absorbed with filter paper, and transferred to their original rearing conditions. Each treatment was replicated four times, with 25 insects immersed in each replicate. A treatment containing only 0.1% Tween-80 was included as a blank control. After 48 hours, the mortality of the test pests was investigated. The total number of insects and the number of dead insects in each treatment were recorded. The corrected mortality rate for each treatment was calculated, and regression analysis was performed using DPS software on the logarithmic values ​​of the agent concentration and the corrected mortality rate probability values ​​for each treatment to calculate the LC50 of each treatment. 50 .

[0026] 4. Pharmaceutical Evaluation

[0027] The co-toxicity coefficient (CTC value) of the mixture was calculated according to Sun Yunpei's method, and the combined effects were classified according to the following criteria: a CTC value ≥ 120 indicates a synergistic effect; a CTC value ≤ 80 indicates an antagonistic effect; and a CTC value < 80 < 120 indicates an additive effect. The experimental results are shown in Tables 1-3.

[0028] 5. Calculation Method

[0029]

[0030] In the above formula: P -- mortality rate, in %; K -- number of dead insects; N -- total number of insects treated.

[0031]

[0032] In the above formula: P1 -- corrected mortality rate, in %; P t --Treatment mortality rate, in %; P0--Control mortality rate, in %.

[0033]

[0034] In the above formula: ATI -- the measured toxicity index of the mixture; S -- the LC of the standard reagent. 50 Units are mg / L; M -- LC50 of the mixture50 The unit is mg / L.

[0035] TTI = TI A ×P A +TI B ×P B

[0036] In the above formula: TTI -- theoretical toxicological index of the mixture; TI A --Toxicity index of drug A; P A --Percentage content of drug A in the mixture, expressed as a percentage (%); TI B --Toxicity index of drug B; P B --The percentage content of drug B in the mixture, expressed as a percentage (%).

[0037]

[0038] In the above formula: CTC -- co-toxicity coefficient; ATI -- measured toxicity index of the mixture; TTI -- theoretical toxicity index of the mixture.

[0039] Table 1. Indoor bioactivity assay of thymol and propylene glycol alginate in thrips.

[0040]

[0041]

[0042] Table 1 shows that when thymol and propylene glycol alginate are combined, within a mass ratio range of 1-8:16-1, the co-toxicity coefficient of the combined formulation against tobacco thrips is between 80 and 120 at a mass ratio of 1:16, exhibiting an additive effect. The co-toxicity coefficients of the other combined formulations against tobacco thrips are all greater than 120, showing a synergistic effect, especially at a mass ratio of 4:1, where the synergistic effect is most significant. This indicates that the combination of thymol and propylene glycol alginate can improve the control effect against tobacco thrips.

[0043] Table 2. Indoor bioactivity assay of thymol and azadirachtin combination on thrips.

[0044] Drug Name and Proportion LC50 (mg / L) ATI TTI CTC thymol 143.4725 100.0000 -- -- azadirachtin 9.0863 1578.9981 -- -- Thymol 1: Azadirachtin 2 5.1063 2809.7154 1085.9987 258.7218 Thymol 1: Azadirachtin 1 9.2432 1552.1951 839.4990 184.8954 Thymol 4: Azadirachtin 1 18.3469 781.9986 395.7996 197.5744 Thymol 8: Azadirachtin 1 29.2638 490.2730 264.3331 185.4754 Thymol 16: Azadirachtin 1 43.1887 332.1992 186.9999 177.6467 Thymol 20: Azadirachtin 1 56.4587 254.1194 170.4285 149.1062

[0045] Table 2 shows that when thymol and azadirachtin are combined, within a mass ratio of 1-20:2-1, the co-toxicity coefficients against tobacco thrips for each combination are greater than 120, exhibiting a synergistic effect. This indicates that the combination of thymol and azadirachtin can improve the control effect against tobacco thrips.

[0046] In summary, when thymol is combined with propylene glycol alginate or azadirachtin within a certain mass ratio range, the co-toxicity coefficient is greater than 120, indicating a significant synergistic effect. Compared with single agents, this combination can improve the control effect against tobacco thrips.

[0047] 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 pesticide composition for controlling tobacco thrips, characterized in that, Its active ingredient is a compound of thymol and propylene glycol alginate, wherein the mass ratio of thymol to propylene glycol alginate is 1-8:12-1.

2. The pesticide composition for controlling tobacco thrips according to claim 1, characterized in that, The mass ratio of thymol to propylene glycol alginate is 4:

1.

3. An insecticide, characterized in that, The pesticide composition for controlling tobacco thrips as described in any one of claims 1-2.

4. The application of the pesticide composition for controlling tobacco thrips according to any one of claims 1-2 in the control of tobacco pests.

5. The application according to claim 4, characterized in that, The tobacco pests mentioned include tobacco thrips.

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