An insecticidal composition for controlling thrips of cowpea

Abstract

The present application belongs to the technical field of cowpea pest control, and particularly relates to an insecticidal composition for preventing and treating cowpea thrips. The present application finds through experiments that the LC 50 values of ethylicin, alginic acid propylene glycol ester and ethyl spinosyn single agent against cowpea thrips are 106.593 mg / L, 1.782 mg / L and 6.025 mg / L respectively. When ethylicin is compounded with alginic acid propylene glycol ester or ethyl spinosyn in a proper mass ratio, the LC 50 value of the compound combination against cowpea thrips is obviously lower than the LC 50 value of ethylicin. When the co-toxicity coefficient of the mixture is calculated by Sun Yunpei method, it is found that the co-toxicity coefficient of the compound combination is greater than 120, showing a synergistic effect, which helps to improve the control effect on cowpea thrips, delay the generation of drug resistance, and provide support for developing an insecticidal composition with significant synergistic effect and delayed drug resistance for preventing and treating cowpea thrips.

Description

Technical Field

[0001] This invention belongs to the field of cowpea pest control technology, specifically relating to an insecticidal composition for controlling cowpea thrips. Background Technology

[0002] Cowpea thrips are one of the most important pests of cowpeas, damaging the crop throughout its entire phenological period and causing losses of up to 80%. Reports indicate that the two main species of cowpea thrips are the bean thrips (Megalurothrips usitatus Bagnall) and the flower thrips (Frankliniella intonsa Trybom), both belonging to the family Thripidae in the order Thysanoptera. They not only damage cowpeas but also soybeans, peanuts, and other crops. Adult and nymph cowpea thrips use their rasping-sucking mouthparts to feed on the sap of young cowpea plants, damaging stems, leaves, flowers, and pods, thus affecting the yield and quality of cowpeas.

[0003] Cowpea thrips are small and difficult to detect when they cause damage. Nymphs and adults often hide in the overlapping areas of tender shoots, flower stamens, and petals, making them highly camouflage. Currently, chemical insecticides remain the main method for controlling cowpea thrips. However, due to years of high-frequency use, cowpea thrips have developed strong resistance to many chemical insecticides, resulting in less than ideal control effects. To address these issues, there is an urgent need to develop an insecticidal composition that significantly enhances efficacy and delays resistance development. By combining different compounds, highly effective control of cowpea thrips can be achieved.

[0004] Existing technologies disclose insecticidal compositions formulated with ethoxysulfuron and neonicotinoid insecticides such as thiamethoxam, thiamethoxam, acetamiprid, dinotefuran, or thiamethoxam. These compositions can be used to control rice planthoppers, aphids, whiteflies, scale insects, thrips, or rice gall midges. However, there are currently no reports on the use of ethoxysulfuron in combination with propylene glycol alginate or ethyl spinosad for the control of cowpea thrips. Summary of the Invention

[0005] The purpose of this invention is to provide an insecticidal composition for controlling cowpea thrips, in order to solve the problem that cowpea thrips have developed strong resistance to a variety of chemical insecticides due to high-frequency use over the years, resulting in unsatisfactory control effects.

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

[0007] An insecticidal composition comprising allicin and propylene glycol alginate or spinosad.

[0008] Preferably, the mass ratio of allicin to propylene glycol alginate is 5-9:5-1.

[0009] Preferably, the mass ratio of allicin to spinosad is 1-18:18-1.

[0010] According to the aforementioned insecticidal composition, this application also provides an insecticide, which is prepared by using the insecticidal composition as the active ingredient and supplementing it with auxiliary ingredients permitted in pesticide science.

[0011] Preferably, the insecticidal composition accounts for 0.1-65% of the total mass of the insecticide by weight percentage.

[0012] Furthermore, the insecticidal composition accounts for 0.75-45% of the total mass of the insecticide by weight percentage.

[0013] The present invention also provides the use of the insecticidal composition or the insecticide in controlling cowpea thrips.

[0014] Furthermore, the cowpea thrips includes the bean thrips.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] This invention, through experiments, discovered the LC50 of allicin, propylene glycol alginate, and ethyl spinosad as single agents against soybean thrips. 50 The concentrations were 106.593 mg / L, 1.782 mg / L, and 6.025 mg / L, respectively. When allicin was combined with propylene glycol alginate or ethyl spinosad in an appropriate mass ratio, the LC50 of the combined combination against soybean thrips was... 50 The value was significantly lower than that of ethoxylate. 50 Value. When calculating the co-toxicity coefficient of the mixture using Sun Yunpei's method, it was found that the co-toxicity coefficient of the compound combination was greater than 120, which showed a synergistic effect. This helps to improve the control effect on soybean thrips and delay the development of resistance. It can provide support for the development of insecticidal compositions that have significant synergistic effects and delay the development of resistance in cowpea thrips. Detailed Implementation

[0017] The technical solution of this invention patent will be clearly and completely described below. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0018] Example: Indoor bioactivity test of allicin compound

[0019] 1. Test reagents

[0020] 95% Ethyl Allicin Technical Grade (Nanyang Shensheng Agricultural Chemical Technology Co., Ltd.), 98% Propylene Alginate Technical Grade (Shanghai Yuanye Biotechnology Co., Ltd.), 81.2% Ethyl Sponsauce Technical Grade (Corteva Agricultural Technology Co., Ltd.)

[0021] 2. Test pests

[0022] Bean thrips were collected from cowpea fields and reared for five generations in an artificial climate chamber using fresh and clean cowpea pods. Adults with similar body size and physiological state were selected as test subjects.

[0023] 3. Test Methods

[0024] The leaf-tube film method was used. The test agent was dissolved in a suitable solvent and then diluted with a 0.1% Tween-80 aqueous solution to prepare a single-agent stock solution. Based on previous experimental results, multiple formulations were set up. Each single agent and each formulation mixture was then diluted with a 0.1% Tween-80 aqueous solution to create five mass concentration gradients. The solution was poured into 4mL centrifuge tubes, left to stand for 8 hours, then the solution was discarded and the tubes were allowed to dry. Several ventilation holes were made in the centrifuge tubes (the hole size was determined to prevent the tested pests from escaping).

[0025] Cut fresh, clean cowpea pods into 2cm segments, soak them in the pesticide solution for 10 seconds, remove them, air dry them, and place them into centrifuge tubes with the appropriate concentration of pesticide solution, one cowpea pod segment per tube. Inoculate 10 test pests into each centrifuge tube, cap the tubes, and place them in an artificial climate chamber at a temperature of 25±1℃ and a relative humidity of 65±5%. Each concentration was replicated 5 times, with each tube constituting one replicate. A 0.1% Tween-80 aqueous solution was included as a blank control.

[0026] After 48 hours, the mortality of the test insects was investigated. Insects that could not move when lightly touched with a brush tip were considered dead. The corrected mortality rate for each treatment was calculated. Regression analysis was performed using DPS software on the logarithmic values ​​of the pesticide concentrations and the corrected mortality rate probabilities for each treatment to calculate the LC50 of the pesticide for each treatment. 50 The co-toxicity coefficient (CTC value) of the mixture was calculated according to Sun Yunpei's method, and the synergistic effect of the pesticide was evaluated based on the calculated CTC value. The calculation method of the CTC value of the mixture refers to "NY / T1154.7-2006 Guidelines for Indoor Bioassay Tests of Pesticides - Insecticides - Part 7: Determination of Combined Effects of Mixtures".

[0027]

[0028] In the above formula: P -- mortality rate, in %; K -- number of dead insects; N -- total number of insects treated.

[0029]

[0030] In the above formula: P1 -- corrected mortality rate, in %; Pt -- Mortality rate, unit: %; P0 -- Mortality rate of blank control, unit: %.

[0031] 4. Evaluation of combined action of medicaments

[0032] Evaluation criteria: CTC ≥ 120 indicates synergistic effect; 80 < CTC < 120 indicates additive effect, and CTC ≤ 80 indicates antagonistic effect. The results are shown in Table 1-2.

[0033] Table 1 Indoor bioactivity determination results of the compounding of ethyl garlicin and propylene glycol alginate against Megalurothrips usitatus (48 h)

[0034]

[0035] As can be seen from Table 1, the LC 50 values of ethyl garlicin and propylene glycol alginate against Megalurothrips usitatus are 106.593 mg / L and 1.782 mg / L respectively. When ethyl garlicin and propylene glycol alginate are compounded within the mass ratio of 5-9:5-1, the LC 50 of the compounding combination against Megalurothrips usitatus is 2.674 - 12.895 mg / L. When calculating the co-toxicity coefficient of the mixed agent by Sun Yunpei method, it is found that the co-toxicity coefficient of the compounding combination is 120.120 - 162.183, which is greater than 120, showing a synergistic effect. This helps to improve the control effect against Megalurothrips usitatus and delay the generation of drug resistance.

[0036] Table 2 Indoor bioactivity determination results of the compounding of ethyl garlicin and spinetoram against Megalurothrips usitatus (48 h)

[0037]

[0038]

[0039] As can be seen from Table 2, the LC 50 values of ethyl garlicin and spinetoram against Megalurothrips usitatus are 106.593 mg / L and 6.025 mg / L respectively. When ethyl garlicin and spinetoram are compounded within the mass ratio of 1-18:18-1, the LC 50 of the compounding combination against Megalurothrips usitatus is 4.362 - 36.945 mg / L. When calculating the co-toxicity coefficient of the mixed agent by Sun Yunpei method, it is found that the co-toxicity coefficient of the compounding combination is 120.286 - 180.815, which is greater than 120, showing a synergistic effect. This helps to improve the control effect against Megalurothrips usitatus and delay the generation of drug resistance.

[0040] To sum up, the LC 50The concentrations were 106.593 mg / L, 1.782 mg / L, and 6.025 mg / L, respectively. When allicin was combined with propylene glycol alginate or ethyl spinosad in an appropriate mass ratio, the LC50 of the combined combination against soybean thrips was... 50 The value was significantly lower than that of ethoxylate. 50 Value. When calculating the co-toxicity coefficient of the mixture using Sun Yunpei's method, it was found that the co-toxicity coefficient of the compound combination was greater than 120, which showed a synergistic effect. This helps to improve the control effect on soybean thrips and delay the development of resistance. It can provide support for the development of insecticidal compositions that have significant synergistic effects and delay the development of resistance in cowpea thrips.

Claims

1. An insecticidal composition, characterized in that, The insecticidal composition is a compound of allicin and propylene glycol alginate; the mass ratio of allicin to propylene glycol alginate is 5-9:5-1.

2. An insecticide, characterized in that, The insecticide is prepared using the insecticidal composition of claim 1 as the active ingredient, supplemented with auxiliary ingredients permitted in pesticide science.

3. The insecticide according to claim 2, characterized in that, The insecticidal composition accounts for 0.1-65% of the total mass of the insecticide by weight percentage.

4. The insecticide according to claim 2, characterized in that, The insecticidal composition accounts for 0.75-45% of the total mass of the insecticide by weight percentage.

5. Use of the insecticidal composition of claim 1 or the insecticide of claim 2 in the control of bean thrips.

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