Insecticidal composition containing matrine and thiamethoxam

Abstract

The invention belongs to the technical field of agricultural insecticides, and relates to an insecticidal composition containing sophocarpidine and thiamethoxam. Effective components of the pesticide composition comprise sophocarpidine and thiamethoxam, and the two effective components are compounded. According to the invention, thiamethoxam and sophocarpidine are discovered and proposed as effective components of a pesticide preparation for compounding for the first time, so that a synergistic effect on aphid prevention and treatment is achieved, the influence of aphid damage on drug resistance of a traditional pesticide is reduced, and the comprehensive prevention and treatment effect on aphids is improved. Meanwhile, after compounding, the expected control effect is still achieved under the condition that the total dosage of the pesticide is reduced, so that the residue of the pesticide on crops is reduced, and the pollution to the environment is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of agricultural insecticides and relates to an insecticide composition containing matrine and thiamethoxam. Background Art

[0002] Aphids, also known as sticky insects or honey insects, belong to the order Hemiptera of the class Insecta of the phylum Arthropoda. There are nearly 5,000 known species of aphids in the world, and more than 1,000 species have been found in my country. Aphids have a wide range of hosts and usually reproduce in large numbers on crops, flowers and fruit trees, causing serious damage to agricultural production and horticulture. Aphids harm plants in both direct and indirect ways. On the one hand, aphids directly suck the juice of crops, affecting the normal absorption and transportation of nutrients, resulting in the growth of plants being hindered. On the other hand, aphids themselves may carry viruses, which spread the viruses while sucking the juice, and cause symptoms such as yellowing, curling leaves, mosaic deformities, and even plant death. At the same time, the honeydew excreted by aphids can form mucus on the leaves, which not only affects the photosynthesis of plants, but also attracts other pests, such as ants and whiteflies, aggravating crop damage.

[0003] Chemical control is a common method of controlling aphids, but long-term, large-scale application of a single type of chemical pesticide can easily cause aphids to develop resistance and increase the risk of environmental pollution. At present, the problem of aphid resistance is already very common. Summary of the invention

[0004] Aiming at the problem of drug resistance in the traditional aphid control process, the invention proposes a novel insecticide composition containing matrine and thiamethoxam.

[0005] In order to achieve the above object, the present invention is implemented by adopting the following technical solutions: An insecticide composition, whose active ingredients include matrine and thiamethoxam, and the two active ingredients are compounded.

[0006] Preferably, the mass ratio of thiamethoxam to matrine in the composition is 1:10-5:1.

[0007] Preferably, the mass ratio of thiamethoxam to matrine in the composition is 2:1-1:2.

[0008] Preferably, the mass ratio of thiamethoxam to matrine in the composition is 2:1.

[0009] The present invention proposes the use of the above composition in insecticides and fungicides.

[0010] The invention proposes the application of the composition in a pesticide preparation for preventing and controlling aphids.

[0011] Compared with the prior art, the advantages and positive effects of the present invention are: The present invention first discovered and proposed that thiamethoxam and matrine are compounded as active ingredients of pesticide preparations, which has a synergistic effect on the prevention and control of aphids, reduces the impact of aphid pests on traditional pesticide resistance, and improves the comprehensive prevention and control effect of aphids. At the same time, after compounding, the pesticide still achieves the expected prevention and control effect when the total dosage is reduced, thereby reducing the pesticide residues on crops and reducing the pollution to the environment. DETAILED DESCRIPTION

[0012] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described below in conjunction with specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0013] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways than those described herein. Therefore, the present invention is not limited to the specific embodiments of the following disclosure.

[0014] In the following examples, thiamethoxam technical (98.5%) was provided by Hebei Weiyuan Biochemical Pesticide Co., Ltd., and matrine technical (98%) was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. In the following examples, material ratios not otherwise specified are mass ratios, and material concentrations not otherwise specified are mass concentrations.

[0015] Example 1 1.1 Insect sources and methods The test insects were collected from cotton fields in the suburbs of Tai'an City, Shandong Province, and were identified as mainly cotton aphids Aphis gossypii Fresh cotton leaves were used for hydroponic propagation indoors. After one generation, wingless adult aphids with uniform body size were selected and tested for toxicity indoors by the immersion method.

[0016] 1.2 Test agents 98% thiamethoxam technical drug and 98% matrine technical drug were dissolved in dimethyl sulfoxide to prepare single-dose stock solutions with a concentration of 1000 mg / L, and then diluted into 7 series of concentrations (16, 8, 4, 2, 1, 0.5, and 0.25 mg / L) using an aqueous solution containing 0.05% Tween 80 by mass fraction.

[0017] 1.3 Experimental process 1.3.1 Matrine and thiamethoxam treatment alone Immerse fresh cotton leaves in the 16 mg / L thiamethoxam solution prepared in step 1.2 for 10 seconds, then dry them and place them in a culture dish with a 9 cm inner diameter and a moistened filter paper. Use a brush to pick up wingless adult aphids of basically the same size and body shape on the leaves and transfer them to an artificial climate chamber for breeding. Repeat the treatment 4 times under the same conditions, treating 20 heads each time. Replace the thiamethoxam solution of other concentrations and matrine solutions of different concentrations prepared in step 1.2, and treat them in the same way to obtain different experimental groups. And treat fresh cotton leaves with a 0.05% Tween 80 aqueous solution as a blank control. Check and record the death of the test insects 24 hours after treatment, and calculate the corrected mortality rate of each test group.

[0018] 1.3.2 Screening of synergistic combinations of matrine and thiamethoxam Based on the LC values ​​of matrine and thiamethoxam alone for cotton aphids determined in Experiment 1.3.1 50 , the corresponding single doses of thiamethoxam (2.36 mg / L) and matrine (5.52 mg / L) were prepared, and 9 mixed solutions with different mass ratios were prepared at the ratios of 1:1, 2:1, 3:1, 5:1, 10:1, 1:10, 1:5, 1:3, and 1:2. The insecticidal activity was tested by the leaf immersion method, and the corrected mortality of each mixed solution was calculated. The combination with a mortality rate higher than 50% and the highest lethality was the best combination.

[0019] 1.3.3 Data analysis and synergistic effect evaluation SPSS software was used to perform log-probit regression analysis on the adjusted mortality of each treatment, and LC 50 The co-toxicity coefficient (CTC) of compound drugs was calculated using the Sun Yunpei method.

[0020] First calculate the ATI of each single dose, the formula is: .

[0021] Among them, ATI is the actual toxicity coefficient of the mixture; S is the LC of each single dose 50 ; M is the LC of the mixture 50 .

[0022] Then calculate TTI, the formula is: .

[0023] Among them, TTI is the theoretical toxicity coefficient of the mixture; TI a is the LC of agent a (thiamethoxam) 50 , P a is the content of agent a in the mixture (%); TI b is the LC of agent b (matrine) 50 , P bis the content of agent b in the mixture (%).

[0024] The calculation formula of co-toxicity coefficient CTC is: .

[0025] Among them, CTC≤80 is antagonistic effect, 80<CTC<120 is additive effect, and CTC≥120 is synergistic effect.

[0026] 1.4 Results The toxicity test data of matrine and thiamethoxam single agent to cotton aphid are shown in Table 1.

[0027] Table 1 Toxicity results of matrine and thiamethoxam to cotton aphid The results of the toxicity test of matrine and thiamethoxam mixture to cotton aphids are shown in Table 2 below.

[0028] Table 2 The results of the toxicity test of matrine and thiamethoxam mixed to cotton aphid From the results in Table 2 above, it can be seen that within the mixing ratio range of 1:10-5:1, the combined toxicity of matrine and thiamethoxam is a synergistic effect (CTC>120). Among them, when the mixing ratio of thiamethoxam:matrine is 2:1, the co-toxicity coefficient can reach up to 357.2, and the synergistic effect is the most significant. The next is the 1:2 and 1:1 mixing groups, the co-toxicity coefficient can reach 313.2 and 311.8, and the synergistic effect is relatively high.

[0029] 1.5 Field trials 1.5.1 Test conditions The test site is located in Tai'an City, Shandong Province. The soil texture is sandy loam, the soil pH is 7.7, and the organic matter content is 2.3%. The test site has a cotton planting history of more than 10 years, and aphids occurred in the seedling stage. Cotton was sown on April 30, with a seed rate of 2.0 kg / mu, and covered with film after sowing. To prevent weeds, 33% pendimethalin EC was sprayed at 120 g / mu. No other pesticides were used during the test.

[0030] The cotton variety tested was Lumianyan 28, and artificial screening was performed before sowing to remove bad and shriveled seeds. Thiamethoxam:matrine mixed preparation groups with a ratio of 2:1, 1:1, and 1:2, thiamethoxam alone treatment group, and matrine alone treatment group were selected for field trials, with clear water application as the blank control, for a total of 6 treatment groups. The test spray volume was 450L / hm 2 The MATABI-16 backpack automatic sprayer was used to spray the pesticide evenly once, with the nozzle tilted downward to ensure that the front and back sides of the cotton leaves were evenly sprayed. This experiment adopted a completely randomized block design with a total of 6 treatment groups. Each treatment group had 4 repeated test plots, and the area of ​​each plot was 60m2 (6 m × 10 m), and 1.2 m wide protection rows are set between adjacent cells and around the test site.

[0031] 1.5.2 Preparation of medicine The field test pesticide treatments were: 21% thiamethoxam suspension (Shandong United Pesticide Industry Co., Ltd.), the dosage (active ingredient) was 12.85g / hm 2 ; 1% matrine aqueous solution (Hebei Zhongtian Bangzheng Biotechnology Co., Ltd.), dosage (active ingredient) is 10.15g / hm 2 Matrine and thiamethoxam mixture: weigh the single dose of the drug accurately according to the ratio requirements and the test plot dosage, stir and mix thoroughly, pour into the sprayer, and spray according to the test spray volume (450L / hm 2 ) Accurately calculate the amount of spray liquid required for the test plot, replenish the remaining water and then spray. The dosage for the plot (active ingredient) is set at 8.05g / hm 2 .

[0032] 1.5.3 Prevention effectiveness investigation Using the 5-point sampling method, 30 seedlings in the application area were inspected on the 1st, 3rd and 7th day after the application of the pesticide. Three young leaves were randomly selected from the top, middle and bottom of each plant to investigate the number of aphids and the number of dead aphids. Based on the following formula, the insect population reduction rate and control effect after different treatment times were calculated: , .

[0033] 1.5.4 Results and Analysis According to the field control effects of the pesticides in Table 3, one day after the application, the control effect of thiamethoxam and matrine in the ratio of 2:1 on aphids was 76.4%, which was significantly higher than that of the single treatment groups of thiamethoxam and matrine, and the application dosage was 8.05 g / hm 2 , which is less than the dosage of a single agent, indicating that the mixture of the two agents at a 2:1 ratio can effectively reduce the field application concentration of the agents while improving the control effect. Over time, the control efficacy of all treatment groups gradually increased. Three days after application, the control efficacy of all compound treatment groups was significantly higher than that of the single agent treatment group. Among them, the control efficacy of the compound treatment group with a ratio of 2:1 was significantly higher than that of the compound treatment groups with a ratio of 1:1 and 1:2, indicating that thiamethoxam and matrine can exert the best control effect under the condition of a mixed ratio of 2:1, and the results are consistent with the results of indoor toxicity determination. Seven days after application, the control efficacy of each treatment reached the highest, among which the control efficacy of the treatment group with a mixed ratio of 2:1 reached 87.1%, which was significantly higher than that of the compound treatment groups with a ratio of 1:1 and 1:2 (74.9% and 75.2%, respectively). Similarly, 7 days after application, the control efficacy of all compound treatment groups was significantly higher than that of the single agent treatment group.

[0034] Table 3 Field control effect of matrine and thiamethoxam mixed on cotton aphids Note: Different lowercase letters after the same column of data in Table 3 indicate significant statistical differences between the treatment groups ( P <0.05).

[0035] The above description is only a preferred embodiment of the present invention and does not limit the present invention in other forms. Any technician familiar with the profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes and apply it to other fields. However, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. An insecticidal composition, characterized in that: The active ingredients include matrine and thiamethoxam.

2. The insecticidal composition according to claim 1, characterized in that: The mass ratio of thiamethoxam to matrine in the composition is 1:10-5:

1.

3. The insecticidal composition according to claim 1, characterized in that: The mass ratio of thiamethoxam to matrine in the composition is 2:1-1:

2.

4. The insecticidal composition according to claim 1, characterized in that: The mass ratio of thiamethoxam to matrine in the composition is 2:

1.

5. Use of the composition according to any one of claims 1 to 4 in insecticides and fungicides.

6. Use of the composition according to any one of claims 1 to 4 in a pesticide formulation for controlling aphids.

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