A biopesticide containing diafenthiuron and pyrethrin

Abstract

The application discloses a bio-pesticide containing bistrifluron and pyrethrin, and the bio-pesticide containing bistrifluron and pyrethrin can be effectively used for preventing and treating Bemisia tabaci.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of biological pest control, and particularly relates to a bio-compound insecticide containing bistrifluron and pyrethrin for synergistically controlling Bemisia tabaci. BACKGROUND

[0002] During the growth and development of crops, they are easily attacked by various pests, especially vegetable crops, which have various types of pests and serious damage, such as Bemisia tabaci, Plutella xylostella, Pieris rapae and the like. For a long time, chemical control is the main method for controlling crop pests, but long-term use of chemical insecticides causes pests to develop resistance, resulting in a decline in control effect, and frequent use of chemical pesticides also destroys the ecological environment and threatens human health. Compared with chemical insecticides, biological insecticides are often effective only on one or a few pests, and have the disadvantage of a narrow insecticidal spectrum, so in actual production, in order to delay the development of pest resistance, expand the insecticidal spectrum and improve the efficacy, different biological insecticide varieties or mixtures of biological insecticide varieties and chemical insecticide varieties are often used to control pests. Whether the mixture of two pesticides has synergistic, antagonistic or additive effects can be determined by using a certain pest as a test object, measuring the toxicity of the two pesticides in the laboratory, screening the optimal ratio and calculating the co-toxicity coefficient. If the co-toxicity coefficient after compounding is greater than 100, it is synergistic. Synergistic compounds improve the actual control effect, reduce the amount of pesticide used, delay the development of pest resistance and expand the insecticidal spectrum, and thus become an important means of integrated pest control.

[0003] Bemisia tabaci (Gennadius) belongs to Hemiptera, Aleyrodidae, and is a worldwide distributed polyphagous pest. It has a wide host range, and currently known to damage more than 600 species of plants in 70 families, including Solanaceae, Leguminosae, Cruciferae and Euphorbiaceae, etc. The host plants include vegetables, fruit trees, flowers, tobacco and other economic crops. B. tabaci adults and nymphs aggregate on the back of host plant leaves to suck sap, causing the leaves to lose green and growth to be inhibited, affecting the normal development of the plant. In addition to direct damage by sucking, B. tabaci also secretes a large amount of honeydew on the leaf surface and fruit, causing soot disease, affecting the normal photosynthesis of the leaves. In addition, B. tabaci can transmit many plant viruses of Geminiviridae, Hytteroviridae and Potyviridae, causing viral diseases of plants, further causing indirect damage. At present, the main way to control B. tabaci is still chemical control, because B. tabaci has a large population, a short generation cycle, and people's unreasonable use of pesticides in the field. B. tabaci has gradually developed resistance to organochlorine, organophosphorus, pyrethroid, carbamate and other insecticides, and has become one of the main pests with serious resistance and difficult to control. In addition, the nymphal stage of B. tabaci is about 15 days at 25-28℃, and the morphological difference between adults and nymphs is large. Some insecticides have good effect on nymphs but not on adults, and have good effect on adults but not on nymphs. Therefore, the ideal complex insecticide is one that has synergistic activity on both nymphs and adults, or one that has synergistic activity on adults or nymphs but additive activity on the other.

[0004] Pyrethrum is an active ingredient with insecticidal effect isolated and extracted from Pyreyhrum cineriifoliun Trebr. It is composed of pyrethrins I, pyrethrins II, cinerin I, cinerin II, jasmolin I and jasmolin II, etc. It has good insecticidal effect and is not easy to develop resistance. In recent years, the stability of pyrethrum, especially its light stability, has been greatly developed. Moreover, pyrethrum can be obtained by planting, and its extraction process and use cause little environmental pollution, greatly promoting the application of pyrethrum in the control of agricultural pests, and becoming one of the safest and most effective natural insecticides in the world.

[0005] Afidopyropen is a new insecticide with a novel structure and mechanism of action developed by Meiji Seika Kaisha, Ltd. and Kitasato Institute. It interferes with the feeding and dehydration of insects, ultimately causing them to starve to death. The drug is the only biological insecticide that has no cross-resistance with existing insect control agents on the market. Afidopyropen can effectively control piercing-sucking and sucking mouthpart pests such as aphids, whiteflies and leafhoppers, and has the characteristics of high efficiency, long persistence, low toxicity, short safety interval, low dosage, etc. It can be used to control pests that harm field crops and economic crops, and has little harm to beneficial organisms such as natural enemies and pollinating insects, and is suitable for resistance management and integrated pest management.

[0006] In order to solve the problems of narrow insecticidal spectrum, high price and slow efficacy of afidopyropen when used alone, the present application provides a mixed insecticide of afidopyropen and pyrethrin, which has a wider insecticidal spectrum and synergistic activity against Bemisia tabaci. SUMMARY

[0007] The technical problem to be solved by the present application is to provide a biological insecticide containing afidopyropen and pyrethrin to overcome the shortcomings of the prior art.

[0008] The technical problem to be solved by the present application is to provide a biological insecticide containing afidopyropen and pyrethrin to overcome the shortcomings of the prior art.

[0009] In order to solve the above technical problems, the present application discloses the following technical solutions:

[0010] In a first aspect, the present application discloses a composition comprising afidopyropen and pyrethrin.

[0011] Preferably, the mass ratio of afidopyropen to pyrethrin is 1:2.4-14, more preferably 1:3.2-12, and even more preferably 1:4-10, and in some embodiments, specifically 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5, 1:6, 1:6.5, 1:7, 1:7.5, 1:8, 1:8.5, 1:9, 1:9.5, 1:10, 1:10.5, 1:11, 1:11.5, 1:12, 1:12.5, 1:13, 1:13.5, 1:14, 1:14.5, 1:15, 1:15.5, or 1:16.

[0012] In a second aspect, the present application discloses the use of the composition of the first aspect in the preparation of an insecticide.

[0013] Preferably, the insecticide is an insecticide for controlling Bemisia tabaci.

[0014] The whitefly includes both whitefly nymphs and whitefly adults.

[0015] In a third aspect, the present application discloses an insecticide comprising the composition of the first aspect.

[0016] The insecticide is an insecticide for preventing and treating whitefly.

[0017] The whitefly includes both whitefly nymphs and whitefly adults.

[0018] Advantages:

[0019] The bio-compound insecticide containing bistrifluron and pyrethrin provided by the present application can be effectively used for preventing and treating whitefly, and can effectively prevent and treat both nymphs and adults. DETAILED DESCRIPTION

[0020] In the following examples, the experimental methods are conventional methods unless otherwise specified, and the reagents and materials can be obtained from commercial channels unless otherwise specified.

[0021] The bistrifluron and pyrethrin used in the present application can be directly purchased from the market. At present, there are many companies producing this drug on the market, and the source is wide. As long as the proportion range and application conditions described in the present application are met, it can be used.

[0022] The bio-compound insecticide provided by the present application is mixed by bistrifluron and pyrethrin. After the two are mixed, the insecticidal activity of the whitefly nymphs is synergized, the insecticidal effect is significantly improved, and the cost of the drug and the cost are reduced.

[0023] The following is a detailed description of the synergistic compound of bistrifluron and pyrethrin. These contents are only used for description and do not mean to limit the protection scope of the present application. The active ingredients described in the following are calculated by effective ingredients.

[0024] Experimental Example 1: Screening of the compound ratio of bistrifluron and pyrethrin to whitefly nymphs and determination of the co-toxicity coefficient

[0025] 1.1 Test pests and test methods

[0026] The whitefly adults reared on tomatoes in a greenhouse are inoculated on tomato seedlings grown without pests. After the adults lay eggs, the adults are removed in time, and the egg-laying seedlings are placed in a light incubator with an environmental temperature of 25°C. Wait until the eggs hatch to develop to the 2nd instar nymphs.

[0027] 1.2 Test agents

[0028] 5% bistrifluron dispersible concentrate (BASF Europe)

[0029] 1.5% pyrethroid emulsion (Yunnan Nanbao Biotechnology)

[0030] 2.5% Cyfluthrin EC (Shandong Kanghui Plant Protection)

[0031] 1.3 Experimental Methods

[0032] 1.3.1 Determination of the toxicity and relative toxicity index of pyrethroids, pyrethroids, and lambda-cyhalothrin against second-instar nymphs of whiteflies.

[0033] Bifenthrin was diluted with ultrapure water in a gradient to prepare concentrations of 1.25 mg / L, 2.5 mg / L, 5 mg / L, 10 mg / L, and 20 mg / L; pyrethroids were prepared to prepare concentrations of 12.5 mg / L, 25 mg / L, 50 mg / L, 100 mg / L, and 200 mg / L; and lambda-cyhalothrin was prepared to prepare concentrations of 12.5 mg / L, 25 mg / L, 50 mg / L, 100 mg / L, and 200 mg / L for later use.

[0034] Leaf immersion was used to treat infested leaves. Leaves with 30-50 whiteflies per leaf were immersed in the prepared pesticide solution for 5 seconds, then removed and air-dried in a cool place. The infested leaves were then placed in tissue culture bottles (9 cm in diameter) lined with moist filter paper. The bottles were then placed in a light incubator at 25°C, 70%-80% humidity, and a light intensity of 5000 LX:dark ratio of 14:10. Each treatment was repeated three times, with three leaves per replicate. The number of dead nymphs was checked at 24 h and 48 h. A blank control group was used. If the mortality rate in the control group was above 10%, the experiment was repeated. The criteria for confirming death were discoloration and shriveling of the insects. The corrected mortality rate was converted into a biostatistical probability value, and a linear regression analysis was performed between the probability value and the logarithmic values ​​of each pesticide concentration gradient to calculate the LC50 of each pesticide. 50 value.

[0035] LC in the test reagent 50 The reagent with the highest value, which is also the least toxic, is the standard reagent, and its relative toxicity is set to 1. The relative toxicity index of the test reagent is equal to the toxicity of the standard reagent and the toxicity of the test reagent.

[0036] 1.3.2 Determination of the co-toxicity coefficient of different ratios of pyrethroid and difenoconazole mixtures against whitefly nymphs

[0037] The different effective component proportion of the mixture of the dual propargite and pyrethrin was prepared, the preparation method was that the 20 mg / L dual propargite and 20 mg / L pyrethrin mother liquor was prepared first, and then the mixture of each proportion was prepared by mixing the mother liquor in the volume ratio of 1:1, 1:4, 1:10, 2:1 and 5:1. In the 1:1 proportion, the concentration of dual propargite and pyrethrin was 10 mg / L and 10 mg / L respectively; in the 1:4 proportion, the concentration of dual propargite and pyrethrin was 4 mg / L and 16 mg / L respectively; in the 1:10 proportion, the concentration of dual propargite and pyrethrin was 1.81 mg / L and 18.18 mg / L respectively; in the 2:1 proportion, the concentration of dual propargite and pyrethrin was 13.33 mg / L and 6.67 mg / L respectively; in the 5:1 proportion, the concentration of dual propargite and pyrethrin was 16.67 mg / L and 3.33 mg / L respectively; the total drug effective concentration of each proportion was 20 mg / L, and each proportion was diluted by high-purity water in the total drug effective concentration of 20 mg / L, 10 mg / L, 5 mg / L, 2.5 mg / L and 1.25 mg / L respectively. The toxicity of the mixture of different proportions of dual propargite and pyrethrin to the nymphs of Bemisia tabaci was determined by the method 1.3.1, and the co-toxicity coefficient was calculated. The toxicity of the mixture of different proportions of dual propargite and pyrethrin to the nymphs of Bemisia tabaci was determined by the method 1.3.1, and the co-toxicity coefficient was calculated.

[0038] 1.3.3 Determination of the co-toxicity coefficient of the mixture of different proportions of dual propargite and lambda-cyhalothrin to the nymphs of Bemisia tabaci

[0039] The mixture of different effective component proportion of dual propargite and lambda-cyhalothrin was prepared, the preparation method was that the 200 mg / L dual propargite and 200 mg / L lambda-cyhalothrin mother liquor was prepared first, and then the mixture of each proportion was prepared by mixing the mother liquor in the volume ratio of 1:1, 1:4, 1:10, 2:1 and 5:1 according to the method 1.3.2. The mixture of each proportion was diluted by high-purity water in the gradient of 200 mg / L, 100 mg / L, 50 mg / L, 25 mg / L and 12.5 mg / L, and the toxicity of the mixture of different proportions of dual propargite and lambda-cyhalothrin to the nymphs of Bemisia tabaci was determined by the method 1.3.1, and the co-toxicity coefficient was calculated.

[0040] The calculation method of the co-toxicity coefficient was as follows

[0041] According to the results of the bioassay, the toxicity regression equation, LC 50Values and relative toxicity indices. Finally, according to the method published by Sun Yunpei, the co-toxicity coefficient (Co-Toxicity Coefficient, abbreviated as C.T.C) of the mixture was calculated according to the following formula. A and B represent two single agents for mixing, and finally the co-toxicity coefficient of the mixture was obtained.

[0042]

[0043]

[0044] Theoretical toxicity index of (A + B) mixture = Toxicity index of agent A × Percentage of A in the mixture + Toxicity index of agent B × Percentage of B in the mixture.

[0045]

[0046] CTC ≤ 70 indicates antagonistic effect after mixing two single agents

[0047] 70 < CTC < 100 indicates additive effect after mixing two single agents

[0048] CTC ≥ 100 indicates synergistic effect after mixing two single agents

[0049] 1.4 Results and analysis

[0050] The toxicity and relative toxicity indices of bicyclopyrone, pyrethrin and lambda-cyhalothrin against the nymphs of Bemisia tabaci

[0051] The toxicity of bicyclopyrone, pyrethrin and lambda-cyhalothrin against the nymphs of Bemisia tabaci is shown in Table 1, and their LC 50 values are 1.638 mg / L, 25.17 mg / L and 136.14 mg / L respectively. Although both lambda-cyhalothrin and pyrethrin belong to pyrethroids, the toxicity of pyrethrin against the nymphs of Bemisia tabaci is 5.4 times that of lambda-cyhalothrin, and the control effect on the nymphs of Bemisia tabaci is significantly higher than that of lambda-cyhalothrin. The reason may be that pyrethroids are prone to drug resistance. After repeated use, the toxicity of pyrethroids to the nymphs of Bemisia tabaci in the field decreases, while pyrethrin belongs to natural pyrethroids, its structural components are more complex and it is not easy to produce drug resistance, and the activity of pyrethrin against the nymphs of Bemisia tabaci is higher than that of lambda-cyhalothrin. <00,00117>Table 1 Toxicity determination results of bicyclopyrone and pyrethrin against the nymphs of Bemisia tabaci

[0053]

[0054] 1.4.2 Co-toxicity coefficient of the mixture of bicyclopyrone and pyrethrin against the nymphs of Bemisia tabaci

[0055] The toxicity regression of the mixture of bistrifluron and pyrethrin to Bemisia tabaci was determined respectively, and the LC 50 The co-toxicity coefficients of the various complex insecticides were calculated according to Sun Yunpei's equation (1.4) with pyrethrin as the standard insecticide, and the joint action of the two single agents was divided into four categories according to the size of the measured co-toxicity coefficient. The co-toxicity coefficient between 70 and 100 indicates that the complex agent is additive; the co-toxicity coefficient greater than 100 indicates that the complex agent has a synergistic effect; if the co-toxicity coefficient is greater than 200, it indicates that the complex agent has a significant synergistic effect; and if the co-toxicity coefficient is less than 70, it indicates that there is obvious antagonism in the mixture.

[0056] From Table 2, the co-toxicity coefficients of bistrifluron and pyrethrin in the ratios of 1:1, 1:4, 1:10, 2:1, and 5:1 were 43.0, 126.9, 909.6, 20.2, and 129.4, respectively. The co-toxicity coefficients of the ratios of 1:4, 1:10, and 5:1 were greater than 100, indicating that they had a synergistic effect. The co-toxicity coefficient of the ratio of 1:10 was 909.6, which was the highest among the three ratios, followed by the ratio of 5:1. However, considering the economic and ecological benefits of the complex, the ratios of 1:4 and 1:10 of bistrifluron and pyrethrin were selected for this study.

[0057] Table 2 Comparison of the insecticidal toxicity of different ratios of bistrifluron:pyrethrin mixture to Bemisia tabaci nymphs

[0058]

[0059] Note: Pyrethrin, which has lower insecticidal activity, was used as the standard insecticide, and its toxicity index was set to 100.

[0060] 1.4.3 Co-toxicity coefficients of bistrifluron and lambda-cyhalothrin mixture to Bemisia tabaci nymphs

[0061] From Table 3, the co-toxicity coefficients of bistrifluron and lambda-cyhalothrin in the ratios of 1:1, 1:4, 1:10, 2:1, and 5:1 were 1.06, 5.59, 7.95, 2.63, and 6.11, respectively. The co-toxicity coefficients of the five ratios were all less than 100, indicating that the mixture of the two agents had an antagonistic effect on Bemisia tabaci nymphs. This suggests that although lambda-cyhalothrin and bistrifluron both belong to the pyrethrin class, the mixture of lambda-cyhalothrin and bistrifluron does not have significant synergistic activity against Bemisia tabaci nymphs. Pyrethroids typically have significant cross-resistance, indicating that pyrethroids are not suitable for complexing with bistrifluron to control Bemisia tabaci nymphs.

[0062] Table 3 Comparison of the insecticidal toxicity of different ratios of bistrifluron:lambda-cyhalothrin mixture to Bemisia tabaci nymphs

[0063]

[0064] Note: The lower insecticidal activity of the two single agents is bifenthrin, and the toxicity index is set to 100.

[0065] Example 2: Determination of the co-toxicity coefficient of bifenthrin and pyrethrin mixed preparation on adult whitefly

[0066] 2.1 Test pests

[0067] Adult whitefly: collected from the experimental field of the horticultural station of Jinling University of Science and Technology, and propagated in the laboratory.

[0068] 2.2 Test agents

[0069] Same as 1.2

[0070] 2.3 Experimental method

[0071] Bifenthrin was prepared into concentrations of 5 mg / L, 10 mg / L, 20 mg / L, 40 mg / L, 80 mg / L, and 100 mg / L by gradient with ultrapure water; pyrethrin was prepared into concentrations of 25 mg / L, 50 mg / L, 100 mg / L, 200 mg / L, and 400 mg / L. The 1:4 ratio of bifenthrin and pyrethrin mixed preparation was prepared by mixing 100 mL of 100 mg / L bifenthrin with 400 mL of 100 mg / L pyrethrin to form a mixed solution, which was then diluted by gradient to 5 concentrations. Leaf immersion method was used to determine the toxicity of adult whitefly. The 1:10 ratio of bifenthrin and pyrethrin mixed preparation was prepared by mixing 100 mL of 100 mg / L bifenthrin with 1000 mL of 100 mg / L pyrethrin to form a mixed solution, which was then diluted by gradient to 5 concentrations. Leaf immersion method was used to determine the toxicity of adult whitefly. Tomato leaves that had not been exposed to any agent were soaked in the prepared concentration of the agent for 10 seconds, and the leaves were naturally air-dried and placed in tissue culture bottles with moisturizing and defatted cotton. Adult whiteflies (male and female) were introduced, and the fresh-keeping film was sealed with a hole. The control group was treated with water.

[0072] There were 30-50 adult whiteflies in each bottle, and each treatment was repeated 3 times. After 48 hours, the mortality rate was corrected and converted into a biological probability value, and a linear regression analysis was established between the probability value and the logarithmic value of the concentration gradient of each agent. The LC 50 values of each agent were calculated. Finally, according to the data analysis, the relative mortality rate and the determination method of the co-toxicity coefficient were calculated.

[0073] 2.4 Results analysis

[0074] 2.4.1 Co-toxicity coefficient of the mixture of binpiperatri and pyrethrin to Bemisia tabaci adults

[0075] The toxicity regression of binpiperatri, pyrethrin and the mixtures of 1:4 and 1:10 to Bemisia tabaci adults was determined respectively, and the LC50 was calculated 50 Taking pyrethrin as the standard insecticide, the results showed that the co-toxicity coefficients of the two mixtures were 93.6 and 104.1 respectively, and the effects of the two mixtures to Bemisia tabaci adults were additive (1:4) and synergistic (1:10), which indicated that the mixture of the two single agents had synergistic activity to Bemisia tabaci nymphs, and the mixture of 1:10 had synergistic activity to Bemisia tabaci adults, so the mixture could be used for the prevention and control of Bemisia tabaci nymphs and adults.

[0076] Table 4 Co-toxicity coefficient of the mixture of binpiperatri and pyrethrin to Bemisia tabaci adults

[0077]

[0078] Note: Taking pyrethrin with lower insecticidal activity as the standard insecticide, the toxicity index was set to 100.

[0079] The above embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as a limitation to the scope of the patent of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A composition for controlling whitefly nymphs, characterized in that, It includes bispyribac-methyl and pyrethrin, wherein the mass ratio of bispyribac-methyl to pyrethrin is 1:4 or 1:

10.

2. The use of the composition of claim 1 in the preparation of an insecticide for controlling whitefly nymphs.

3. An insecticide for controlling whitefly nymphs, characterized in that, Includes the composition of claim 1.

Images