Insecticidal composition containing fluralan and bacillus thuringiensis G033A and application thereof

Abstract

The invention provides an insecticidal composition containing flurala and bacillus thuringiensis G033A and application of the insecticidal composition. The equivalent volume ratio of flurala to bacillus thuringiensis G033A is 9: 1-1: 9 (converted into that the weight ratio of effective components is 1: 100-1: 31638), and preferably, the equivalent volume ratio is 5: 5, 6: 4, 7: 3, 8: 2 and 9: 1. The composition disclosed by the invention has an obvious synergistic effect, the use amount of a biological agent can be reduced, and the prevention and treatment cost is reduced; meanwhile, the use amount of chemical pesticides can be reduced, and the harm to the environment is reduced. The generation of drug resistance of lepidoptera pests such as plutella xylostella and cnaphalocrocis medinalis can be delayed.

Description

Technical Field

[0001] This invention belongs to the field of agricultural chemistry, specifically relating to an insecticidal composition containing fluorellana and Bacillus thuringiensis strain G033A. Background Technology

[0002] Fluralaner is a broad-spectrum insecticidal compound accidentally discovered during research on o-formamide and formamide phthalates. It exhibits good insecticidal activity against pests in the orders Acari, mites, fleas, Diptera, Hemiptera, and Lepidoptera, with toxicity higher than or comparable to the commonly used insecticide fipronil. More importantly, fluralaner shows no cross-resistance with existing insecticides and retains good insecticidal activity against some resistant pests, such as houseflies resistant to dieldrin, planthoppers resistant to fipronil, and fruit flies resistant to cyclopentadiene insecticides; its insecticidal activity is not significantly different from that of the corresponding susceptible strains. Furthermore, fluralaner is safe for non-target organisms such as mammals, zebrafish, and birds, demonstrating broad application prospects.

[0003] Bacillus thuringiensis (Bt) Bacillus thuringiensis Bacillus thuringiensis (Bt) is currently the most widely used and earliest applied bacterial pathogenic microorganism for pests. my country introduced Bt powder in the mid-1950s, subsequently isolated strains, propagated them, and conducted biocontrol experiments on corn borers. Later, its application was expanded to control over more than 100 lepidopteran pests, including pine caterpillars, rice leaf rollers, cutworms, and cotton bollworms. Currently, the utilization of Bt strains includes directly producing microbial agents and extracting insecticidal proteins for transgenic application. Producing microbial agents is the most direct and simplest method, but it also suffers from unstable efficacy and low insecticidal efficiency. Bacillus thuringiensis strain G033A is my country's first genetically engineered microbial pesticide, jointly developed by the Institute of Plant Protection of the Chinese Academy of Agricultural Sciences and Wuhan Kenuo Biotechnology Co., Ltd. It is a bivalent genetically engineered bacterium with high toxicity against important agricultural pests such as Coleoptera and Lepidoptera.

[0004] The diamondback moth, a major global agricultural pest, faces a severe problem with pesticide resistance. It causes $4-5 billion in global economic losses annually and has developed resistance to almost all pesticides. Currently, the diamondback moth is the first insect reported in the world to have developed high resistance to Bt biological pesticides in the field. Normally, pests that evolve resistance pay a price for survival, such as increased mortality, stunted growth, and reduced offspring numbers. However, the diamondback moth, after evolving high resistance to Bt biological pesticides, has not exhibited these significant survival costs.

[0005] The rice leaf roller is an important migratory pest on rice. Chemical control has been the main prevention and control measure for a long time. However, long-term pesticide selection pressure has led to resistance of the pest to some insecticides. Since 2019, the National Agricultural Technology Extension Service Center has systematically carried out resistance monitoring of the rice leaf roller. At present, the rice leaf roller has developed resistance to various insecticides to varying degrees, and has developed moderate resistance to chlorantraniliprole and abamectin, and low resistance to flupyradifurone, spinetoram and chlorpyrifos.

[0006] In order to overcome the disadvantages of single chemical insecticide, such as high resistance risk, serious environmental pollution, and high use amount and prevention and control cost of single biological insecticide, the present application provides an efficient, safe and economical insecticidal composition containing flupyradifurone and Bacillus thuringiensis G033A. In the optimal proportion, the composition has obvious synergistic effect, reduces the use amount of chemical and biological pesticides to ensure the optimal control effect, reduces the prevention and control cost, reduces the harm to the environment, and delays the generation of resistance.

[0007] There is no literature report on the combination of flupyradifurone and Bacillus thuringiensis G033A in the prior art. SUMMARY

[0008] To solve the problems in the prior art, the present application provides the following technical scheme: An insecticidal composition containing flupyradifurone and Bacillus thuringiensis G033A, characterized in that the active ingredients comprise flupyradifurone and Bacillus thuringiensis G033A, and the equivalent volume ratio of flupyradifurone to Bacillus thuringiensis G033A is 9:1-1:9 (converted to the effective ingredient weight ratio of 1:100-1:31638).

[0009] The equivalent volume ratio refers to that flupyradifurone and Bacillus thuringiensis G033A are diluted to LC50 respectively with 0.1% Triton-100 aqueous solution, and then mixed in the volume ratio of 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2 or 9:1.

[0010] The insecticidal composition, characterized in that the equivalent volume ratio of flupyradifurone to Bacillus thuringiensis G033A is 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2 or 9:1.

[0011] The insecticidal composition, characterized in that it further comprises an agriculturally acceptable adjuvant, and the weight percentage content of the active ingredient is 1-50%.

[0012] The insecticidal composition of the present application is characterized in that the adjuvant comprises dispersing agent, emulsifying agent, disintegrating agent, stabilizing agent, anti-freezing agent, wetting agent, synergist, penetrating agent, filler, solvent.

[0013] The insecticidal composition of the present application is characterized in that the composition can be prepared into the dosage forms of suspension, wettable powder, water dispersible granule.

[0014] The insecticidal composition of the present application is used for controlling crop pests.

[0015] Compared with the prior art, the present application has the following beneficial effects: The insecticidal composition of the present application is composed of two effective components with different action mechanisms, and has obvious synergistic effect after mixing, thereby improving the control effect and being beneficial to overcoming and delaying the generation of pest resistance.

[0016] The mixing of the composition of the present application reduces the use amount of chemical and biological pesticides, thereby reducing the cost and the pollution to the environment, and being safe and meeting the safety requirements of pesticide preparation.

[0017] The composition of the present application has excellent insecticidal and control effects on Plutella xylostella and Cnaphalocrocis medinalis, and improves the control effect. DETAILED DESCRIPTION

[0018] The specific embodiments of the present application will be described in detail below in combination with the implementation examples, but it should be understood that the protection scope of the present application is not limited by the specific embodiments.

[0019] Indoor biological test 1: indoor insecticidal toxicity test and joint toxicity test of fluralaner and Bacillus thuringiensis G033A on Plutella xylostella

[0020] Test object: the Plutella xylostella larvae collected in the field are bred in the room with cabbage leaves, and the 3rd instar larvae bred after the F1 generation is hatched are used as the test insect source.

[0021] Single-agent toxicity test method: select the 3rd instar initial larvae with consistent growth and good health as the test insects.

[0022] 98% fluacrypyrim original drug with acetone to prepare mother liquor, and then 0.1% Triton-100 water gradient dilution 5~7 working concentration. 32000 IU / mg Bacillus thuringiensis G033A directly with 0.1% Triton-100 water to prepare mother liquor, and then with the same aqueous solution gradient dilution 5~7 working concentration in turn. With puncher to make the diameter slightly smaller than 5 cm culture plate hole diameter of leaf disc, immerse in the test solution for 10 s, take out and placed on the water absorption paper natural drying, then to the diameter of 5 cm culture plate, put 3 leaf discs in each hole, and access to 12 test insects. 12 test insects for a repeat, each concentration is repeated three times. With 0.1% Triton-100 aqueous solution containing the same volume of solvent treated leaf disc feeding group as control. The treated test insects are reared at (26±1)℃, relative humidity of 40-70%, photoperiod L / D= 16h / 8h. After 3 days, check and count the number of dead insects at different concentrations, and the death of test insects is judged by the following criteria: using a brush to touch the insect body, and it cannot crawl normally is considered dead.

[0023] Joint toxicity determination method: fluacrypyrim and Bacillus thuringiensis G033A are diluted to LC50 respectively with 0.1% Triton-100 aqueous solution, 9 ratios are set according to the ten equal points of the additive effect line in the isobologram method, mixed in the volume ratio of 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, 9:1, and then gradient dilution to working concentration in turn, set blank control, and carry out insecticidal activity determination.

[0024] Convert the corrected mortality of each treatment into probability value, and convert the concentration into logarithmic value. The toxicity equation, median lethal concentration LC50 and 95% confidence limit are calculated by least square method. The toxicity index and co-toxicity coefficient (CTC) of the pesticide are calculated according to the method specified in the agricultural industry standard "Pesticide indoor biological determination test guidelines insecticides part 7: determination of combined action of mixtures" (NY-T1154.7-2006).

[0025] When CTC≤80, the composition shows antagonism, when 80<CTC<120, the composition shows additive effect, and when CTC≥120, the composition shows synergistic effect.

[0026] Actual toxicity index (ATI)= (standard pesticide LC50 / test pesticide LC50) x 100 Theoretical toxicity index (TTI)= A pesticide toxicity index x percentage content of A in the mixture + B pesticide toxicity index x percentage content of B in the mixture Co-toxicity coefficient (CTC)= [mixture actual toxicity index (ATI) / mixture theoretical toxicity index (TTI)] x 100.

[0027] The results of the virulence determination are shown in Table 1 below.

[0028] Table 1 Results of indoor virulence determination of fluralaner and Bacillus thuringiensis G033A on Plutella xylostella larvae ; As shown in Table 1, the equivalent volume ratio of fluralaner and Bacillus thuringiensis G033A in the insecticidal composition of the present application is in the range of 1:9-9:1, and the composition has excellent insecticidal activity and significant synergistic effect, with CTC all greater than 120. Preferably, the equivalent volume ratio of fluralaner and Bacillus thuringiensis G033A is 6:4, 7:3, 8:2 and 9:1, and the CTC is all greater than 200.

[0029] Indoor bioassay 2: indoor insecticidal virulence determination and joint virulence determination of fluralaner and Bacillus thuringiensis G033A on Cnaphalocrocis medinalis

[0030] Test object: Cnaphalocrocis medinalis larvae collected from rice fields were bred in the laboratory using potted rice, and 3rd instar larvae bred after F1 hatching were used as test insect sources.

[0031] Single-dose virulence determination method: select healthy 3rd instar larvae as test insects.

[0032] The treatment method of rice leaves is different from that of cabbage leaves. The rice leaves are cut to leave about 7-8 cm, immersed in the test liquid for 10 s, taken out and naturally dried on the water absorption paper, then transferred to a 9 cm diameter culture plate, 12 rice leaves are placed in each hole, and 12 test insects are introduced. 12 test insects are a repeat, and each concentration is repeated three times. The rest of the treatment is the same as the above indoor bioassay 1. Check and count the number of dead insects at different concentrations after 3 days, and the death judgment standard of test insects: use a brush to touch the insect body, and it cannot move normally, which is considered dead.

[0033] Joint virulence determination method: the same as the above indoor bioassay 1.

[0034] The results of the virulence determination are shown in Table 2 below.

[0035] Table 2 Results of indoor virulence determination of fluralaner and Bacillus thuringiensis G033A on Cnaphalocrocis medinalis larvae ; As shown in Table 2, the equivalent volume ratio of fluralaner and Bacillus thuringiensis G033A in the insecticidal composition of the present application is in the range of 1:9-9:1, and the composition has excellent insecticidal activity and significant synergistic effect, with CTC all greater than 120. Preferably, the equivalent volume ratio of fluralaner and Bacillus thuringiensis G033A is 5:5, 6:4, 7:3, 8:2 and 9:1, and the CTC is all greater than 200.

[0036] Field efficacy test 1: field efficacy test of fluralaner and bacillus thuringiensis G033A against plutella xylostella

[0037] Test object: plutella xylostella Test method: the test plot was located in the cabbage planting base in taixing county, ma'anshan city, anhui province, and the plutella xylostella was mostly 2-4 instar larvae, with a damaged plant rate of about 60%. The test was designed with 6 treatments, including 5 pesticide treatments and 1 blank control, each treatment was repeated 3 times, each plot was 30 m 2 (3 m x 10 m). The treatment groups were randomly arranged, and 1 m protection row was set between adjacent treatments. Five-point sampling was used to investigate the insect population base before spraying, 20 cabbages were investigated at each sampling point, and the marks were made. The insect population was investigated at 1d, 3d, 7d after spraying, the insect population reduction rate and the corrected control effect were calculated, and there was no abnormal weather during the period.

[0038] Insect population reduction rate=(treatment before insect population-treatment after insect population) / treatment before insect population x 100%; Control effect=(treatment area insect population reduction rate-control area insect population reduction rate) / (1-control area insect population reduction rate) x 100%.

[0039] Test pesticides: Treatment A: acetone diluted 97% fluralaner technical material, recommended dose (since fluralaner has not been registered as a pesticide for controlling plutella xylostella, the recommended dose of commonly used pesticide chlorantraniliprole for controlling plutella xylostella is used): 2.5 g / m Treatment B: 32000iu / mg bacillus thuringiensis G033A wettable powder, recommended dose: 100 g / m Treatment C: 32000iu / mg bacillus thuringiensis G033A wettable powder, recommended dose halved: 50 g / m + 97% fluralaner technical material, recommended dose reduced by 25%: 1.875 g / m Treatment D: 32000iu / mg bacillus thuringiensis G033A wettable powder, recommended dose halved: 50 g / m + 97% fluralaner technical material, recommended dose reduced by 50%: 1.25 g / m Treatment E: 32000iu / mg bacillus thuringiensis G033A wettable powder, recommended dose halved: 50 g / m + 97% fluralaner technical material, recommended dose reduced by 75%: 0.625 g / m Treatment F: water control treatment group.

[0040] Note: 32000 IU / mg Bacillus thuringiensis G033A wettable powder (from Wuhan Konno Biological Technology Co., Ltd.); 97% fluralaner technical material (from the laboratory from the veterinary drug Bayvelduo ® (BRAVECTO ® ) purified).

[0041] Table 3 Field control effect of fluralaner and Bacillus thuringiensis G033A on Plutella xylostella ; As shown in Table 3, the insecticidal composition of the present application, fluralaner and Bacillus thuringiensis G033A, when the recommended dosage of Bacillus thuringiensis G033A is halved, the dosage of chemical pesticide fluralaner is reduced by 25% and 50%, still has good control effect on Plutella xylostella at 1 day, 3 days and 7 days after treatment, and there is no significant difference in control effect with the recommended dosage of chemical pesticide fluralaner, and the control effect after 7 days is more than 86%; when the recommended dosage of Bacillus thuringiensis G033A is halved, the dosage of chemical pesticide fluralaner is reduced by 75%, the control effect on Plutella xylostella at 1 day and 3 days after treatment is higher than that of the recommended dosage of biological pesticide Bacillus thuringiensis G033A, and the control effect on Plutella xylostella at 7 days after treatment is slightly lower than that of the recommended dosage of biological pesticide Bacillus thuringiensis G033A, but the difference is not significant. The results show that the combination of fluralaner and Bacillus thuringiensis G033A can reduce the use amount of chemical pesticides and biological pesticides while ensuring high control effect.

[0042] Field control effect determination 2: Field control effect of fluralaner and Bacillus thuringiensis G033A on Cnaphalocrocis medinalis

[0043] Test object: Cnaphalocrocis medinalis Test method: The test plot is located in the rice planting field of Anhui Agricultural University Wanzhong Comprehensive Test Station in Lujiang County, Hefei City, Anhui Province, and the occurrence of Cnaphalocrocis medinalis is mainly 1-3 instar larvae, and the damaged plant rate is about 10%. The test is designed for 6 treatments, including 5 pesticide treatments and 1 blank control, each treatment is repeated 3 times, each plot is 30 m 2 (3 m x 10 m). The treatment groups are randomly arranged, and 1 m protection row is set between adjacent treatments. Before spraying, five-point sampling is used to investigate the insect population base, and each sampling point investigates the rice (about 200-250 plants) in a 50 cm x 50 cm rectangular circle. Investigate the insect population at 1 d, 3 d and 7 d after spraying, calculate the insect population reduction rate and the corrected control effect, which is the same as the above field test.

[0044] Treatment A: 97% fluralaner technical diluted with acetone, recommended dose (since fluralaner is not registered as a pesticide for controlling C. oryzae, the recommended dose of chlorantraniliprole for controlling P. xylostella was used): 2.0 g / acre; Treatment B: 32000 IU / mg Bacillus thuringiensis G033A wettable powder, recommended dose: 100 g / acre; Treatment C: 32000 IU / mg Bacillus thuringiensis G033A wettable powder, recommended dose halved: 50 g / acre + 97% fluralaner soluble granules, recommended dose reduced by 25%: 1.5 g / acre; Treatment D: 32000 IU / mg Bacillus thuringiensis G033A wettable powder, recommended dose halved: 50 g / acre + 977% fluralaner soluble granules, recommended dose reduced by 50%: 1.0 g / acre; Treatment E: 32000 IU / mg Bacillus thuringiensis G033A wettable powder, recommended dose halved: 50 g / acre + 5.7% fluralaner soluble granules, recommended dose reduced by 75%: 0.5 g / acre; Treatment F: water control group.

[0045] Table 4 Field control effect of fluralaner and Bacillus thuringiensis G033A on C. oryzae ; As shown in Table 4, the insecticidal composition of the present application, fluralaner and Bacillus thuringiensis G033A, when the recommended dose of Bacillus thuringiensis G033A is halved, the chemical pesticide fluralaner is reduced by 25% and 50%, has good control effect on C. oryzae 7 days after treatment, and there is no significant difference in control effect with the recommended dose of chemical pesticide fluralaner, and is significantly higher than the recommended dose of Bacillus thuringiensis G033A alone; when the recommended dose of Bacillus thuringiensis G033A is halved, the chemical pesticide fluralaner is reduced by 75%, it still has good control effect on C. oryzae, and the control effect is 55.28±5.61% 7 days after treatment, which is higher than the recommended dose of Bacillus thuringiensis G033A alone. The results show that the combination of fluralaner and Bacillus thuringiensis G033A not only has the effect of reducing the amount of P. xylostella on cabbage, but also has the effect of reducing the amount of C. oryzae in rice field.

[0046] Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application. All percentages in the formula are weight percentages. The processing technology of each preparation of the composition of the present application is prior art, and can be changed according to different situations.

Claims

1. An insecticidal composition containing flenafil and Bacillus thuringiensis G033A, characterized in that, The active ingredients include flurana and Bacillus thuringiensis G033A, with an equivalent volume ratio of flurana to Bacillus thuringiensis G033A of 9:1 to 1:9 (equivalent to an effective ingredient weight ratio of 1:100 to 1:31638); the concentration of Bacillus thuringiensis G033A is 32000 IU / mg.

2. The insecticidal composition according to claim 1, characterized in that, The equivalent volume ratios of flurana and Bacillus thuringiensis G033A are 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, and 9:

1.

3. The insecticidal composition according to any one of claims 1-2, characterized in that, It also contains agriculturally acceptable adjuvants, with the active ingredient comprising 1-50% by weight.

4. The insecticidal composition according to claim 3, characterized in that, The additives include dispersants, emulsifiers, disintegrants, stabilizers, antifreeze agents, wetting agents, synergists, penetrants, fillers, and solvents.

5. The insecticidal composition according to claim 4, characterized in that: The composition can be prepared into dosage forms such as suspensions, wettable powders, and water-dispersible granules.

6. Use of the insecticidal composition according to any one of claims 1-5 for the control of crop pests.

7. The use according to claim 6, characterized in that... Used for the control of diamondback moth and rice leaf roller.