An insecticidal composition containing fluralaner and bacillus thuringiensis g033a and uses thereof

Abstract

The application provides a kind of insecticidal composition containing fluralaner and bacillus thuringiensis G033A and application thereof, and equivalent volume ratio of fluralaner and bacillus thuringiensis G033A strain is 9:1-1:9 (conversion effective ingredient weight ratio is 1:100-1:31638), preferably equivalent volume ratio is 5:5, 6:4, 7:3, 8:2 and 9:1.The composition of the application has obvious synergistic effect, can reduce the use amount of biological pesticide, reduce the prevention and treatment cost;At the same time, the use amount of chemical pesticide can also be reduced, and the harm to the environment is reduced.It is also beneficial to delay the generation of diamondback moth and rice leaf roller and other lepidoptera pests resistance.

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 folder is a significant migratory pest of rice, and chemical control has long been the primary control measure. However, prolonged selection pressure from pesticides has led to resistance in this insecticide. Since 2019, the National Agricultural Technology Extension Service Center has systematically conducted monitoring of pesticide resistance in the rice leaf folder. Currently, the rice leaf folder exhibits varying degrees of resistance to multiple pesticides, with moderate resistance to chlorantraniliprole and abamectin, and low-level resistance to agents such as flenazone, spinosad, and chlorpyrifos.

[0006] To overcome the drawbacks of single chemical insecticides, such as high resistance risks and severe environmental pollution, and single biological insecticides, such as high dosage and high control costs, this invention provides a highly efficient, safe, and economical insecticidal composition containing flurana and Bacillus thuringiensis G033A. At the optimal ratio, the composition exhibits a significant synergistic effect, reducing the amount of chemical and biological agents used while ensuring optimal control efficacy, lowering control costs, reducing environmental harm, and helping to delay the development of resistance.

[0007] There are no existing literature reports on the combined use of flurana and Bacillus thuringiensis G033A. Summary of the Invention

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

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

[0010] The insecticidal composition of the present invention is characterized in that the equivalent volume ratio of flurana and 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 of the present invention is characterized in that it further comprises an agriculturally acceptable adjuvant, and the active ingredient comprises 1-50% by weight.

[0012] The insecticidal composition of the present invention is characterized in that the adjuvants include dispersants, emulsifiers, disintegrants, stabilizers, antifreeze agents, wetting agents, synergists, penetrants, fillers, and solvents.

[0013] The insecticidal composition of the present invention is characterized in that the composition can be prepared into a suspension concentrate, a wettable powder, or a water-dispersible granule.

[0014] The insecticidal composition described in this invention is used for the control of crop pests. It is preferably used for the control of diamondback moth and rice leaf roller.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The insecticidal composition of the present invention consists of two active ingredients with different mechanisms of action. When mixed, they have a significant synergistic effect, which improves the control effect and also helps to overcome and delay the development of insecticide resistance in pests.

[0016] The composition of this invention reduces the amount of chemical and biological agents used, thereby lowering costs and mitigating environmental pollution. It also has good safety and meets the safety requirements for pesticide formulations.

[0017] The composition of the present invention has excellent insecticidal and control effects on diamondback moth and rice leaf roller, thereby improving their control efficacy. Detailed Implementation

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

[0019] Indoor Bioassay 1: Indoor Insecticidal Toxicity Determination and Combined Toxicity Determination of Flurana and Bacillus thuringiensis G033A against Diamondback Moth

[0020] Experimental subjects: Diamondback moth larvae collected from the field were raised and bred indoors using cabbage leaves. The 3rd instar larvae hatched from the F1 generation were used as the experimental insect source.

[0021] Single-agent toxicity assay method: Select healthy 3rd instar larvae with uniform growth as test insects.

[0022] 98% flurana technical grade was prepared into a stock solution with acetone, and then serially diluted with 0.1% Triton-100 water to obtain 5-7 working concentrations. 32000 IU / mg Bacillus thuringiensis G033A was directly prepared into a stock solution with 0.1% Triton-100 water, and then serially diluted with the same aqueous solution to obtain 5-7 working concentrations. Leaf discs with a diameter slightly smaller than 5 cm were punched into culture plates, immersed in the test solution for 10 s, removed, and allowed to air dry on absorbent paper before being transferred to a 5 cm diameter culture plate. Three leaf discs were placed in each well, and 12 test insects were inoculated. 12 test insects constituted one replicate, and each concentration was replicated three times. A control group was fed leaf discs containing the same volume of 0.1% Triton-100 aqueous solution. The treated test insects were reared at (26±1)℃, relative humidity of 40-70%, and photoperiod L / D = 16h / 8h. Three days later, the number of dead insects at different concentrations of the pesticide was checked and counted. The criterion for judging the death of the test insects was: if the insect could not crawl normally when touched with a brush, it was considered dead.

[0023] Combined toxicity assay method: Flureranil and Bacillus thuringiensis G033A were diluted to their respective LC50s with an aqueous solution containing 0.1% Triton-100. Nine ratios were set according to the ten division points of the additive effect line in the isoline method, and mixed at volume ratios of 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, and 9:1, respectively. Then, they were serially diluted to the working concentration. A blank control was set up, and the insecticidal activity was determined.

[0024] The corrected mortality rates for each treatment were converted into probability values, and the concentrations were converted into logarithmic values. The toxicity equation, LC50 (median lethal concentration), and 95% confidence limit were calculated using the least squares method. The toxicity index and co-toxicity coefficient (CTC) of the pesticides were calculated according to the methods specified in the agricultural industry standard "Guidelines for Indoor Bioassay Testing of Pesticides - Insecticides - Part 7: Determination of Combined Effects of Mixtures" (NY-T1154.7-2006).

[0025] When CTC ≤ 80, the composition exhibits an antagonistic effect; when 80 < CTC < 120, the composition exhibits an additive effect; and when CTC ≥ 120, the composition exhibits a synergistic effect.

[0026] Actual Toxicity Index (ATI) = (LC50 of Standard Reagent / LC50 of Test Reagent) × 100 Theoretical Toxicity Index (TTI) = Toxicity Index of Agent A × Percentage of A in the Mixture + Toxicity Index of Agent B × Percentage of B in the Mixture Co-toxicity coefficient (CTC) = [Actual toxicity index (ATI) of mixture / Theoretical toxicity index (TTI) of mixture] × 100.

[0027] The results of the toxicity test are shown in Table 1 below.

[0028] Table 1. Results of indoor toxicity tests of flurana and Bacillus thuringiensis G033A against diamondback moth larvae. ; As shown in Table 1, the equivalent volume ratio of flurana to Bacillus thuringiensis G033A in the insecticidal composition of the present invention is in the range of 1:9-9:1. The composition exhibits excellent insecticidal activity and significant synergistic effect, with CTC values ​​all greater than 120. Preferred equivalent volume ratios of flurana to Bacillus thuringiensis G033A are 6:4, 7:3, 8:2, and 9:1, with CTC values ​​all greater than 200.

[0029] Indoor Bioassay 2: Indoor Insecticidal Toxicity Determination and Combined Toxicity Determination of Flurana and Bacillus thuringiensis G033A against Rice Leaf Roller

[0030] Experimental subjects: Rice leaf roller larvae collected from paddy fields were raised and bred indoors in potted rice. The third instar larvae hatched from the F1 generation were used as the experimental insect source.

[0031] Single-agent toxicity assay method: Select healthy 3rd instar larvae with uniform growth as test insects.

[0032] The treatment method for rice leaves differs from that for cabbage leaves. The tips of the rice leaves are trimmed, leaving approximately 7-8 cm. The rice leaves are immersed in the test solution for 10 seconds, then removed and allowed to air dry on absorbent paper before being transferred to a 9 cm diameter culture plate. Twelve rice leaves are placed in each well, and twelve test insects are introduced. Twelve test insects constitute one replicate, and each concentration is repeated three times. The remaining treatments are the same as in the above-described indoor bioassay 1. Three days later, the number of dead insects at different concentrations is checked and counted. The criterion for insect death is: when the insect is gently touched with a brush, if it cannot crawl normally, it is considered dead.

[0033] Combined toxicity assay method: same as the above-mentioned indoor bioassay 1.

[0034] The results of the toxicity test are shown in Table 2 below.

[0035] Table 2. Results of indoor toxicity tests of fleroanalyte and Bacillus thuringiensis G033A against rice leaf folder larvae. ; As shown in Table 2, the equivalent volume ratio of flurana to Bacillus thuringiensis G033A in the insecticidal composition of the present invention is in the range of 1:9-9:1. The composition exhibits excellent insecticidal activity and significant synergistic effect against rice leaf folder, with CTC values ​​all greater than 120. Preferred equivalent volume ratios of flurana to Bacillus thuringiensis G033A are 5:5, 6:4, 7:3, 8:2, and 9:1, with CTC values ​​all greater than 200.

[0036] Field efficacy test 1: Field efficacy test of flenafil and Bacillus thuringiensis G033A against diamondback moth

[0037] Experimental subject: Diamondback moth Experimental Methods: The experimental plot was located in a cabbage planting base in Taihe County, Ma'anshan City, Anhui Province. The diamondback moth was predominantly in its 2nd-4th instar larvae, with an infestation rate of approximately 60% of the plants. The experiment consisted of 6 treatments: 5 pesticide treatments and 1 control. Each treatment was replicated in 3 plots, with each plot measuring 30 m². 2 (3 m × 10 m). Treatment groups were randomly arranged, with a 1 m protective row between adjacent treatments. Before application, a five-point sampling survey was conducted to investigate the baseline insect population in the field, with 20 cabbages sampled at each sampling point and clearly marked. After application, insect populations were surveyed at 1 day, 3 days, and 7 days to calculate the insect population reduction rate and corrected control efficacy. No abnormal weather occurred during this period.

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

[0039] Test reagents: Treatment A: 97% flurana technical grade diluted with acetone, recommended dosage (since flurana is not yet registered as a pesticide for controlling diamondback moth, the recommended dosage of the commonly used pesticide chlorantraniliprole for controlling diamondback moth is used): 2.5 g / acre; Treatment B: 32000 IU / mg Bacillus thuringiensis G033A wettable powder, recommended dosage: 100 g / acre; Treatment C: 32000 IU / mg Bacillus thuringiensis G033A wettable powder, recommended dose halved: 50 g / mu + 97% flurana technical grade, recommended dose reduced by 25%: 1.875 g / mu; Treatment D: 32000 IU / mg Bacillus thuringiensis G033A wettable powder, recommended dose halved: 50 g / mu + 97% flurana technical grade, recommended dose reduced by 50%: 1.25 g / mu; Treatment E: 32000 IU / mg Bacillus thuringiensis G033A wettable powder, recommended dose halved: 50 g / mu + 97% flurana technical grade, recommended dose reduced by 75%: 0.625 g / mu; Treatment F: Water control group.

[0040] Notes: 32000 IU / mg Bacillus thuringiensis G033A wettable powder (source: Wuhan Kenuo Biotechnology Co., Ltd.); 97% flurana technical grade (source: from our laboratory, obtained from veterinary drug Bevedere). ® (BRAVECTO) ® )purification).

[0041] Table 3. Field control efficacy of flurana and Bacillus thuringiensis G033A against diamondback moth. ; As shown in Table 3, the insecticidal composition of the present invention, containing flurana and Bacillus thuringiensis G033A, showed good control efficacy against diamondback moth at 1, 3, and 7 days after application, even when the recommended dosage of Bacillus thuringiensis G033A was halved and the dosage of the chemical pesticide flurana was reduced by 25% and 50%. The control efficacy was not significantly different from that of the recommended dosage of the chemical pesticide flurana, and the control efficacy exceeded 86% after 7 days. When the recommended dosage of Bacillus thuringiensis G033A was halved and the dosage of the chemical pesticide flurana was reduced by 75%, the control efficacy against diamondback moth at 1 and 3 days after application was higher than that of the recommended dosage of the biological pesticide Bacillus thuringiensis G033A. The control efficacy against diamondback moth at 7 days after application was slightly lower than that of the recommended dosage of the biological pesticide Bacillus thuringiensis G033A, but the difference was not significant. The results showed that the combination of flurana and Bacillus thuringiensis G033A can reduce the amount of chemical and biological pesticides used while ensuring high efficacy.

[0042] Field efficacy test 2: Field efficacy test of flenafil and Bacillus thuringiensis G033A against rice leaf roller

[0043] Test subject: Rice leaf roller Experimental Methods: The experimental plot was located in a rice field within the Anhui Agricultural University Central Anhui Comprehensive Experimental Station in Lujiang County, Hefei City, Anhui Province. The rice leaf roller mainly infested 1st-3rd instar larvae, with an infestation rate of approximately 10%. The experiment consisted of 6 treatments: 5 pesticide treatments and 1 control. Each treatment was replicated in 3 plots, with each plot measuring 30 m². 2 (3 m × 10 m). Treatment groups were randomly arranged, with a 1 m protective row between adjacent treatments. Before application, a five-point sampling survey was conducted to determine the baseline insect population in the field. Each sampling point surveyed approximately 200-250 rice plants within a 50 cm × 50 cm rectangular area. After application, insect populations were surveyed at 1 day, 3 days, and 7 days. The insect population reduction rate and corrected control efficacy were calculated in the same manner as in the field trial described above.

[0044] Treatment A: 97% flurana technical grade diluted with acetone, recommended dosage (since flurana is not yet registered as a pesticide for controlling rice leaf rollers, the recommended dosage of the commonly used pesticide chlorantraniliprole for controlling diamondback moth is used): 2.0 g / acre; Treatment B: 32000 IU / mg Bacillus thuringiensis G033A wettable powder, recommended dosage: 100 g / acre; Treatment C: 32000 IU / mg Bacillus thuringiensis G033A wettable powder, recommended dose halved: 50 g / acre + 97% flurana 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% flurana 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% flurana soluble granules, recommended dose reduced by 75%: 0.5 g / acre; Treatment F: Water control group.

[0045] Table 4. Field control efficacy of flurana and Bacillus thuringiensis G033A against rice leaf folder. ; As shown in Table 4, the insecticidal composition of the present invention, containing flurana and Bacillus thuringiensis G033A, showed good control effects against rice leaf folder 7 days after application when the recommended dosage of Bacillus thuringiensis G033A was halved and the dosage of flurana was reduced by 25% and 50%. The control efficacy was not significantly different from that of the recommended dosage of flurana, but significantly higher than that of Bacillus thuringiensis G033A alone at the recommended dosage. Even when the recommended dosage of Bacillus thuringiensis G033A was halved and the dosage of flurana was reduced by 75%, the control effect against rice leaf folder remained good, with a control efficacy of 55.28 ± 5.61% after 7 days, which was higher than that of Bacillus thuringiensis G033A alone at the recommended dosage. The results showed that the combination of freranil and Bacillus thuringiensis G033A not only had a reduced-feed and enhanced-efficiency control effect on diamondback moth on cabbage, but also had a reduced-feed and enhanced-efficiency control effect on rice leaf roller in paddy fields.

[0046] Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention shall be included within the scope of protection of this invention. All percentages in the formulations are by weight. The processing techniques for each formulation of the compositions of this invention are existing technologies and may vary depending on different circumstances.

Claims

1. An insecticidal composition containing flenafil and Bacillus thuringiensis G033A, characterized in that, The active ingredients include flurana and Bacillus thuringiensis G033A, wherein the weight ratio of flurana and Bacillus thuringiensis G033A is 1:100-1:31638; and the concentration of Bacillus thuringiensis G033A is 32000 IU / mg.

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

3. The insecticidal composition according to claim 2, characterized in that, The additives include dispersants, emulsifiers, disintegrants, stabilizers, antifreeze agents, wetting agents, synergists, penetrants, fillers, and solvents.

4. The insecticidal composition according to claim 3, characterized in that: The composition can be prepared into dosage forms such as suspensions, wettable powders, and water-dispersible granules.

5. Use of the insecticidal composition according to any one of claims 1-4 for the control of crop pests.

6. The use according to claim 5, characterized in that, Used for the control of diamondback moth and rice leaf roller.