A biological pesticide for controlling Phyllotreta striolata (Fabricius)

Abstract

The present invention belongs to the technical field of pesticides, and particularly relates to a biological pesticide for controlling Phyllotreta striolata. A biological pesticide for controlling Phyllotreta striolata, wherein the active ingredient of the biological pesticide is composed of a polyhedrosis virus compounded with emodin, milbemycin or dihydrosanguinarine, and the mass ratio of the polyhedrosis virus to emodin, milbemycin or dihydrosanguinarine is 1-100:100-1. When the polyhedrosis virus in the biological pesticide of the present invention is compounded with emodin, milbemycin or dihydrosanguinarine, it shows a synergistic effect within a certain mass ratio range, can improve the control effect on Phyllotreta striolata, reduce the dosage of the active ingredient, and reduce pesticide residues and control costs.

Description

Technical Field

[0001] The invention belongs to the technical field of pesticides, and particularly relates to a biological pesticide for preventing and controlling radish yellow striped flea beetles. Background Art

[0002] The striped yellow flea beetle (Phyllotreta strilata) belongs to the family Chrysomelidae in the order Coleoptera. It mainly harms cruciferous vegetables including Chinese cabbage, Chinese cabbage, radish and rapeseed. It is an economically important pest of cruciferous vegetables worldwide. Both adults and larvae of the striped yellow flea beetle can harm crops. Adults mainly feed on the aboveground mesophyll, causing a large number of holes. The holes will become larger as the leaves grow. In severe cases, the entire plant will be eaten away. The most serious damage is to seedlings. The larvae bite the host root bark, peel the root bark or bore into the root, forming irregular stripes. They can also bite off the fibrous roots, causing the aboveground leaves of the seedlings to turn yellow, wilt and die. They can also spread root soft rot.

[0003] For a long time, chemical control has been the fastest and most efficient way to control agricultural pests. For example, cypermethrin, deltamethrin, spinosad, avermectin, thiamethoxam, clothianidin and pyridamole can control the yellow striped flea beetle, but chemical control has also caused the "3R" problem of pesticides. The yellow striped flea beetle has developed varying degrees of resistance to a variety of existing pesticides, reducing the control effect. Therefore, research and screening of effective control agents has urgent practical significance.

[0004] The synergistic effect of pesticides refers to the mutual promotion of the active ingredients of various compound pesticides, making the actual effect after compounding greater than the theoretical effect. The rational compound use of pesticides can improve the control effect of pesticides, delay the development of pesticide resistance, reduce the amount of each ingredient, and help reduce pesticide residues and control costs.

[0005] At present, relevant research reports have been published. In the study of insecticidal and enzyme inhibition activity, it was found that the insecticidal activity of quinone compounds against brown planthoppers is better than that of oriental armyworms. The preliminary study of its insecticidal mechanism through enzyme activity inhibition test found that rhamnol significantly inhibited the activity of acetylcholinesterase and glutathione-S-transferase, and activated the activity of cytochrome P450s. The insecticidal mechanism may be related to increasing the sensitivity of insects to drugs by inducing activation of P450s and blocking the phase II metabolic system by inhibiting glutathione-S-transferase activity. Nervous system and motor dysfunction are also important causes of insect death. The insecticidal activity of rhamnol against brown planthoppers and oriental armyworms was also disclosed in the research report, with LC50 of 84.30μg / mL and 548.74μg / mL, respectively.

[0006] Milbemectin is an antibiotic insecticide developed by Japan Sanko Chemical Co., Ltd. 3and milbemectin A 4 It is composed of 3:7 mass ratio. Mibemycin is a γ-aminobutyric acid inhibitor that acts on the peripheral nervous system. By increasing the binding force of mibemycin and γ-aminobutyric acid, the chloride ion flow is increased, thereby exerting insecticidal and acaricidal activity. It is effective against pests at all growth stages, and the mode of action is contact killing and stomach poisoning.

[0007] Dihydrosanguinarine is an alkaloid compound isolated and purified from the leaves of Macrocarpon microcarpa. Compared with other isolated alkaloid compounds such as demethylsanguinarine, dihydrochelerythrine, 6-acetonyldihydrosanguinarine, berberine, 6-methoxydihydrosanguinarine, β-allocryptine and protoopine, dihydrosanguinarine has better biological activity against armyworm, diamondback moth, cabbage looper and cotton bollworm, which can provide support for the development of biological insecticides.

[0008] At present, there is no report on the compounding of polyhedrosis virus with rhamnine, malbectin or dihydrosanguinarine.

[0009] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0010] The object of the present invention is to provide a biological pesticide for controlling radish yellow striped flea beetle, which can improve the control effect on the yellow striped flea beetle, reduce the dosage of active ingredients, and reduce pesticide residues and control costs.

[0011] To achieve the above object, the present invention provides the following technical solutions:

[0012] A biological pesticide for preventing and controlling yellow striped flea beetles of radish, wherein the active ingredient of the biological pesticide is compounded with polyhedrosis virus and rhamnosine, malbenomycin or dihydrosanguinarine, and the mass ratio of the polyhedrosis virus to rhamnosine, malbenomycin or dihydrosanguinarine is 1-100:100-1.

[0013] Preferably, the polyhedrosis virus is Spodoptera exigua nuclear polyhedrosis virus, Spodoptera litura nuclear polyhedrosis virus, Autographa californica nuclear polyhedrosis virus, Helicoverpa armigera nuclear polyhedrosis virus, Tea geometrid nuclear polyhedrosis virus or Pine caterpillar cytoplasmic polyhedrosis virus.

[0014] Preferably, the polyhedrosis virus is 200 billion PIB / g of Spodoptera exigua nuclear polyhedrosis virus.

[0015] Preferably, the mass ratio of the polyhedrosis virus to rheumatoid arthritis is 1-19:39-1.

[0016] Preferably, the mass ratio of the polyhedrosis virus to mycobactin is 1-25:40-1.

[0017] Preferably, the mass ratio of the polyhedrosis virus to sanguinarine is 1-18:1-6.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) When the polyhedrosis virus in the biological pesticide of the present invention is compounded with rhamnosine, mitoflavin or dihydrosanguinarine, a synergistic effect is exhibited within a certain mass ratio range, which can improve the control effect of yellow striped flea beetles, reduce the amount of active ingredients used, and reduce pesticide residues and control costs.

[0020] (2) The biological pesticide of the present invention can delay the development of resistance of the yellow flea beetle, thus overcoming the defects of using a single active ingredient.

[0021] (3) The effective ingredients in the biopesticide of the present invention are biologically active ingredients, which are green and safe. DETAILED DESCRIPTION

[0022] The following is a clear and complete description of the technical solution of the patent of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Example :Indoor biological activity test

[0024] 1. Experimental subjects: The yellow striped flea beetles were collected from the cruciferous vegetable field and raised for multiple generations on fresh and clean radish leaves in an artificial climate incubator with a temperature of (25±1)℃, a humidity of 75%, and a photoperiod of 14L:10D. The adults of the yellow striped flea beetles with similar body size were selected as experimental subjects.

[0025] 2. Test reagents

[0026] 200 billion PIB / g of beet armyworm nuclear polyhedrosis virus (Jinan Baiyun Industrial Co., Ltd., Henan Province), 95% rhubarb technical (Shanghai Aladdin Biochemical Technology Co., Ltd.), 95% mibamectin technical (Nanjing Ibega Technology Co., Ltd.), 98% dihydrosanguinarine technical (Shanghai Yuanye Biotechnology Co., Ltd.).

[0027] After the test drugs are prepared into single-dose stock solutions, multiple groups of ratios are set up. Each single-dose stock solution and each group of mixed ratios are set up with 5 mass concentration gradients according to the equal proportion method. The volume of each mass concentration solution is 50mL. All drugs are prepared and used immediately.

[0028] 3. Test methods

[0029] The leaf dipping method was used (refer to "NY / T 1154.14-2008 Pesticide Indoor Bioassay Test Guidelines Insecticide Part 14: Leaf Dipping Method"). Cut fresh and clean radish leaves into leaf segments, pick up the cut leaf segments with tweezers and dip them into the test agent solution. After 10 seconds, take them out and dry them in a culture dish (9 cm in diameter) containing soaked filter paper. In each culture dish, 20 test subjects were placed, and the gauze was fixed on the mouth of the dish with a rubber band to prevent escape. The culture dish was placed in an artificial climate incubator with a temperature of (25±1)℃, a humidity of 75%, and a photoperiod of 14L:10D for feeding and observation. Each treatment was repeated 4 times, and the treatment of distilled water was set as a blank control. The death of the test insects was observed 72 hours after the treatment, and the total number of insects and the number of dead insects in each treatment were recorded respectively, and the corrected mortality rate of each treatment was calculated based on this.

[0030]

[0031] In the above formula: P--mortality rate, unit is %; K--number of dead insects; N--total number of insects treated.

[0032]

[0033] In the above formula: P 1 --Adjusted mortality rate, in %; P t --Treatment mortality rate, in %; P 0 --Blank control mortality rate, in %.

[0034] 4. Data analysis: DPS software was used to perform regression analysis on the logarithmic values ​​of the concentration of each treatment agent and the corrected mortality probability value of each treatment, and the LC of each treatment agent was calculated. 50 , and the co-toxicity coefficient (CTC value) of the mixture was calculated according to Sun Yunpei's method.

[0035] 5. Efficacy evaluation

[0036] The synergistic effect of the drug was evaluated based on the calculated co-toxicity coefficient (CTC). CTC≤80 was antagonistic, 80<CTC<120 was additive, and CTC≥120 was synergistic. The results are shown in Table 1-2.

[0037] Table 1 The results of the toxicity test of Spodoptera exigua nuclear polyhedrosis virus and rhamnolide against yellow flea beetle

[0038]

[0039] As shown in Table 1, within the mass ratio of 1-19:39-1, the co-toxicity coefficient of Spodoptera exigua nuclear polyhedrosis virus and rhamnosus to the yellow flea beetle was greater than 120, showing a synergistic effect.

[0040] Table 2 Results of toxicity test of Spodoptera exigua nuclear polyhedrosis virus and mycomycin complex against yellow flea beetle

[0041]

[0042]

[0043] As shown in Table 2, within the mass ratio of 1-25:40-1, only at 20:1, the co-toxicity coefficient of Spodoptera exigua nuclear polyhedrosis virus and mycomycin against yellow flea beetle was between 80-120, showing an additive effect, while the rest of the co-toxicity coefficients were greater than 120, showing a synergistic effect.

[0044] Table 3 Results of toxicity test of Spodoptera exigua nuclear polyhedrosis virus and dihydrosanguinarine against yellow flea beetle

[0045]

[0046] As shown in Table 3, within the mass ratio of 1-18:6-1, the co-toxicity coefficient of Spodoptera exigua nuclear polyhedrosis virus and dihydrosanguinarine against the yellow striped flea beetle was greater than 120, showing a synergistic effect.

[0047] In summary, when the beet armyworm nuclear polyhedrosis virus in the biological pesticide of the present invention is compounded with rhamnosine, mitramectin or dihydrosanguinarine, it exhibits a synergistic effect within a certain mass ratio range, can improve the control effect on the yellow striped flea beetle, reduce the dosage of the active ingredient, and reduce pesticide residues and control costs.

[0048] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. Application of a biological pesticide in controlling radish yellow striped flea beetle, It is characterized in that The active ingredient of the biological pesticide is compounded by polyhedrosis virus and rhein, and the mass ratio of the polyhedrosis virus to rhein is 1-19:39-1; Wherein, the polyhedrosis virus is 200 billion PIB / g of Spodoptera exigua nuclear polyhedrosis virus.

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