Insecticide and acaricide composition for preventing and controlling cassava red spider

Abstract

The present invention belongs to the technical field of pesticide research and development, and specifically relates to an insecticidal and acaricidal composition for preventing and controlling cassava red spiders. An insecticidal and acaricidal composition for preventing and controlling cassava red spiders, wherein the effective component is a binary compound of ethazofop-butyl and rotenone or pyrimethoxam. When ethazofop-butyl and rotenone or pyrimethoxam in the insecticidal and acaricidal composition of the present invention are compounded, the biological activity of cassava red spiders within a certain mass ratio range is synergistic, and compared with a single effective component, the control effect on cassava red spiders can be improved, the application amount of pesticides can be reduced, and the cost can be reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of pesticide research and development, and particularly relates to an insecticide and acaricide composition for preventing and controlling cassava red spiders. Background Art

[0002] Cassava is one of the three major tuber crops in the world, widely grown in tropical and subtropical regions. Mites are the main pests of cassava, among which red spider mites are the most serious. Red spider mites mainly damage cassava leaves by gathering on the back of the leaves to suck juice. It is reported that the damage of cassava by red spider mites can lead to a 10-30% reduction in local cassava production, and in severe cases, it can reach 50-70%.

[0003] In the agricultural production process, chemical agents are a common method for preventing and controlling cassava spider mites. Currently, the most commonly used chemical agents include 15% pyraclostrobin EC, 73% propargite EC and 20% amitraz EC. In recent years, due to the long-term continuous use of chemical agents and unscientific use of drugs, pesticide resistance and environmental problems have become increasingly serious. In particular, cassava spider mites have a fast reproduction rate and overlapping generations, making them very easy to develop resistance. It is necessary to find new control strategies to solve the above problems.

[0004] Shenyang Sinochem Pesticide Chemical Research and Development Co., Ltd. used cypermethrin as the lead compound and discovered the compound ethoxyfenil with high acaricidal activity by modifying the pyrazole ring and hydroxyl part in its structure. Ethoxyfenil has outstanding rapid effect, and can achieve extremely high mortality in 1-3 days. It has excellent effects on the four insect stages of red spider mites, and is safe for crops and environmentally friendly.

[0005] Rotenone is an insecticidal active substance isolated from the root of the insecticidal plant Rotenone. Rotenone and rotenone have toxic, anti-feedant, growth and development interference and egg-preventing effects on insects. It is reported that the insecticidal activity of rotenone varies with the insect species. Its activity against citrus mites, diamondback moth and yellow flea beetle is comparable to rotenone. Its LC 50 There was no significant difference, but the activity against cabbage aphid and pastel disc was significantly lower than rotenone.

[0006] Bifenthrin is a neonicotinoid insecticide developed jointly by Kesheng Group and East China University of Science and Technology. Its insecticidal mechanism mainly acts on the axon receptors of insect nerves to block nerve conduction. Bifenthrin has a good systemic conduction function, which means that the agent can be quickly transmitted to various parts of the plant. It has the characteristics of fast insecticidal speed, high control effect, long-lasting effect, spectrum and low toxicity for various piercing-sucking pests.

[0007] Reasonable compounding of chemical agents has the characteristics of expanding the insecticide spectrum, improving the control effect, delaying the development of pest resistance, reducing the amount of application and pesticide residues, etc. The inventors found through indoor experiments that compounding ethozofen with rotenone or pyraclostrobin showed a synergistic effect on the control of cassava red spider mites.

[0008] At present, there are no reports on the combination of ethidium bromide with rotenone or pyraclostrobin. Summary of the invention

[0009] The object of the present invention is to provide an insecticide and acaricide composition for controlling cassava red spiders, so as to solve the increasingly serious pesticide resistance and environmental problems caused by the long-term continuous use of chemical agents and unscientific use of pesticides, especially the problem that cassava red spiders reproduce quickly and overlap generations, making them very easy to develop resistance.

[0010] To achieve the above object, the present invention provides the following technical solutions:

[0011] The first object of the present invention is to provide an insecticidal and acaricidal composition for controlling cassava red spiders, wherein the active ingredients are a binary compound of ethidium bromide and rotenone or pyrimethamine.

[0012] Preferably, the mass ratio of ethidium bromide to rotenone is 1-39:15-1.

[0013] Preferably, the mass ratio of ethidium bromide to cypermethrin is 1-17:20-1.

[0014] The second object of the present invention is to provide an insecticide and acaricide, which is prepared by using the insecticide and acaricide composition for controlling cassava red spider as an active ingredient and supplemented with auxiliary agents allowed to be added in pesticide science.

[0015] Preferably, the insecticide and acaricide is in the form of an aqueous emulsion, a suspension, a wettable powder or a water dispersible granule.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] (1) When the ethidium aconitum in the insecticidal and acaricidal composition of the present invention is compounded with rotenone or pyrimethamine, the biological activity of the cassava red spider mites is synergistic within a certain mass ratio range. Compared with a single active ingredient, the control effect on the cassava red spider mites can be improved, the application amount of pesticides can be reduced, and the cost can be reduced.

[0018] (2) The mechanism of action of ethidium bromide in the insecticidal and acaricidal composition of the present invention is different from that of rotenone or pyrimethamine, which can effectively delay the development of insecticide resistance in pests and reduce the risk of insecticide resistance caused by the use of a single active ingredient alone. To a certain extent, it can play a certain protective role on the insecticidal and acaricidal composition. DETAILED DESCRIPTION

[0019] The present invention may be better understood according to the following embodiments. The contents described in the embodiments are only used to illustrate the present invention, and should not and will not limit the present invention described in detail in the claims.

[0020] Example :Indoor biological activity test of ethazolinyl compound

[0021] 1. Test subjects: Cassava red spiders were collected from cassava planting areas, and were raised on fresh cassava leaves in the laboratory for a period of time. Female adult cassava red spiders of uniform size, health and vitality were selected as test subjects.

[0022] 2. Test reagents

[0023] 98% ethazolinyl technical (Shenyang Kechuang Chemicals Co., Ltd.);

[0024] 93.5% drotenone technical drug (made in the laboratory, extracted from the roots of drotenone according to the method of Zeng Xinnian et al. (2002));

[0025] 95% bispyribac technical (Jiangsu Kesheng Crop Science and Technology Co., Ltd.);

[0026] The original drug was first dissolved in dimethyl sulfoxide to prepare a single-dose stock solution, and then diluted with a 0.1% Tween-80 aqueous solution. Multiple groups of proportions were set up, and each single dose and each group of mixed proportions were set with 5 mass concentration gradients according to the equal ratio method for standby use.

[0027] 3. Test method (refer to "NT / T 1154.13-2008 Pesticide Indoor Test Guidelines Insecticides Part 13: Leaf Disk Spray Method")

[0028] Select fresh cassava leaves and make leaf discs with a hole puncher; place a wet sponge block in a 9cm diameter culture dish, put filter paper on it, and put leaf discs on the filter paper, with 2 leaf discs per dish; inoculate the test pests on the leaf discs, with 20 inoculated on each leaf disc. Place the culture dish on the bottom plate of the Potter spray tower for spraying, with a spray volume of 1mL, and repeat each treatment 4 times, and set a treatment containing only 0.1% Tween-80 aqueous solution as a blank control; take out the solution after it sinks for 1min, and transfer it to a temperature of (25±1)℃ and a light cycle of L:D=(16:8)h for breeding. Observe the death of the pest mites 48h after treatment (touch the appendages of the pest mites with a soft brush, and it is judged as dead if it does not move), record the total number of insects and the number of dead insects in each treatment, and calculate the corrected mortality rate of each treatment.

[0029]

[0030] In the above formula: P--mortality rate, unit is %; K--number of dead insects; N--total number of insects treated.

[0031]

[0032] In the above formula: P1--corrected mortality rate, unit is %; P t --Treatment mortality rate, in %; P0--blank control mortality rate, in %.

[0033] 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.

[0034]

[0035] In the above formula: ATI--the toxicity index of the mixture; S--the LC of the standard agent 50 , the unit is mg / L; M--LC of the mixture 50 , unit is mg / L.

[0036] TTI=TI A ×P A +TI B ×P B

[0037] In the above formula: TTI-theoretical toxicity index of the mixture; TI A --Toxicity index of A agent; P A --The percentage of agent A in the mixture, in percentage (%); TI B --Toxicity index of agent B; P B --The percentage of agent B in the mixture, in percentage (%).

[0038]

[0039] In the above formula: CTC--co-toxicity coefficient; ATI--actual toxicity index of the mixture; TTI--theoretical toxicity index of the mixture.

[0040] 5. Efficacy evaluation

[0041] 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.

[0042] Table 1 Indoor biological activity determination of the combination of ethazolin and rotenone against cassava spider mites

[0043] Drug name and ratio <![CDATA[LC 50 (mg / L)]]> ATI TTI CTC Ethiophanate-methyl 1.71 100.00 -- -- Rotenone 9.39 18.21 -- -- Ethiocarb 1: Rotenone 15 5.89 29.03 23.32 124.48 Ethiocarb 1: Rotenone 7 3.08 55.52 28.43 195.25 Ethiocarb 1: Rotenone 5 2.03 84.24 31.84 264.54 Ethiocarb 1: Rotenone 3 1.05 162.86 38.66 421.28 Ethiocarb 1: Rotenone 1 1.43 119.58 59.11 202.32 Ethiocarb 3: Rotenone 1 1.64 104.27 79.55 131.07 Ethiocarb 5: Rotenone 1 0.86 198.84 86.37 230.22 Ethiophanate-methyl 7: Rotenone-1 1.38 123.91 89.78 138.02 Ethiocarb 15: Rotenone 1 0.77 222.08 94.89 234.04 Ethiocarb 30: Rotenone 1 0.48 356.25 97.36 365.90 Ethiocarb 39: Rotenone 1 0.92 185.87 97.96 189.75

[0044] As shown in Table 1, within the mass ratio of 1-39:15-1, the co-toxicity coefficient of ethidium bromide and rotenone for controlling cassava red spider mites is greater than 120, that is, the biological activity against cassava red spider mites shows a synergistic effect.

[0045] Table 2 Indoor biological activity determination of ethazolin and pyraclostrobin against cassava spider mites

[0046] Drug name and ratio <![CDATA[LC 50 (mg / L)]]> ATI TTI CTC Ethiophanate-methyl 1.71 100.00 -- -- Bifenthrin 24.37 7.02 -- -- Ethiophanate-methyl 1: pyraclostrobin 20 11.92 14.35 11.44 125.35 Ethiocarb 1: Bifenthrin 15 9.57 17.87 12.83 139.29 Ethiophanate-methyl 1: Bifenthrin-7 4.93 34.69 18.64 186.08 Ethiocarb 1: Bifenthrin 5 3.12 54.81 22.51 243.44 Ethiocarb 1: Bifenthrin 3 2.08 82.21 30.26 271.66 Ethiophanate-methyl 1: Bifenthrin-1 0.97 176.29 53.51 329.46 Ethiocarb 3: Bifenthrin 1 0.41 417.07 76.75 543.39 Ethiocarb 5: Bifenthrin 1 0.36 475.00 84.50 562.11 Ethiocarb 7: Bifenthrin 1 0.55 310.91 88.38 351.80 Ethiophanate-methyl 17: Bifenthrin-1 1.18 144.92 94.83 152.81

[0047] As shown in Table 2, within the mass ratio of 1-17:20-1, the co-toxicity coefficient of ethidium bromide and cypermethrin for the control of cassava red spider mites is greater than 120, that is, the biological activity against cassava red spider mites shows a synergistic effect.

[0048] In summary, when ethidium bromide in the insecticidal and acaricidal composition of the present invention is compounded with rotenone or pyrimethamine, the biological activity of cassava red spider mites is synergistic within a certain mass ratio range. Compared with a single active ingredient, the control effect on cassava red spider mites can be improved, the application amount of pesticides can be reduced, and the development of pest resistance can be delayed.

[0049] The above is only a preferred embodiment of the present invention. Those skilled in the art may make appropriate improvements without departing from the principle of the present invention. These improvements are also within the protection scope of the present invention.

Claims

1. An insecticidal and acaricidal composition for controlling cassava red spider, characterized in that: The effective component is prepared by compounding ethidium cypermethrin and rotenone, and the mass ratio of ethidium cypermethrin to rotenone is 1-39:15-1.

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