Ultra-low volume liquid for preventing and treating spodoptera frugiperda

Abstract

The invention belongs to the technical field of ultra-low volume liquid, and particularly relates to ultra-low volume liquid for preventing and treating spodoptera frugiperda. The ultra-low volume liquid for preventing and treating the spodoptera frugiperda is prepared from the following components in percentage by mass: 8 to 20 percent of an active component, 0.5 to 1.5 percent of a synergist, 5 to 8 percent of a cosolvent, 3 to 5 percent of a penetrating agent, 2 to 3 percent of a dispersing agent, 0.5 to 1 percent of an antioxidant, 0.3 to 0.5 percent of an anti-drifting agent and the balance of a solvent, wherein the active ingredient is prepared by compounding abamectin and lufenuron. The synergist of the ultra-low volume liquid can enhance the toxicity effect of the compound combination, and is beneficial to further improving the control effect on target pests. In addition, compared with a single penetrant, the penetrant of the ultra-low volume liquid can improve the wetting, spreading and infiltration capacities of the agent, so that the utilization rate of effective components of pesticides is improved, the pesticide dosage is reduced, and the environmental pollution and the prevention and treatment cost are reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of ultra-low volume liquid agents, and particularly relates to an ultra-low volume liquid agent for controlling Spodoptera frugiperda. Background Art

[0002] Spodoptera frugiperda belongs to the genus Spodoptera of the family Noctuidae in the order Lepidoptera, and is a polyphagous agricultural pest with characteristics such as strong migratory ability, fast reproduction speed, and wide host range. It was officially listed in the first-class pest list in China in 2020. In sugarcane production, the 1st to 3rd instar larvae of Spodoptera frugiperda damage the heart leaves of sugarcane seedlings, feed on the mesophyll, and leave typical semi-transparent "window holes". The larvae above the 3rd instar can chew the leaves into holes and notches, or bite off the growing points, affecting the normal growth of sugarcane plants and resulting in a reduction in sugarcane yield.

[0003] In sugarcane production, the damage of Spodoptera frugiperda can be controlled by spraying insecticides such as abamectin, chlorantraniliprole, lufenuron, chlorfenapyr, spinetoram, chlorantraniliprole, and flubendiamide. However, the continuous and repeated use of a single insecticide will cause Spodoptera frugiperda to quickly develop drug resistance, and the genetic drug resistance will spread rapidly in different regions with its migratory habits, not only resulting in a reduction in the efficacy of the drug, but also leading to excessive pesticide residues and increased environmental pollution.

[0004] The compounding of different insecticidal active ingredients is one of the effective and convenient ways to effectively alleviate pest drug resistance. In the prior art, the compounding of abamectin and lufenuron has been reported. For example, the patent of CN100353840C discloses that when lufenuron is compounded with abamectin or emamectin benzoate, it can produce a synergistic effect, overcome and delay pest drug resistance, expand the control spectrum, reduce the drug use cost, and can control the larvae of Lepidoptera pests and mites occurring in crop production, especially can be used to control Spodoptera exigua, and the effect is significantly higher than its single agent. In addition, the patent of CN111165479A discloses an abamectin and lufenuron synergistic suspension agent and its preparation method, which uses abamectin and lufenuron as active ingredients, supplemented with emulsifiers, dispersants, antioxidants, etc. as auxiliary ingredients to prepare a synergistic suspension agent containing abamectin and lufenuron.

[0005] Ultra-low volume liquid agents are a type of high-efficiency pesticide dosage form that emerged with the appearance of ultra-low volume spraying equipment. The core lies in the extremely low application rate and high-concentration active ingredients, which can be directly sprayed without dilution, effectively reducing the consumption of water resources and transportation costs. In addition, the droplets are tiny and uniform, forming a fine fog cloud through special spraying equipment, covering the crops more evenly, quickly responding to pest damage, and reducing the loss of liquid medicine. Based on this, it is of great significance to develop a compound combination of abamectin and lufenuron into an ultra-low volume liquid agent.

[0006] There have been no reports on the development of an ultra-low volume liquid formulation by combining abamectin and lufenuron.

[0007] The information disclosed in this background section is only intended to enhance the overall understanding of the present invention and should not be regarded as an admission or any form of suggestion that this information constitutes prior art already known to those of ordinary skill in the art. Summary of the Invention

[0008] The object of the present invention is to provide an ultra-low volume liquid formulation for controlling Spodoptera frugiperda, which has excellent wetting, spreading and penetration capabilities, can improve the utilization rate of the active ingredients of pesticides, reduce the amount of pesticides used, and reduce environmental pollution and control costs.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] An ultra-low volume liquid formulation for controlling Spodoptera frugiperda, calculated by mass percentage, is prepared from the following components: 8-20% active ingredient, 0.5-1.5% synergist, 5-8% cosolvent, 3-5% penetrant, 2-3% dispersant, 0.5-1% antioxidant, 0.3-0.5% anti-drift agent, and the solvent is supplemented to 100%; wherein, the active ingredient is composed of a compound of abamectin and lufenuron.

[0011] Further, the compound mass ratio of abamectin to lufenuron is 1-2:6-1.

[0012] Further, the synergist is farnesol, and the mass ratio of abamectin, lufenuron and farnesol is 2:8:1.

[0013] Further, the cosolvent is dimethyl sulfoxide.

[0014] Further, the penetrant is composed of alkyl polyglycoside APG-0810 and castor oil polyoxyethylene ether EL-40 in a mass ratio of 2-3:1.

[0015] Further, the dispersant is sodium lignosulfonate.

[0016] Further, the antioxidant is 2,6-di-tert-butyl-p-cresol.

[0017] Further, the anti-drift agent is polyvinyl alcohol BP-05.

[0018] Further, the solvent is methyl oleate.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) The ultra-low volume liquid agent of the present invention selects farnesol as a synergist for the compound combination of abamectin and lufenuron. It can enhance the virulence of the compound combination and help further improve the control effect on target pests.

[0021] (2) The ultra-low volume liquid agent of the present invention selects the combination of alkyl polyglycoside and castor oil polyoxyethylene ether as a penetrant. Compared with a single penetrant, it can improve the wetting, spreading and penetration ability of the medicament, thereby improving the utilization rate of the active ingredient of the pesticide, reducing the dosage of the pesticide, and reducing environmental pollution and control costs. Detailed implementation manners

[0022] The technical solutions of the present invention patent will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative work belong to the scope protected by the present invention.

[0023] 1. Influence of synergist on the virulence of active ingredients

[0024] 1.1 Tested medicaments

[0025] 97% abamectin technical, 98% lufenuron technical, 95% farnesol. The above medicaments are all commercially available.

[0026] The tested medicaments were dissolved in dimethyl sulfoxide and diluted with 0.1% Tween-80 aqueous solution to prepare single-agent mother liquors. Multiple groups of ratios were set. Each single-agent mother liquor and the mixture of each group ratio were further diluted with 0.1% Tween-80 aqueous solution into 5 mass concentration gradients.

[0027] 1.2 Tested pests

[0028] The larvae of Spodoptera frugiperda in sugarcane planting fields were collected. After being continuously reared for 6 generations in the laboratory, the 3rd instar larvae with the same body size were selected as the tested pests. Rearing conditions: temperature 28 ± 1 °C, photoperiod 14L / 10D, relative humidity 75%; the larvae were fed with fresh and clean sugarcane leaves, and the adults were fed with 10% honey water.

[0029] 1.3 Test methods

[0030] The leaf dipping method was adopted. The fresh and clean sugarcane leaves were cut into sections, immersed in the liquid medicine for 15 s and then taken out, dried, placed in a petri dish containing wet filter paper, and the tested pests starved for 4 h were introduced. 5 pests were introduced into each petri dish. Each liquid medicine treatment was set with 3 replicates, and each replicate had 4 petri dishes (i.e., 20 tested pests for each replicate), and the treatment with 0.1% Tween-80 aqueous solution was set as the blank control.

[0031] Transfer to the conditions of temperature 28±1°C, photoperiod 14L / 10D, and relative humidity 75%, observe, investigate the death of pests after 48h, record the total number of pests and the number of dead pests in each treatment, and calculate the corrected mortality of each treatment. Among them, those that do not move when the body surface of the tested pests is gently touched with a writing brush are regarded as dead.

[0032]

[0033] In the above formula: P--mortality rate, unit: %; K--number of dead pests; N--total number of pests in the treatment.

[0034]

[0035] In the above formula: P1--corrected mortality rate, unit: %; P t --mortality rate of the treatment, unit: %; P0--mortality rate of the blank control, unit: %.

[0036] 1.4 Data analysis

[0037] Conduct a regression analysis on the logarithm of the chemical concentration and the probit value of the corrected mortality rate to obtain the regression equation and LD of different chemical treatments 50 , calculate the co-toxicity coefficient of the mixture by the Sun Yunpei method, and evaluate the action type: CTC≤80 is antagonistic action, 80<CTC<120 is additive action, CTC≥120 is synergistic action, and the results are shown in Table 1.

[0038]

[0039] In the above formula: ATI--actual toxicity index of the mixture; S--ED of the standard chemical 50 , unit: g a.i. / hm 2 ; M--ED of the tested chemical 50 , unit: g a.i.hm 2 .

[0040] TTI = TI A ×P A +TI B ×P B

[0041] In the above formula: ITI--theoretical toxicological index of the mixture; TI A --toxicity index of chemical A; P A --percentage content of chemical A in the mixture, unit: percentage (%) ; II B --toxicity index of chemical B; P B --percentage content of chemical B in the mixture, unit: percentage (%).

[0042]

[0043] In the above formula: CTC--coefficient of co-toxicity; ATI--actual toxicity index of the mixture; TTI--theoretical toxicity index of the mixture.

[0044] Table 1 Influence of synergists on the toxicity of active ingredients

[0045]

[0046] As can be seen from Table 1, the LC 50 of abamectin, lufenuron and farnesol against the 3rd instar larvae of Spodoptera frugiperda was 8.652 mg / L, 32.493 mg / L and 102.974 mg / L respectively. When they were compounded, when the mass ratio of abamectin to lufenuron was 2:8, the compound combination showed a synergistic effect; when the mass ratio of abamectin to farnesol was 2:1 and the mass ratio of lufenuron to farnesol was 8:1, the compound combinations all showed an additive effect; when the mass ratio of abamectin, lufenuron and farnesol was 2:8:1, the compound combination showed a synergistic effect, and the co-toxicity coefficient value was greater than that of the compound of abamectin and lufenuron at a mass ratio of 8:1. This shows that when farnesol is used as a synergist for the compound combination of abamectin and lufenuron, farnesol can enhance the toxicity of the compound combination and help improve the control effect on target pests.

[0047] 2. Influence of penetrants on the performance of pesticides

[0048] 2.1 Ultra-low volume liquid formulation

[0049] See Table 2.

[0050] Table 2 Ultra-low volume liquid formulation

[0051]

[0052]

[0053] Preparation method: Methyl oleate and dimethyl sulfoxide are mixed and heated to 45 °C. After stirring and dissolving, abamectin technical and lufenuron technical are added in sequence. The temperature is maintained and stirred until the technical is completely dissolved. After cooling to room temperature, the remaining components are added, and high-speed shearing is carried out at 8000 rpm for 30 min, and then filtered through a 50 μm filter membrane to obtain the ultra-low volume liquid.

[0054] 2.2 Influence of different penetrants on the performance of pesticides

[0055] The surface tension, contact angle on the surface of sugarcane leaves and deposition amount on the surface of sugarcane leaves of the ultra-low volume liquid in Table 2 were measured respectively.

[0056] The surface tension of the liquid agent was measured by the hanging drop method (Young-Laplace equation): The liquid medicine was made into a hanging drop, and a surface tensiometer was used to measure the surface tension of the liquid medicine, calculate the surface tension value (mN / m), measure 5 times repeatedly, and take the average value.

[0057] The contact angle was measured using a contact angle measuring instrument: The liquid medicine was dropped on the surface of sugarcane leaves, and the initial contact angle after the liquid drop contacted the surface and the equilibrium contact angle after full spreading were recorded. 10 samples were measured for each treatment, and the average value was taken.

[0058] After weighing the sugarcane leaves, they were placed horizontally, and the liquid medicine was evenly sprayed. After the solvent evaporated, the sugarcane leaves were weighed again, and the residual amount of the liquid medicine per unit area (mg / cm 2 ) was measured by the weighing method.

[0059] The results are shown in Table 3.

[0060] Table 3 Effects of different penetrants on the properties of the medicament

[0061]

[0062] As can be seen from Table 3, in terms of surface tension, after adding the penetrant, the surface tension of the ultra-low volume liquid agent decreased, and the penetrant composed of alkyl polyglycoside APG-0810 and castor oil polyoxyethylene ether EL-40 decreased significantly. The decrease in surface tension can enhance the wetting ability of the medicament, indicating that the penetrant of the present invention enhances the wetting ability of the medicament;

[0063] In terms of the contact angle, after adding the penetrant, the initial contact angle and the equilibrium contact angle of the ultra-low volume liquid agent both decreased, and the penetrant composed of alkyl polyglycoside APG-0810 and castor oil polyoxyethylene ether EL-40 had the most significant effect. The decrease in the contact angle helps to enhance the spreading ability of the medicament, which indicates that the penetrant of the present invention enhances the spreading ability of the medicament;

[0064] In terms of the deposition amount, after adding the penetrant, the deposition amount of the ultra-low volume liquid agent increased, and the penetrant composed of alkyl polyglycoside APG-0810 and castor oil polyoxyethylene ether EL-40 had the most significant effect. Increasing the deposition amount of the liquid medicine can improve the utilization rate of the effective ingredients of the pesticide, which indicates that the penetrant of the present invention enhances the deposition amount of the liquid medicine, helps to improve the utilization rate of the effective ingredients of the pesticide, reduces the amount of pesticide used, and reduces environmental pollution and control costs.

[0065] 3. Field test

[0066] A randomized block design was adopted, and each plot was 50m 2, a plant protection UAV was used to fly and spray the ultra-low volume liquid agent in Table 2. Each liquid medicine was repeated 4 times, and spraying equal amount of clear water was set as the blank control. Before applying the medicine, the number of Spodoptera frugiperda larvae on the sugarcane plants was investigated, and the number of surviving Spodoptera frugiperda larvae on the sugarcane plants was investigated on the 7th day after applying the medicine. In each plot, the 5-point sampling method was used for sampling and investigation. 5 sugarcane plants were investigated at each point, and the number of live insects was investigated at fixed points and fixed plants. According to the investigation results, the reduction rate of insect population and the control effect were calculated. The results are shown in Table 4.

[0067]

[0068] Table 4 Field control effects of different ultra-low volume liquid agents on Spodoptera frugiperda larvae

[0069]

[0070] As can be seen from Table 4, the control effect of the ultra-low volume liquid agent of Formula 4 was 76.39%, which was significantly better than that of the ultra-low volume liquid agents of Formulas 1-3, indicating that the ultra-low volume liquid agent of the present invention has excellent control effect on Spodoptera frugiperda.

[0071] In summary, the ultra-low volume liquid agent of the present invention selects farnesol as the synergist for the compound combination of abamectin and lufenuron, which can enhance the virulence of the compound combination and help to further improve the control effect on target pests. In addition, the ultra-low volume liquid agent of the present invention selects the combination of alkyl glycoside and castor oil polyoxyethylene ether as the penetrant. Compared with a single penetrant, it can improve the wetting, spreading and penetration ability of the medicine, thereby improving the utilization rate of the effective ingredient of the pesticide, reducing the dosage of the pesticide, and reducing environmental pollution and control costs.

[0072] The foregoing description of specific exemplary embodiments of the present invention is for purposes of illustration and exemplification. These descriptions are not intended to limit the present invention to the precise forms disclosed, and obviously, many changes and variations are possible in light of 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 applications, so that those skilled in the art can implement and utilize various different exemplary embodiments of the present invention, as well as various different selections and changes. The scope of the present invention is intended to be defined by the claims and their equivalents.

Claims

1. An ultra-low volume liquid agent for controlling Spodoptera frugiperda, characterized in that, The ultra-low volume liquid agent for controlling Spodoptera frugiperda is prepared from the following components by mass percentage: 8-20% active ingredient, 0.5-1.5% synergist, 5-8% cosolvent, 3-5% penetrant, 2-3% dispersant, 0.5-1% antioxidant, 0.3-0.5% anti-drift agent, and the solvent is supplemented to 100%; wherein, the active ingredient is a compound of abamectin and lufenuron.

2. The ultra-low volume liquid agent for controlling Spodoptera frugiperda according to claim 1, wherein The compounding mass ratio of abamectin and lufenuron is 1-2:6-1.

3. The ultra-low volume liquid agent for controlling Spodoptera frugiperda according to claim 1, wherein, The synergist is farnesol; the mass ratio of abamectin, lufenuron and farnesol is 2:8:

1.

4. The ultra-low volume liquid agent for controlling Spodoptera frugiperda according to claim 1, characterized in that, The cosolvent is dimethyl sulfoxide.

5. The ultra-low volume liquid agent for preventing and controlling Spodoptera frugiperda according to claim 1, wherein The penetrant is composed of alkyl polyglycoside APG-0810 and castor oil polyoxyethylene ether EL-40 according to a mass ratio of 2-3:

1.

6. The ultra-low volume liquid agent for controlling Spodoptera frugiperda according to claim 1, characterized in that, The dispersant is sodium lignosulfonate.

7. The ultra-low volume liquid agent for preventing and controlling Spodoptera frugiperda according to claim 1, wherein The antioxidant is 2,6-di-tert-butyl-p-cresol.

8. The ultra-low volume liquid agent for preventing and controlling Spodoptera frugiperda according to claim 1, characterized in that, The anti-drift agent is polyvinyl alcohol BP-05.

9. The ultra-low volume liquid agent for preventing and controlling Spodoptera frugiperda according to claim 1, wherein, The solvent is methyl oleate.

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