Microemulsion containing abamectin and flonicamid

Abstract

The invention relates to the technical field of pesticides, in particular to a microemulsion containing abamectin and flonicamid. The flonicamid and abamectin compounded suspending agent is prepared from a flonicamid active compound, an abamectin active compound, a solvent, a coupling agent, an emulsifier, a synergistic aid and deionized water. The environment-friendly solvent is used, pollution to the environment is avoided, the ecological toxicity is low, the oil-water interface compatibility can be effectively improved, and the contact angle is reduced. Meanwhile, the microemulsion prepared by the invention is high in stability and long in lasting period, and can meet field requirements under complex climate conditions.

Description

Technical Field

[0001] This application relates to the field of pesticide technology, and more specifically, to a microemulsion containing abamectin and flonicamid. Background Technology

[0002] Aphids are common pests in agricultural production, characterized by short reproductive cycles, high reproduction rates, and significant generational overlap, making them prone to developing pesticide resistance. While many targeted insecticides are available on the market, aphids have developed strong resistance to common pesticides due to years of heavy use. With the increasing prominence of pesticide pollution problems and growing public concern about the environment, seeking to reduce the risks associated with pesticides and their use through innovation in formulation technology has become a hot topic in the field of pesticide formulation.

[0003] Avermectins are a sixteen-membered macrocyclic lactone compound developed by a team led by Satoshi Ōmura at Kitasato University, Japan, in collaboration with Merck, Inc. They are produced by fermentation from *Streptomyces avermitilis*. In its natural state, this compound contains eight homologues, with the main components A1a, A2a, B1a, and B2a comprising ≥80%, and the minor components A1b, A2b, B1b, and B2b comprising ≤20%. As a typical microbial insecticide, its mechanism of action is unique: it stimulates the release of γ-aminobutyric acid (GABA) from pests, interfering with nerve conduction and ultimately leading to paralysis and death of adult mites, nymphs, and insect larvae. This agent has both stomach poison and contact effects but no ovicidal activity; it is easily degraded by microorganisms in soil, with minimal impact on beneficial insects; the water-soluble formulation can be directly diluted for use, making it suitable for integrated pest management systems.

[0004] Flupyradifurone (molecular formula: C9H6F3N3O) is a pyridine amide insect growth regulator registered in China in 2007, and its 10% water-dispersible granule formulation has been industrialized. As a novel environmentally friendly insecticide, in addition to contact and stomach poison effects, it also has neurotoxicity and rapid antifeeding effects; piercing-sucking pests stop excreting within one hour after feeding and eventually die of starvation; it conforms to the modern trend of low-toxicity pesticide development and is particularly suitable for resistance management.

[0005] Currently, most avermectin and flupyradifurone on the market are in emulsifiable concentrate form, which not only has high product cost and poor efficacy, but also causes serious environmental pollution and excessive waste of resources during product use.

[0006] Market data from 2024 shows that microemulsions accounted for 27% of high-end pesticide formulations. Their characteristics include using water as a medium, containing little or no organic solvents, thus being non-flammable and non-explosive, safe in production, storage, and transportation, with less environmental pollution, and saving significant amounts of organic solvents; extremely high pesticide dispersibility, reaching a micronized level, with an appearance similar to a transparent or semi-transparent liquid; good dispersibility in water, strong penetration into the target, and high adhesion.

[0007] Patent CN107087632A discloses a microemulsion of flupyridine and avermectin B2a. This microemulsion uses N-methylpyrrolidone or cyclohexanone as a solvent, and the emulsification system is complex, increasing the formulation cost, requiring frequent application, and potentially posing environmental residue risks.

[0008] Patent CN101700024A discloses a microemulsion of flupyradifurone and abamectin, which uses xylene and dimethylformamide as solvents, posing potential hazards to humans and the environment. Summary of the Invention

[0009] As pesticide formulations evolve towards higher efficiency and environmental friendliness, the purpose of this invention is to address the shortcomings of existing technologies by providing a microemulsion containing flupyradifurone and abamectin that is low in toxicity and highly penetrative. By screening solvents, the safety, stability, and duration of effectiveness of the formulation can be further improved to meet the needs of field operations under complex climatic conditions.

[0010] To achieve the above objectives, the technical content disclosed in this invention is as follows: The microemulsion containing flupyradifurone and abamectin provided by this invention is made from the following raw materials in weight percentage: 5-20% flupyradifurone technical grade, 1-10% abamectin technical grade, 15-35% solvent, 1-15% coupling agent, 10-30% emulsifier, 0.1-1% synergist, and deionized water to make up to 100%.

[0011] Preferably, the microemulsion containing flupyradifurone and abamectin is made from the following raw materials in weight percentage: 10-15% flupyradifurone technical grade, 1-5% abamectin technical grade, 20-30% solvent, 8-15% coupling agent, 15-25% emulsifier, 0.1-1% synergist, and deionized water to make up to 100%.

[0012] The solvent is selected from one or more of methylated soybean oil, PEG-400, propylene glycol methyl ether, fatty acid methyl ester, methyltetrahydrofuran, N-methylpyrrolidone, ethanol, acetone, glacial acetic acid, α-terpineol, glucamide, and sorbitol.

[0013] The coupling agent is selected from one or more of the following: decanoamide, ethylene oxide soybean oil, alkyl polysaccharide, and dipropylene glycol methyl ether.

[0014] The emulsifier is selected from one or more of the following: benzyl dimethylphenol polyoxyethylene ether, tristyryl phenol polyoxyethylene ether, styryl phenyl polyoxyethylene ether, phenethyl phenol polyoxyethylene polyoxypropylene ether, lignin sulfonate, naphthalene sulfonate formaldehyde condensate, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, calcium dodecylbenzene sulfonate, castor oil polyoxyethylene ether, nonylphenol polyoxyethylene ether, alkylphenol formaldehyde resin polyoxyethylene ether, polyoxyethylene sorbitan fatty acid ester, fatty alcohol polyoxyethylene ether, polyoxyethylene alkyl ether, nonylphenol polyoxyethylene ether phosphate, phenylphenol polyoxyethylene ether phosphate, dehydrated sorbitan monostearate polyoxyethylene ether, styrene polyoxyethylene ether ammonium sulfate, sorbitan anhydride monostearate, and dehydrated sorbitan fatty acid ester polyoxyethylene ether.

[0015] The synergistic agent is selected from one or more of organosilicon compounds, xanthan gum, polyether-modified siloxanes, and polyvinylpyrrolidone.

[0016] Preferably, the solvent is a mixture of fatty acid methyl ester and methyltetrahydrofuran.

[0017] Preferably, the coupling agent is decanoamide.

[0018] Preferably, the emulsifier is a composition of tristyrylphenol polyoxyethylene ether, castor oil polyoxyethylene ether, and calcium dodecylbenzenesulfonate.

[0019] Preferably, the synergistic agent is an organosilicon or xanthan gum.

[0020] Preferably, the ratio of fatty acid methyl ester to methyltetrahydrofuran is 1-10:1-5 by mass. Preferably, the ratio of tristyrylphenol polyoxyethylene ether, castor oil polyoxyethylene ether, and calcium dodecylbenzenesulfonate is 1-5:1-5:1-5 by mass. The solvents used in this invention, fatty acid methyl ester and methyltetrahydrofuran, are bio-based green solvents, improving environmental friendliness and causing no harm to animals, plants, or the environment. Production costs are reduced by 30% in solvent usage. Another objective of this invention is to provide a method for preparing and applying the above-mentioned microemulsion containing flupyradifurone and avermectin, the preparation steps of which are as follows: Add the solvent, coupling agent, and synergist to the preparation axe and start stirring. Add the flupyradifurone technical and abamectin technical, and stir for 30 minutes to dissolve and mix. Continue to add the emulsifier, stir for 50 minutes to mix evenly, then add the remaining deionized water, shear for 20 minutes, mix evenly, filter after passing the test, and after settling for 12 hours, package to obtain the product.

[0021] This invention provides the application of the above-mentioned microemulsion containing flupyradifurone and abamectin in the control of crop pests.

[0022] The crop pests and diseases mentioned include: aphids on cotton, greenhouse vegetables, and fruit trees; whiteflies / tobacco whiteflies on tomatoes, cucumbers, and peppers; thrips on flowers, legumes, and solanaceous crops; and psyllids throughout the entire growth period of citrus fruits.

[0023] By adopting the above technical solution, the present invention has the following beneficial effects: 1. This invention uses a green solvent that is environmentally friendly, has low ecotoxicity, and can effectively improve oil-water interface compatibility, reduce contact angle, and improve permeability.

[0024] 2. The microemulsion prepared by this invention has high stability and long duration of action, which can meet the field requirements under complex climatic conditions. Detailed Implementation

[0025] The present invention will be further described below with reference to embodiments, but the present invention is not limited thereto.

[0026] All reagents used in the following embodiments of the present invention can be obtained commercially or in-house. The 95% avermectin technical grade was purchased from Hebei Weiyuan Biochemical Co., Ltd., and the 97% flonicamid technical grade was purchased from Shaanxi Nuozheng Biotechnology Co., Ltd. Unless otherwise specified, all percentages mentioned in the following embodiments are by mass. The following formulations were prepared according to the preparation method described in the invention.

[0027] Example 1: 6% Flupyradifurone·Avermectin Microemulsion

[0028] Example 2: 12% Flupyradifurone·Avermectin Microemulsion

[0029] Example 3: 20% Flupyradifurone·Avermectin Microemulsion

[0030] Example 4: 20% Flupyradifurone·Avermectin Microemulsion

[0031] Example 5: 26% Flupyradifurone·Avermectin Microemulsion

[0032] Comparative Examples 1-5

[0033] Test Example 1 Field efficacy trial of flupyradifurone·avermectin microemulsion against cucumber aphids Experimental subject: cucumber aphids Test reagents: Flupyradifurone-Avermectin microemulsion as described in Examples 1-5, and commercially available 10% Flupyradifurone suspension, 4% Avermectin-Acetamiprid microemulsion, and 24% Avermectin-Flupyradifurone suspension. Water was used as a blank control.

[0034] Experimental methods: The experiment was conducted in a cucumber field in Jianlin Village, Wangdian Town, Xiuzhou District, Jiaxing City, Zhejiang Province. During the peak season of cucumber aphid outbreak, a backpack sprayer was used for uniform spraying. Each plot was 40 square meters. The number of aphids was investigated before application and the number of live aphids was investigated 7 and 14 days after application. The aphid population reduction rate and control efficacy were calculated. The experimental results are shown in Table 1.

[0035]

[0036]

[0037] The efficacy results 7 days after application showed that treatments 1, 2, 3, 4, and 5 were significantly more effective than treatments 7 and 8. The efficacy results 14 days after application showed that treatments 1, 2, 3, 4, and 5 were significantly more effective than treatments 6, 7, and 8.

[0038] Table 1 Field efficacy test of flupyradifurone·avermectin microemulsion against cucumber aphids.

[0039] Test Example 2 Ecotoxicity testing Eight zebrafish were placed in 2L solutions of different formulation concentrations, with pure water as a blank control group. The median lethal concentration (LC50) of the zebrafish was determined after 96 hours. Different concentrations of the drug were applied to the mesothorax of bees using a drip method, and mortality was observed within 48 hours to calculate the median lethal dose (LD50). Using the OECD 423 stepwise dosing design, five dose groups (10 SD rats per group, half male and half female) were established. The drugs were administered orally (volume ≤10mL / kg), and mortality and toxic symptoms (tremors, salivation, etc.) were observed for 14 days to calculate the median lethal dose (LD50 mg / kg).

[0040] Typical symptoms of cucumber burn: Water-soaked patches appear on leaves (within 24 hours) → browning and necrosis (after 48 hours), and in severe cases, leaf margins curl and fall off (refer to GB / T 8321-2018 Guidelines for Field Efficacy Testing of Pesticides).

[0041] Grading standards:

[0042] Ecotoxicity of flunitrazepam-avermectin microemulsion was tested on cucumber, zebrafish, rat and bee.

[0043] Examples 1-5 showed low toxicity, low toxicity, and low risk in zebrafish, rats, and bees, with no scorching effect on cucumbers; 10% flonicamid suspension showed moderate toxicity, low toxicity, and low risk in zebrafish, rats, and bees, with mild scorching effect on cucumbers; 4% abamectin-acetamiprid microemulsion showed high toxicity, moderate toxicity, and high toxicity in zebrafish, rats, and bees, with mild scorching effect on cucumbers; 24% abamectin-fluoxetine suspension showed highly toxicity, moderate toxicity, and high toxicity in zebrafish, rats, and bees, with moderate scorching effect on cucumbers.

[0044] Table 2 Ecotoxicity Test Results

[0045] Test Example 3 The physicochemical properties of the microemulsions prepared in the embodiments and comparative examples of this invention were tested. The specific test methods are as follows, and the results are shown in Table 3: Active ingredient particle size: The particle size of the active ingredient was determined using a laser nanoparticle size analyzer and a transmission electron microscope.

[0046] Analysis of the wetting performance of spray droplets: Using the static contact angle measurement mode of the DSA100 contact angle meter, cucumber leaves were used as the measurement substrate. The pesticide spray to be tested was injected into the dropper. After the instrument stabilized, the operating software controlled the droplets to fall and recorded the corresponding contact angle.

[0047] Analysis of the anti-evaporation performance of the spray liquid: Take 1.0 μL of spray liquid, drop it vertically onto the cucumber leaf with no initial velocity, start timing when the droplet falls and stop timing when the droplet is completely evaporated, and record the time required for the spray droplet to completely evaporate.

[0048] Microemulsion stability test: The samples of Examples 1-5 and Comparative Examples 1-5 were divided into 3 parts. One part was sealed and stored in a 0℃ constant temperature chamber for 14 days. The other two parts were stored in a -5℃ constant temperature chamber for 7 days and a 54℃ constant temperature chamber for 28 days, respectively. After storage, the samples were taken out, their state was observed, and the stability of the samples at different temperatures was judged.

[0049] Comparative Examples 1-3 were prepared by adding cyclohexanone, fatty acid methyl ester, and methyltetrahydrofuran as solvents, respectively. As shown in Table 3, the evaporation time was longer than that of Examples 1-5, indicating that the microemulsions provided in Examples 1-5 of this invention can effectively improve the anti-evaporation properties of pesticide solutions. The stability of the microemulsions prepared in Comparative Examples 1-3 was significantly worse. Meanwhile, the contact angle of Comparative Example 1 was larger than that of the examples, indicating that the microemulsions of this invention have excellent wetting properties, can quickly wet the leaf surface and effectively penetrate, which greatly helps to improve pesticide efficacy.

[0050] Comparative Example 4, without the addition of decylamide, showed a larger particle size of the active ingredient compared to the Examples, while the active ingredient particles in the Examples were all at the nanometer level. This allows for better penetration into pests through contact and organ penetration, thereby improving efficacy. Furthermore, the PDI of Comparative Example 4 was higher than the average PDI of the Examples, indicating that the addition of decylamide resulted in a more uniform microemulsion particle size distribution.

[0051] Compared to the example, Comparative Example 5 did not contain the synergistic additives silicone and xanthan gum, and its contact angle was larger.

[0052] Table 3. Physicochemical Testing and Performance Evaluation Results

[0053] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0054] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. Furthermore, various different embodiments of the present invention can also be arbitrarily combined, as long as they do not violate the spirit of the present invention, and should also be regarded as the content disclosed by the present invention.

Claims

1. A microemulsion containing abamectin and flonicamid, characterized in that, By weight percentage, it contains the following components: 5-20% flupyradifurone technical grade, 1-10% abamectin technical grade, 15-35% solvent, 1-15% coupling agent, 10-30% emulsifier, 0.1-1% synergist, and deionized water to make up to 100%.

2. The microemulsion containing abamectin and flonicamid according to claim 1, characterized in that, By mass percentage, it contains the following components: 10-15% flupyradifurone technical grade, 1-5% abamectin technical grade, 20-30% solvent, 8-15% coupling agent, 15-25% emulsifier, 0.1-1% synergist, and deionized water to make up to 100%.

3. A microemulsion containing abamectin and flonicamid according to any one of claims 1-2, characterized in that, The solvent is a mixture of fatty acid methyl ester and methyltetrahydrofuran; The coupling agent is decanoic acid; The emulsifier is a composition of tristyrene-phenylphenol polyoxyethylene ether, castor oil polyoxyethylene ether, and calcium dodecylbenzenesulfonate; The synergistic agents are organosilicon compounds and xanthan gum.

4. The microemulsion containing abamectin and flonicamid according to claim 3, characterized in that, The ratio of fatty acid methyl ester to methyltetrahydrofuran is 1-10:1-5 by mass. The ratio of the tristyrene-phenylphenol polyoxyethylene ether, castor oil polyoxyethylene ether, and calcium dodecylbenzenesulfonate is 1-5:1-5:1-5 by mass.

5. A method for preparing a microemulsion containing abamectin and flonicamid according to any one of claims 1-4, characterized in that, Includes the following steps: Add the solvent, coupling agent, and synergist to the preparation vessel and start stirring. Add the flupyradifurone technical and abamectin technical, and stir for 30 minutes to dissolve and mix. Continue to add the emulsifier, stir for 50 minutes to mix evenly, then add the remaining deionized water, shear for 20 minutes, mix evenly, filter after passing the test, and after settling for 12 hours, package to obtain the product.

6. The use of a microemulsion containing abamectin and flonicamid according to any one of claims 1-5 for the control of cucumber aphids.

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