A miticide and its use

Abstract

The application belongs to the technical field of pesticide acaricidal technology, and discloses an acaricide and application thereof. The acaricide comprises active ingredient A and active ingredient B. The active ingredient A is a compound of formula I. The active ingredient B is any one of flujaepram or bromopropylate. The mass ratio of the active ingredient A to the active ingredient B is 1:45-42:1. The acaricide has obvious synergistic effect on various harmful mites, can effectively control the harm of the harmful mites, and reduces the use amount of the pesticide and slows down the development of the resistance of the harmful mites.

Description

Technical Field

[0001] This invention belongs to the field of pesticide acaricide technology, and discloses an acaricide and its application. Background Technology

[0002] Pyrimethanil is a class of methamidoacrylate acaricides, CAS number 229977-93-9. Its mechanism of action involves inhibiting mitochondrial respiration through electron transfer between cytochrome b and cytochrome c1. Pyrimethanil can be used to control various mites on fruit trees, such as apple spider mites and citrus spider mites. Its structural formula is shown below:

[0003]

[0004] Bromoxyfen is a low-toxicity, broad-spectrum acaricide with strong contact action, no systemic activity, and a long residual effect. It has a certain killing effect on adult mites, nymphs, and eggs. Its structural formula is shown below:

[0005]

[0006] Currently, the control of spider mites on fruit trees employs a combination of agricultural, chemical, and biological methods. However, due to the small size and high concealment of spider mites, they are often difficult to detect in their early stages, leading to missed opportunities for optimal control. Therefore, when mite infestations are severe or the population is large, chemical pesticides remain the primary means of control. However, the prolonged, excessive, and singular use of chemical pesticides has resulted in a very serious problem of pesticide resistance in fruit tree spider mites. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides an acaricide that has a significant synergistic effect on spider mites, effectively slowing down the accumulation of resistance in mites, reducing pesticide costs, and minimizing environmental pollution.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: an acaricide, wherein the acaricide comprises active ingredient A and active ingredient B, wherein active ingredient A is a compound of formula I: The active ingredient B is either pyrimethanil or bromopropylate;

[0009] Furthermore, the mass ratio of active ingredient A to active ingredient B is 1:45 to 42:1;

[0010] Furthermore, the active ingredient B is pyrimethanil, and the mass ratio of active ingredient A to active ingredient B is 1:38 to 32:1;

[0011] The active ingredient B is bromopropylate, and the mass ratio of active ingredient A to active ingredient B is 1:36 to 42:1.

[0012] Furthermore, the active ingredient B is pyrimethanil, and the mass ratio of active ingredient A to active ingredient B is 1:25 to 30:1;

[0013] The active ingredient B is bromopropylate, and the mass ratio of active ingredient A to active ingredient B is 1:32 to 42:1;

[0014] Furthermore, the total weight of the acaricide is 100 wt%, and the total weight of active ingredient A and active ingredient B accounts for 1 wt% to 80 wt% of the total weight of the acaricide.

[0015] Furthermore, in addition to the active ingredient, the acaricide also includes auxiliary ingredients, which are selected from one or more of the following: wetting agents, dispersants, emulsifiers, thickeners, disintegrants, antifreeze agents, defoamers, solvents, preservatives, stabilizers, synergists, or carriers.

[0016] Furthermore, the acaricide can be prepared into a solid dosage form and / or a liquid dosage form;

[0017] Furthermore, the solid formulation is a water-dispersible granule, and the liquid formulation is a suspension concentrate, emulsifiable concentrate, suspension emulsion, or dispersible oil suspension.

[0018] The present invention also discloses the use of the acaricide described above for the prevention and control of harmful mites.

[0019] Furthermore, the pests are spider mites, specifically apple spider mites and / or citrus spider mites.

[0020] The beneficial effects of this invention are as follows:

[0021] 1. The acaricide of the present invention has excellent control effect on mites on fruit tree leaves, can effectively slow down the accumulation of resistance in mites, and has a significant control effect on mites that have developed resistance.

[0022] 2. The acaricide of the present invention reduces the amount of pesticides used, reduces the cost of pesticide application, and reduces environmental pollution. Detailed Implementation

[0023] To make the technical solutions, objectives and advantages of the present invention clearer, the present invention is described with the following preparation examples and specific embodiments. However, the present invention can be implemented in various forms and should not be limited to the embodiments described herein.

[0024] Formulation preparation example:

[0025] Preparation Example 1: 36% Compound I·Pyrimethanil Emulsifiable Concentrate (1:5)

[0026] Formula composition: 6% Formula I compound, 30% pyrimethanil, 12% DMF, 10% styrene-phenol polyoxyethylene ether, 2% calcium dodecylbenzenesulfonate, 20% dichloromethane, xylene to make up the balance.

[0027] Preparation method: The measured active ingredients, solvent, and co-solvent are added to a mixing tank and stirred to dissolve them. Then, the emulsifier is added, and the remaining solvent is used to make up the balance. The mixture is stirred evenly in a mixing tank and filtered to obtain the emulsifiable oil required by this invention.

[0028] Preparation Example 2: 27% Formula I compound·pyrimethanil suspension (8:1)

[0029] Formula composition: 24% Formula I compound, 3% pyrimethanil, 2% EO / PO block polyether, 1% naphthalene sulfonate formaldehyde condensate, 2% styrene phenol polyoxyethylene ether phosphate, 0.2% xanthan gum, 1% magnesium aluminum silicate, 0.5% silicone oil, 5% ethylene glycol, 0.01% potassium benzisothiazolinone, deionized water to make up the balance.

[0030] Preparation method: According to the formula ratio, the active ingredients, surfactants and other functional additives are placed in the reaction vessel in sequence, water is added and mixed evenly, and then subjected to high-speed shearing, wet sand milling and finally homogenization filtration to obtain the suspension product.

[0031] Preparation Example 3: 25% Compound I·Pyrimethanil Suspension Emulsion (2:3)

[0032] Formula composition: 10% Formula I compound, 15% pyrimethanil, 15% solvent oil 150#, 4% Agrilan 788, 2% EO / PO block polyether, 3% fatty alcohol polyoxyethylene ether phosphate, 1% fatty alcohol polyoxyethylene ether sulfate, 5% ethylene glycol, 0.3% xanthan gum, 0.5% silicone defoamer, 0.8% magnesium aluminum silicate, 0.01% sodium benzoate, deionized water to make up the balance.

[0033] Preparation method: According to the formula ratio, the compound of formula I is completely dissolved in a solvent to prepare an oil phase; the active ingredient A, wetting and dispersing agent, antifreeze, defoamer, deionized water, etc. are wet-milled until D90 is less than 5μm to prepare a suspension mother liquor; the oil phase is added to the suspension mother liquor and stirred evenly, and then a thickener is added and stirred and sheared evenly to prepare the suspension emulsion formulation of the composition of the present invention.

[0034] Preparation Example 4: 15% Formula I compound·pyrimethanil dispersible oil suspension (2:1)

[0035] Formula composition: 10% Formula I compound, 5% pyrimethanil, 1% lignin sulfonate, 12% alkyl aryl polyoxyethylene polyoxypropylene ether, 3% fatty alcohol polyoxyethylene ether, 2% calcium dodecylbenzene sulfonate, 0.5% silica, 0.5% organic bentonite, soybean oil to make up the balance;

[0036] Preparation method: According to the formula ratio, the active ingredients, surfactants and other functional additives are placed in the reaction vessel in sequence, oil is added and mixed evenly, and then subjected to high-speed shearing, wet sand milling and finally homogenization filtration to obtain the dispersible oil suspension product.

[0037] Preparation Example 5: 32% Formula I compound·pyrimethanil water-dispersible granules (7:1)

[0038] Formula composition: 28% Formula I compound, 4% pyrimethanil, 8% sodium lignosulfonate, 2.5% BX splitting powder, 8% naphthalene sulfonate formaldehyde condensate, 5% ammonium sulfate, and kaolin to make up the balance.

[0039] Preparation method: According to the formula ratio, add the active ingredients to the carrier, and add surfactants and other functional additives to it. Mix, and after air jet milling, add 10-25% water. Then knead, granulate, dry and sieve to obtain water-dispersible granules; or spray water, granulate and dry the pulverized powder in a fluidized bed granulator, and then sieve to obtain the product.

[0040] Preparation Example 6: 36% Formula I compound bromopropylate emulsifiable concentrate (1:8)

[0041] Formula composition: 4% Formula I compound, 32% bromopropylate, 15% N-methylpyrrolidone, 12% alkylphenol polyoxyethylene ether, 2% calcium dodecylbenzenesulfonate, 8% DMF, xylene to make up the balance.

[0042] Preparation method: Same as in preparation example 1.

[0043] Preparation Example 7: 21% Formula I compound·bromopropylate suspension emulsion (1:2)

[0044] Formula composition: 7% Formula I compound, 14% bromopropylate, 3% EO / PO block polyether, 1% calcium dodecylbenzenesulfonate, 1% fatty alcohol polyoxyethylene ether, 3% styrene-phenol polyoxyethylene ether phosphate, 1% polycarboxylate, 5% propylene glycol, 0.3% xanthan gum, 0.5% silicone defoamer, 0.5% magnesium aluminum silicate, 0.5% Kathon, deionized water to make up the balance.

[0045] Preparation method: According to the formula ratio, heat and melt the compound of formula I, add emulsifier, stir evenly, add water to form an aqueous emulsion phase; wet-mill the active ingredient B with wetting and dispersing agent, antifreeze agent, defoamer, deionized water, etc. until D90 is less than 5μm to form a suspension mother liquor; add the aqueous emulsion phase to the suspension mother liquor and stir evenly, add thickener and stir and shear evenly to prepare the suspension emulsion formulation of the composition of the present invention.

[0046] Preparation Example 8: 25% Formula I compound·bromopropylate suspension (4:1)

[0047] Formula composition: 20% Formula I compound, 5% bromopropylate, 1% fatty alcohol polyoxyethylene ether, 1% sodium alkyl sulfonate, 3% styrene-phenol polyoxyethylene ether sulfate, 2% alkyl aryl polyoxyethylene ether polyoxypropylene ether, 0.5% magnesium aluminum silicate, 0.2% xanthan gum, 4% propylene glycol, 0.2% potassium benzoate, 0.5% silicone oil, deionized water to make up the balance;

[0048] Preparation method: Same as in preparation example 3.

[0049] Preparation Example 9: 22% % Formula I compound bromopropylate dispersible oil suspension (10:1)

[0050] Formula composition: 20% Formula I compound, 2% bromopropylate, 1% alkylphenol polyoxyethylene ether, 12% polyoxyethylene dehydrated sorbitan monooleate, 2% calcium dodecylbenzene sulfonate, 1% succinate sulfonate, 1% Tesco 869, corn oil to make up the balance;

[0051] Preparation method: Same as in preparation example 4.

[0052] Preparation Example 10: 40% Formula I compound bromopropylate water-dispersible granules (1:1)

[0053] Formula composition: 20% Formula I compound, 20% bromopropylate, 10% lignin sulfonate, 2% sodium dodecyl sulfate, 8% sodium polycarboxylate, 5% silica, 30% starch, and kaolin to make up the balance.

[0054] Preparation method: Same as in preparation example 5.

[0055] All the preparations prepared in the above examples have been tested and found to meet the quality and technical indicators required for the corresponding preparations. The preparations obtained are qualified preparations recognized in this field.

[0056] Example 1: Indoor bioactivity test of compound acaricide against citrus red spider mite and two-spotted spider mite

[0057] Test basis: The test was conducted in accordance with NY / T 1154.12-2008 "Guidelines for the determination of biological activity of pesticides in the laboratory - Insecticides - Part 12: Tetranychus slide immersion method".

[0058] Experimental targets: adult female Panonychus citri and Tetranychus urticae Koch.

[0059] Experimental Method: Select female adult mites in the same physiological state. Cut 2cm lengths of double-sided tape and attach it to one end of a glass slide. Select healthy female adult mites and attach them to the double-sided tape, 30 mites per slide. After treatment, place the mites in a container lined with a damp sponge, cover, and place at (25±1)℃. After 2 hours, examine under a microscope, remove dead, injured, and inactive individuals, and replenish to 30 mites per slide.

[0060] Drug preparation: Dissolve the technical grade compound I, pyrimethanil, and bromomethanil in a suitable solvent and prepare a stock solution. Then, prepare five series of mass concentration gradients by mixing them with 0.1% Tween-80 aqueous solution in equal proportions.

[0061] Experimental method: Immerse the glass slide in the above reagent and gently shake for 5 seconds. Remove the slide, absorb the excess reagent with absorbent paper, place it in a white porcelain dish with a damp sponge, and cover it with a transparent plastic film. Repeat each treatment 4 times, and set up a blank control with no reagent (containing all organic solvents and emulsifiers).

[0062] Feeding and observation: The treated mites were fed and observed at (25±1)℃ with a photoperiod L:D=(16:8)h. After 48 hours of treatment, the mites were checked for mortality, and the total number of mites and the number of dead mites were recorded.

[0063] Data statistics and analysis:

[0064] Based on the survey data, the corrected mortality rates for each treatment were calculated using the following formula.

[0065]

[0066] In the formula:

[0067] P – Mortality rate, expressed as a percentage (%);

[0068] K represents the number of dead insects, in heads;

[0069] N represents the total number of insects treated, in units of heads.

[0070]

[0071] In the formula:

[0072] P1 – Corrected mortality rate, in percentage (%);

[0073] Pt —The mortality rate is expressed as a percentage (%).

[0074] P0 – Mortality rate in the blank control group, expressed as a percentage (%).

[0075] If the control mortality rate is <5%, no correction is needed; if the control mortality rate is between 5% and 20%, correction should be performed according to the corrected mortality rate formula; if the control mortality rate is >20%, the trial needs to be repeated.

[0076] The LC was determined using the DPS statistical analysis system. 50 The value is used to evaluate the activity of the test reagent on the biological sample.

[0077] The co-toxicity coefficient (CTC value) of the mixture is calculated using the following formula:

[0078]

[0079] In the formula:

[0080] ATI – Actual Measured Toxicity Index of Mixtures;

[0081] S – LC50 of standard acaricides 50 The unit is milligrams per liter (mg / L);

[0082] M – LC of the mixture 50 The unit is milligrams per liter (mg / L).

[0083] TTI = TI A ×P A +TI B ×P B

[0084] In the formula:

[0085] TTI – Theoretical Toxicity Index of Mixtures;

[0086] TI A —A. Toxicity index of drug A;

[0087] P A —Percentage content of drug A in the mixture, expressed as percentage (%);

[0088] TI B —Toxicity index of drug B;

[0089] P B —Percentage content of agent B in the mixture, expressed as percentage (%).

[0090]

[0091] In the formula:

[0092] CTC – Cotoxicity Coefficient;

[0093] ATI – Actual Measured Toxicity Index of Mixtures;

[0094] TTI – Theoretical Toxicity Index of Mixtures.

[0095] The co-toxicity coefficient of the compound is ≥120, which shows a synergistic effect; CTC≤80 shows an antagonistic effect; and 80<CTC<120 shows an additive effect.

[0096] The indoor activity test results are shown in the table below:

[0097] Table 1. Results of indoor bioactivity tests of compound I and pyrimethanil on *Pseudomonas citrus*.

[0098] Test reagents <![CDATA[LC 50 (mg / L)]]> ATI TTI Cotoxicity coefficient (CTC) Compound (A) of Formula I 3.0869 63.079 / / Pyrimethanil (B) 1.9472 100.000 / / A:B = 1:38 1.6949 114.886 99.053 115.984 A:B = 1:25 1.5068 129.228 98.580 131.089 A:B = 1:16 1.2833 151.734 97.828 155.102 A:B = 1:8 1.2198 159.633 95.898 166.461 A:B = 1:4 1.0976 177.405 92.616 191.549 A:B = 3:2 1.2146 160.316 72.310 205.936 A:B = 8:1 1.5604 124.789 67.182 185.748 A:B = 15:1 1.7132 113.659 65.387 173.825 A:B = 22:1 1.7850 109.087 64.685 168.644 A:B = 30:1 2.2072 88.220 64.270 137.264 A:B = 35:1 2.4280 80.198 64.105 125.104

[0099] The results of the indoor tests in Table 1 show that compound I and pyrimethanil are effective against *Pseudomonas citrinum* when combined. The mass ratio of the two compounds is 1:25 to 35:1. The co-toxicity coefficient against *Pseudomonas citrinum* is greater than 120, indicating a significant synergistic effect.

[0100] Table 2 shows the results of indoor bioactivity tests of compound I combined with bromopropylate on *Pseudomonas citrus*.

[0101]

[0102]

[0103] The results of the indoor tests in Table 2 show that compound I and bromopropylate are effective against *Pseudomonas citrinum* in a mass ratio of 1:32 to 45:1. The co-toxicity coefficient against *Pseudomonas citrinum* is greater than 120, indicating a significant synergistic effect.

[0104] Table 3. Results of indoor bioactivity tests of compound I combined with pyrimethanil on Tetranychus davidii.

[0105] Test reagents <![CDATA[LC 50 (mg / L)]]> ATI TTI Cotoxicity coefficient (CTC) Compound (A) of Formula I 4.8449 70.047 / / Pyrimethanil (B) 3.3937 100.000 / / A:B = 1:38 2.7286 124.375 99.232 125.338 A:B = 1:24 2.3245 145.997 98.802 147.767 A:B = 1:12 2.2995 147.584 97.696 151.065 A:B = 1:8 2.0482 165.692 96.672 171.396 A:B = 2:3 2.0636 164.455 88.019 186.841 A:B = 2:1 2.3475 144.567 80.031 180.638 A:B = 7:1 2.8199 120.348 73.791 163.093 A:B = 14:1 3.2826 103.385 72.044 143.502 A:B = 28:1 3.4645 97.956 71.080 137.812 A:B = 32:1 3.8656 87.792 70.955 123.730 A:B = 44:1 4.3959 77.201 70.712 109.177

[0106] The results of the indoor tests in Table 3 show that the compound of Formula I combined with pyrimethanil has excellent acaricidal activity. The mass ratio of the two is 1:38 to 32:1, and the co-toxicity coefficient against two-spotted spider mites is greater than 120, indicating a significant synergistic effect.

[0107] Table 4. Results of indoor bioactivity tests of compound I combined with bromopropylate on Tetranychus davidii.

[0108]

[0109]

[0110] The results of the indoor tests in Table 4 show that the compound of Formula I combined with bromopropylate has excellent acaricidal activity. The mass ratio of the two is 1:36 to 42:1, and the co-toxicity coefficient against two-spotted spider mites is greater than 120, indicating a significant synergistic effect.

[0111] Example 2: Field efficacy trial for controlling citrus spider mites

[0112] Experimental Location: The experiment was conducted in a citrus orchard at Wusi Farm, Yanxi Town, Changtai County, Fujian Province. The citrus trees in the experimental area were vigorous, and the soil was red soil with moderate fertility. Cultivation conditions were consistent throughout the experimental area. No other pesticides were used to control non-target organisms during the entire experimental period.

[0113] Experimental target: Citrus spider mite.

[0114] Experimental crop: Citrus (Lugan), 10-year-old trees.

[0115] Test reagents: See Table 5 for test reagents, control reagents and dosages.

[0116] Experimental setup: The experiment was conducted with 6 treatments based on the experimental agent, 2 citrus trees in each experimental plot, 4 replicates of each treatment, and all experimental plots were arranged in a randomized block design.

[0117] Experimental Methods: In mid-to-late June 2019, pesticides were applied according to the experimental design at the early stage of citrus red spider mite infestation. During application, the pesticides for each treatment were evenly sprayed onto both sides of the crop leaves using a Gongnong-16 backpack manual sprayer. The entire experiment was conducted with one application.

[0118] Investigation time and frequency: A baseline survey was conducted before pesticide application, and the number of surviving mites was investigated 7 days and 15 days after pesticide application. Two fruit trees were investigated for each treatment. Two leaves with citrus red spider mites were randomly selected from the upper, middle and lower parts of each tree, divided into five directions: east, west, south, north and center. That is, 10 leaves were investigated for each fruit tree and 20 leaves were investigated for each plot. Observation was carried out using a handheld magnifying glass.

[0119] Crop safety survey: No adverse effects of any of the pesticide treatments on citrus were found during the trial.

[0120] Methods for calculating drug efficacy:

[0121]

[0122]

[0123] Experimental Results and Analysis:

[0124] Table 5 Results of field efficacy trials for controlling citrus spider mites

[0125]

[0126] Field efficacy results for controlling citrus red spider mites showed that combining Formula I compound with either pyrimethanil or bromopropylate exhibited good control effects against the citrus red spider mite. Field efficacy results indicated that 27% Formula I compound·pyrimethanil suspension (8:1) and 22% Formula I compound·bromopropylate oil dispersible suspension (10:1) achieved control efficacies of 95.55% and 93.58% respectively 15 days after application.

[0127] Example 2: Field efficacy trial for controlling apple spider mites

[0128] Experimental Location: The experiment was conducted in an apple orchard in Wujia Village, Shilihe Town, Jinan City, Shandong Province. The apple trees in the experimental area were of similar growth age and 8 years old. The orchard management level was average, and the cultivation, water and fertilizer management conditions were consistent across all experimental plots.

[0129] Experimental target: The experimental site was a mixed population of two-spotted spider mites and apple spider mites, with two-spotted spider mites being the dominant species.

[0130] Experimental crop: Apple tree (Fuji).

[0131] Test reagents: See Table 6 for test reagents, control reagents and dosages.

[0132] Experimental setup: The experiment consisted of 6 treatments, each of which was repeated 4 times. Each replicate consisted of 2 apple trees, and all experimental plots were arranged in a randomized block design.

[0133] Experimental method: The experiment was conducted at the early stage of apple red spider mite infestation. The Weishi brand WS-18D backpack electric sprayer was used to apply the pesticide evenly to the entire fruit tree. The amount of pesticide applied was such that the pesticide was evenly applied to both sides of the leaves and a few drops fell off.

[0134] No other pesticides were sprayed during the trial, and the same fungicides and insecticides were applied to all test plots at other times.

[0135] Investigation time and number of investigations: The base number of mites was investigated before the application of pesticides, and the investigation was carried out 4 days and 10 days after the application of pesticides. Two apple trees were investigated in each plot. Short branches were fixed in five directions (east, west, south, north, and center) of each fruit tree. A magnifying glass was used to conduct a fixed-point investigation and record the number of active mites on the front and back of the five leaves at the end of the fixed branches.

[0136] Effects on crops and other organisms: No phytotoxicity was observed in any of the treatments during the field trials, indicating that the prepared samples were safe for apple trees at the supplied reagent amounts.

[0137] Methods for calculating drug efficacy:

[0138]

[0139]

[0140] Experimental Results and Analysis:

[0141] Table 6 Results of field efficacy trials for controlling apple spider mites

[0142]

[0143] Field efficacy trials showed that the acaricide composition of the present invention also has a certain control effect on apple red spider mites, and has good rapid effect and long-lasting effect, which can effectively control the damage of mites to fruit trees.

[0144] Although the present invention has been described in detail above with general description and specific embodiments, some modifications or improvements can be made to it based on the present invention, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention are within the scope of protection claimed by the present invention.

Claims

1. An acaricide, characterized in that, The acaricide comprises active ingredient A and active ingredient B, wherein active ingredient A is a compound of formula I: (Formula I), wherein the active ingredient B is pyrimethanil, and the mass ratio of active ingredient A to active ingredient B is 1:38~32:

1.

2. The acaricide according to claim 1, characterized in that, The mass ratio of active ingredient A to active ingredient B is 1:25 to 30:

1.

3. The acaricide according to claim 1, characterized in that, The total weight of the acaricide is 100 wt%, and the total weight of active ingredient A and active ingredient B accounts for 1 wt% to 80 wt% of the total weight of the acaricide.

4. The acaricide according to claim 1, characterized in that, In addition to the active ingredient, the acaricide also includes auxiliary ingredients, which are selected from one or more of the following: wetting agents, dispersants, emulsifiers, thickeners, disintegrants, antifreeze agents, defoamers, solvents, preservatives, stabilizers, synergists, or carriers.

5. The acaricide according to claim 1, characterized in that, The acaricide is prepared into a solid dosage form and / or a liquid dosage form.

6. The acaricide according to claim 5, characterized in that, The solid formulation is a water-dispersible granule, and the liquid formulation is a suspension, emulsifiable concentrate, suspension emulsion, or dispersible oil suspension.

7. The use of the acaricide according to any one of claims 1-6 for the control of harmful mites, characterized in that, The mites mentioned are the Citrus Paronychia and the Two-spotted Tetranychus.

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