A dispersible oil suspension containing a multi-mycin and an insecticidal ring and a preparation method thereof

Abstract

The present application relates to a dispersible oil suspension containing spinosad and avermectin and a preparation method thereof, the dispersible oil suspension containing spinosad and avermectin is composed of stabilizer, thickening agent, non-water dispersion medium, emulsifier, modified carrier and pesticide mixture; the pesticide mixture is prepared by mixing spinosad and avermectin according to a mass ratio of 1-5:25-35. Compared with the prior art, the dispersible oil suspension containing spinosad and avermectin prepared by the present application has excellent retention, can be released controllably in an alkaline environment, has good storage stability, reduces the loss of pesticides, and has a remarkable effect on killing cucumber thrips.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pesticides, in particular to a thrips-killing composition, and more particularly to a dispersible oil suspension containing spinosad and chlorfenapyr and a preparation method thereof. BACKGROUND

[0002] The main species in cucumber thrips is western flower thrips, which was first discovered in North America and now widely occurs in various parts of the world, and is an important pest that harms agricultural production. In the aspect of agricultural pest control, a pesticide compound composition with synergistic effect can expand the control spectrum, reduce the use dose, and the pests are less likely to develop resistance.

[0003] Pesticide spraying is the most common method for protecting plants from various diseases and pests in modern agriculture. However, the currently available commercial pesticides have serious drawbacks. During spraying, these pesticides exhibit poor retention, which leads to significant loss and waste of the pesticides. The lost pesticides flow into the ground, posing a threat to the ecological environment. Therefore, it is urgent to overcome these drawbacks of the pesticides, improve the utilization rate of the pesticides, and improve the retention rate and stability of the pesticide formulations.

[0004] Invention patent CN113040150A discloses a spinosad dispersible oil suspension for aerial spraying and a preparation method thereof, which belongs to the technical field of pesticides. The spinosad dispersible oil suspension comprises the following components: spinosad 0.5% to 50%, dispersant 0% to 20%, emulsifier 1% to 40%, functional adjuvant 0% to 20%, structure adjusting agent 0% to 10%, and the rest is a dispersing medium. The spinosad dispersible oil suspension of the invention has the advantages of low surface tension, good wetting property, and high retention amount, and the preparation and use method are simple. However, the stability of the dispersible oil suspension is poor, and the field efficacy is low. SUMMARY

[0005] Since the dispersible oil suspension in the prior art has the disadvantages of poor stability, weak persistent insecticidal effect, and low retention rate, the technical problem to be solved by the present application is to provide a dispersible oil suspension containing spinosad and chlorfenapyr, which has good field efficacy, strong stability, and high retention rate.

[0006] To achieve the above-mentioned purpose, the following technical solutions are adopted in the present application:

[0007] A dispersible oil suspension containing spinosad and chlorfenapyr comprises the following components: a stabilizer, a thickening agent, a non-aqueous dispersing medium, an emulsifier, a modified carrier, and a pesticide mixture.

[0008] A dispersible oil suspension agent containing spinosad and insecticidal ring is composed of the following ingredients by weight percentage: 1-3% stabilizer, 0.5-2% thickening agent, 15-25% non-water dispersion medium, 5-10% emulsifier, 30-40% modified carrier, 30-35% pesticide mixture.

[0009] The pesticide mixture is prepared by mixing spinosad and insecticidal ring in a mass ratio of 1-5:25-35.

[0010] The spinosad, also known as spinosad, is a non-pollution high-efficiency biological insecticide extracted from the fermentation liquor of Saccharopolyspora spinosa.

[0011] The insecticidal ring, also known as Yweijia, N,N-dimethyl-1,2,3-trithia-cyclohexane-5-amine and its oxalate, has a molecular weight of 271.26 and a melting point of 125-128 (decomposition).

[0012] A dispersible oil suspension agent containing spinosad and insecticidal ring is prepared by the following method:

[0013] According to the formula, each raw material is weighed, the emulsifier, stabilizer, thickening agent and non-water dispersion medium are mixed, stirred for 1-5h, the stirring speed is 100-500rpm, the mixed liquid A is obtained; the modified carrier and the pesticide mixture are mixed, heated to 35-50℃, stirred for 10-30min, the stirring speed is 200-500rpm, then cooled to room temperature, added to the mixed liquid A, homogenized and dispersed for 1-3h, the homogenization and dispersion speed is 1000-2000rpm, the homogenization and dispersion temperature is 60-80℃, to obtain the dispersible oil suspension agent containing spinosad and insecticidal ring.

[0014] The stabilizer is at least one of isopropyl phosphate, butyl epoxy stearate, soybean lecithin, butyl hydroxy anisole, epoxy chloropropane and tris (nonylphenyl) phosphite.

[0015] The thickening agent is at least one of organic bentonite, sodium alginate, xanthan gum, white carbon black, diatomite, magnesium aluminum silicate.

[0016] The non-water dispersion medium can be at least one of vegetable oil, mineral oil, methyl oleate, butyl oleate, benzenedicarboxylic acid ester.

[0017] The emulsifier is at least one of castor oil polyoxyethylene ether, phenylethyl phenol polyoxyethylene ether, fatty acid ester polyoxyethylene ether, calcium dodecylbenzenesulfonate, fatty alcohol polyoxyethylene ether, sorbitol hexaoleic acid polyoxyethylene ether.

[0018] The preparation method of the modified carrier is as follows, in parts by weight:

[0019] S1, 0.1-1 parts of modified starch is added to 20-40 parts of anhydrous dimethyl sulfoxide, then 0.01-0.1 parts of succinic anhydride is added, stirring at 50-70 °C for 4-8 h, stirring speed is 100-300 rpm, treated with ice water bath for 1-3 h, then centrifuged for 2-10 min, centrifugal speed is 10000-15000 rpm, collect the precipitate, freeze-drying to obtain pre-processed carrier;

[0020] S2, 0.005-0.01 parts of dopamine is added to 0.5-2 parts of 0.1-0.3 wt% NaOH aqueous solution, stirring at room temperature for 0.5-2 h in the dark, stirring speed is 100-500 rpm, to obtain dopamine solution; 0.1-0.2 parts of copper chloride is added to 10-30 parts of water, stirring at room temperature for 4-8 h, stirring speed is 100-300 rpm, to obtain copper chloride aqueous solution; the copper chloride aqueous solution and 0.1-0.3 parts of pre-processed carrier prepared in step S1 is added to the dopamine solution, stirring for 1-3 h, stirring speed is 100-300 rpm, then centrifuged for 1-10 min, centrifugal speed is 8000-12000 rpm, collect the precipitate, washed with water for 1-3 times, freeze-drying to obtain composite carrier;

[0021] S3, 180-220 g of the composite carrier prepared in step S2 and hexadecylamine is added to 1-5 parts of dimethyl sulfoxide, ultrasonic for 5-15 min, ultrasonic power is 200-400 W, ultrasonic frequency is 20-30 kHz, the mass ratio of composite carrier and hexadecylamine is 1:1-5; then heated in a water bath at 50-80 °C for 1-10 min, cooled at room temperature, 10000-14000 rpm centrifuged for 10-30 min to collect the solid, dried at 40-60 °C for 1-3 h, to obtain modified carrier.

[0022] The preparation method of the modified starch is as follows, in parts by weight:

[0023] 5-10 parts of starch is added to 50-80 parts of 0.2-0.5 wt% NaOH aqueous solution, stirring at room temperature for 10-20 min, stirring speed is 100-300 rpm, 5-10 parts of dichloroacetic acid is added, stirring for 1-5 h on a magnetic stirrer, stirring speed is 1000-1500 rpm, to obtain a mixture, adjust to pH 6.8-7.2 with 0.01-0.2 wt% hydrochloric acid, column chromatography with 100-200 parts of dichloromethane ethanol solution, the ratio of dichloromethane to ethanol is 5-15:1, filter through a 300-500 mesh sieve, the collected solid is added to 150-250 parts of methanol and continuously stirred for 0.5-2 h, stirring speed is 100-300 rpm, dried in a vacuum oven at 50-80 °C for 8-15 h, to obtain modified starch.

[0024] The starch is modified by dichloroacetic acid in an alkaline environment, then reacted with succinic anhydride in a solution of anhydrous dimethyl sulfoxide to prepare a pre-processed carrier, then copper chloride and the pre-processed carrier are added to a dopamine solution, freeze-dried to obtain a composite carrier, the composite carrier and hexadecylamine are added to dimethyl sulfoxide, and the modified carrier is obtained by ultrasonic heating reaction; the spinosad and avermectin are coated by the modified carrier, and the dispersible oil suspension containing spinosad and avermectin is obtained by compounding with additives.

[0025] The ester bond is formed between the starch and dichloroacetic acid. The new crystalline region is formed, the diffusion layer is provided, and due to the amphiphilic nature of the modified starch, the modified starch is gelatinized in the aqueous medium, easily forms a complex, and has a tendency of particle aggregation, which is beneficial to the next reaction and the encapsulation of the drug. On the other hand, due to the lamellar structure, the modified starch can accommodate the fillers of the reactants and pesticide molecules. Due to the compatibility, the modified starch can have better interlayer spacing expansion ability when reacting with succinic anhydride. The addition of dopamine improves the stability of the composite carrier. Due to the coordination of copper ions, the composite carrier also has certain alkali-responsive release characteristics. Due to the oxidation of the catechol group of dopamine in an alkaline environment, the copper ion coordination interaction is weakened, and the network structure is depolymerized, thereby showing alkali stimulation response. Since the gastrointestinal tract of insects is mainly alkaline, the release performance of the prepared dispersible oil suspension in an alkaline environment is stronger than that in an acidic or neutral environment, and by utilizing the response characteristics to alkali stimulation, the controlled release of the pesticide in an alkaline environment can be ensured. The retention amount directly affects the utilization of the pesticide, and the retention efficiency of the pesticide carrier can be improved by increasing the adhesion and deposition of the pesticide carrier. Based on dopamine chemistry, the increased leaf retention rate is mainly due to the non-covalent interaction between the catechol functional group of dopamine on the modified carrier and the leaf. This is related to the formation of a network network in the droplet. During the water evaporation process, the dispersible oil suspension of the comparative example 2 is deposited on the leaf in a blurred manner without carrier protection. The dispersible oil suspension is obviously deposited on the leaf surface due to the network skeleton structure formed by the carrier. Since the surface structure of the leaf is mainly composed of hydrophobic waxy components, the network modified carrier formed by the coordination of copper ions has a large contact area with the leaf, and can be closely combined with the leaf structure. In addition, the added dopamine also greatly enhances the leaf adhesion of the dispersible oil suspension loaded with pesticides. Therefore, by chelating copper ions and grafting dopamine, the deposition performance is improved, and the loss of the pesticide is reduced.

[0026] Compared with the prior art, the present application has the following beneficial effects:

[0027] (1) The starch is modified by dichloroacetic acid in an alkaline environment, then reacts with succinic anhydride in a dimethyl sulfoxide solution to prepare a pre-processed carrier, then adds copper chloride and the pre-processed carrier in a dopamine solution, freeze-dries to obtain a composite carrier, adds the composite carrier and hexadecylamine to dimethyl sulfoxide, and obtains a modified carrier through ultrasonic heating reaction; the spinosad and the insecticidal ring are coated by the modified carrier, and the dispersible oil suspension containing the spinosad and the insecticidal ring is obtained by adding additives; the deposition performance is improved, the controlled release can be realized in an alkaline environment, the storage stability is good, and the loss of pesticides is reduced.

[0028] (2) The dispersible oil suspension provided by the application has a significant effect on killing cucumber thrips. DETAILED DESCRIPTION

[0029] In the following, the technical solutions of the application will be described in detail through specific examples, but it should be made clear that these examples are used for illustration, but are not interpreted as limiting the scope of the application.

[0030] The parameters of part of raw materials in the embodiment of the application are as follows:

[0031] Castor oil polyoxyethylene ether, Tianjin Zhonghe Shengtai Chemical Co., Ltd., article number: EL-20, CAS number: 61791-12-6;

[0032] Soybean lecithin, Shandong Chuangtian Biological Technology Co., Ltd., article number: 2017, model number: food grade;

[0033] Organic bentonite, Guangzhou Zhanfei Chemical Technology Co., Ltd., article number: 188B, mesh number: 400 mesh, apparent viscosity: 80 mPa.s;

[0034] Spinosad, Zhejiang Shengtong Biological Technology Co., Ltd., CAS: 131929-60-7;

[0035] Insecticidal ring, Guangzhou Haikang Pharmaceutical Co., Ltd., article number: k88, CAS: 31895-21-3;

[0036] Starch, Langfang Qianyao Technology Co., Ltd., article number: 0145, CAS: 111-22-3;

[0037] Dopamine, Shaanxi Xinkang Biological Technology Co., Ltd., article number: 5616, CAS: 51-61-6;

[0038] Succinic anhydride, Shandong Haoyao New Material Co., Ltd., model number: HY56565, CAS: 108-30-5;

[0039] Hexadecylamine, Wuhan Lanbai White Medicine and Chemical Co., Ltd., product grade: first-class product, item number: DGF3423, CAS: 143-27-1.

[0040] Example 1

[0041] A dispersible oil suspension containing spinosad and avermectin is prepared as follows:

[0042] Mix 7.2 kg of castor oil polyoxyethylene ether, 2 kg of soybean lecithin, 0.8 kg of organic bentonite, and 20 kg of methyl oleate, stir for 3 h at a stirring speed of 300 rpm to obtain a mixed solution A; mix 37 kg of modified carrier and 33 kg of pesticide mixture, heat to 40℃, stir for 20 min at a stirring speed of 300 rpm, then cool to room temperature, add the mixed solution A, homogenize and disperse for 1.5 h at a homogenizing and dispersing speed of 1500 rpm and a homogenizing and dispersing temperature of 70℃ to obtain the dispersible oil suspension containing spinosad and avermectin.

[0043] The preparation method of the modified carrier is as follows:

[0044] S1, add 500 g of modified starch to 30 kg of anhydrous dimethyl sulfoxide, then add 50 g of succinic anhydride, stir at 60℃ for 6 h at a stirring speed of 200 rpm, treat with an ice water bath for 2 h, then centrifuge for 5 min at a centrifugation speed of 12000 rpm, collect the precipitate, and freeze-dry to obtain a pre-processed carrier;

[0045] S2, add 10 g of dopamine to 1 kg of 0.2wt% NaOH aqueous solution, stir at room temperature for 1 h in the dark at a stirring speed of 300 rpm to obtain a dopamine solution; add 125 g of copper chloride to 20 kg of water, continuously stir at room temperature for 6 h at a stirring speed of 200 rpm to obtain a copper chloride aqueous solution; add the copper chloride aqueous solution and 150 g of the pre-processed carrier prepared in step S1 to the dopamine solution, stir for 2 h at a stirring speed of 200 rpm, then centrifuge for 5 min at a centrifugation speed of 10000 rpm, collect the precipitate, wash with water three times, and freeze-dry to obtain a composite carrier;

[0046] S3, add 200 g of the composite carrier prepared in step S2 and hexadecylamine to 3 kg of dimethyl sulfoxide, ultrasonic for 10 min at an ultrasonic power of 300 W and an ultrasonic frequency of 25 kHz, the mass ratio of the composite carrier to hexadecylamine is 1:3; then heat in a water bath at 70℃ for 5 min, cool at room temperature, collect the solid after centrifugation at 12000 rpm for 20 min, and dry at 50℃ for 2 h to obtain the modified carrier.

[0047] The pesticide mixture is prepared by mixing spinosad and avermectin at a mass ratio of 3:30.

[0048] The preparation method of the modified starch is as follows:

[0049] 700 g of starch was added to 6.5 kg of 0.25 wt% NaOH aqueous solution, stirred at room temperature for 18 min at a stirring speed of 200 rpm, 700 g of dichloro-diacetic acid was added, stirred on a magnetic stirrer for 3 h at a stirring speed of 1200 rpm, the mixture was adjusted to pH 7 with 0.1 wt% hydrochloric acid, column chromatography was performed with 15 kg of dichloromethane ethanol solution, the ratio of dichloromethane to ethanol was 10:1, the collected solid was added to 20 kg of methanol and continuously stirred for 1 h at a stirring speed of 200 rpm, and the modified starch was obtained by drying in a vacuum oven at 60°C for 11 h.

[0050] Example 2

[0051] The preparation method of a dispersible oil suspension containing spinosad and avermectin was basically the same as that of Example 1, the only difference being that the preparation method of the modified carrier was different.

[0052] The preparation method of the modified carrier is as follows:

[0053] S1, 500 g of starch was added to 30 kg of anhydrous dimethyl sulfoxide, then 50 g of succinic anhydride was added, stirred at 60°C for 6 h at a stirring speed of 200 rpm, treated with an ice water bath for 2 h, then centrifuged for 5 min at a centrifugal speed of 12000 rpm, the precipitate was collected and freeze-dried to obtain a pre-processed carrier;

[0054] S2, 10 g of dopamine was added to 1 kg of 0.2 wt% NaOH aqueous solution, stirred at room temperature for 1 h in the dark at a stirring speed of 300 rpm to obtain a dopamine solution; 125 g of copper chloride was added to 20 kg of water, continuously stirred at room temperature for 6 h at a stirring speed of 200 rpm to obtain a copper chloride aqueous solution; the copper chloride aqueous solution and 150 g of the pre-processed carrier prepared in step S1 were added to the dopamine solution, stirred for 2 h at a stirring speed of 200 rpm, then centrifuged for 5 min at a centrifugal speed of 10000 rpm, the precipitate was washed with water three times and freeze-dried to obtain a composite carrier;

[0055] S3, 200 g of the composite carrier prepared in step S2 and hexadecylamine were added to 3 kg of dimethyl sulfoxide, ultrasonicated for 10 min at an ultrasonic power of 300 W and an ultrasonic frequency of 25 kHz, the mass ratio of the composite carrier to hexadecylamine being 1:3; then heated in a water bath at 70°C for 5 min, cooled at room temperature, collected the solid after centrifugation at 12000 rpm for 20 min, and dried at 50°C for 2 h to obtain a modified carrier.

[0056] The pesticide mixture is the same as in Example 1.

[0057] Example 3

[0058] A method for preparing a dispersible oil suspension containing spinosad and chlorfenapyr is basically the same as that in Example 1, the only difference is that the preparation method of the modified carrier is inconsistent.

[0059] The preparation method of the modified carrier is as follows:

[0060] S1, 500g of modified starch is added to 30kg of anhydrous dimethyl sulfoxide, then 50g of succinic anhydride is added, stirring at 60℃ for 6h, the stirring speed is 200rpm, and the ice water bath is treated for 2h, then centrifuged for 5min at a speed of 12000rpm, the precipitate is collected, and freeze-dried to obtain a pre-processed carrier;

[0061] S2, 125g of copper chloride is added to 20kg of water, continuously stirring at room temperature for 6h, the stirring speed is 200rpm, to obtain a copper chloride aqueous solution; the copper chloride aqueous solution and 150g of the pre-processed carrier prepared in step S1 are mixed and stirred for 2h, the stirring speed is 200rpm, then centrifuged for 5min at a speed of 10000rpm, the precipitate is washed with water three times, and freeze-dried to obtain a composite carrier;

[0062] S3, 200g of the composite carrier prepared in step S2 and hexadecylamine are added to 3kg of dimethyl sulfoxide, and ultrasonic treatment is performed for 10min, the ultrasonic power is 300W, the ultrasonic frequency is 25kHz, and the mass ratio of the composite carrier to hexadecylamine is 1:3; then heated in a water bath at 70℃ for 5min, cooled at room temperature, centrifuged at 12000rpm for 20min to collect the solid, and dried at 50℃ for 2h to obtain a modified carrier.

[0063] The pesticide mixture is the same as in Example 1.

[0064] The preparation method of the modified starch is the same as in Example 1.

[0065] Example 4

[0066] A method for preparing a dispersible oil suspension containing spinosad and chlorfenapyr is basically the same as that in Example 1, the only difference is that the preparation method of the modified carrier is inconsistent.

[0067] The preparation method of the modified carrier is as follows:

[0068] S1, 500 g of modified starch was added to 30 kg of anhydrous dimethyl sulfoxide, then 50 g of succinic anhydride was added, stirred at 60 °C for 6 h, the stirring speed was 200 rpm, treated with ice water bath for 2 h, then centrifuged for 5 min at a speed of 12000 rpm, the precipitate was collected, freeze-dried to obtain a pre-processed carrier;

[0069] S2, 10 g of dopamine was added to 1 kg of 0.2 wt% NaOH aqueous solution, stirred at room temperature for 1 h in the dark, the stirring speed was 300 rpm, to obtain a dopamine solution; 150 g of the pre-processed carrier prepared in step S1 was added to the dopamine solution, stirred for 2 h, the stirring speed was 200 rpm, then centrifuged for 5 min at a speed of 10000 rpm, the precipitate was collected and washed with water three times, and freeze-dried to obtain a composite carrier;

[0070] S3, 200 g of the composite carrier prepared in step S2 and hexadecylamine were added to 3 kg of dimethyl sulfoxide, and ultrasonic treatment was performed for 10 min, the ultrasonic power was 300 W, the ultrasonic frequency was 25 kHz, and the mass ratio of the composite carrier to hexadecylamine was 1:3; then heated in a water bath at 70 °C for 5 min, cooled at room temperature, centrifuged at 12000 rpm for 20 min to collect the solid, and dried at 50 °C for 2 h to obtain a modified carrier.

[0071] The pesticide mixture is the same as in Example 1.

[0072] The preparation method of the modified starch is the same as in Example 1.

[0073] Comparative Example 1

[0074] A preparation method of a dispersible oil suspension containing spinosad and chlorfenapyr is basically the same as in Example 1, the only difference is that the preparation method of the modified carrier is different.

[0075] The preparation method of the modified carrier is as follows:

[0076] S1, 500 g of modified starch was added to 30 kg of anhydrous dimethyl sulfoxide, then 50 g of succinic anhydride was added, stirred at 60 °C for 6 h, the stirring speed was 200 rpm, treated with ice water bath for 2 h, then centrifuged for 5 min at a speed of 12000 rpm, the precipitate was collected, freeze-dried to obtain a pre-processed carrier;

[0077] S2, 200 g of the pre-processed carrier prepared in step S1 and hexadecylamine were added to 3 kg of dimethyl sulfoxide, and ultrasonic treatment was performed for 10 min at an ultrasonic power of 300 W and an ultrasonic frequency of 25 kHz, and the mass ratio of the pre-processed carrier to hexadecylamine was 1:3; then heating was performed in a water bath at 70 °C for 5 min, and the solid was collected after cooling at room temperature and centrifugation at 12000 rpm for 20 min, and drying was performed at 50 °C for 2 h to obtain a modified carrier.

[0078] The pesticide mixture was the same as in Example 1.

[0079] Comparative Example 2

[0080] A preparation method of a dispersible oil suspension containing spinosad and chlorantraniliprole was basically the same as in Example 1, and the only difference was that no modified carrier was added in the preparation method of the dispersible oil suspension containing spinosad and chlorantraniliprole.

[0081] Test Example 1

[0082] Field efficacy test

[0083] The test site was selected in a cucumber greenhouse in Huanggang, Hubei, which was damaged by cucumber leafworms all year round. Each test treatment was repeated 3 times, and there were a total of 30 plots. A spray volume of 45 ml / mu was used, each example and comparative example was diluted 600 times with water, and a randomized block design was used. Before application, 10 cucumber plants were randomly selected in each plot, and the total number of insect pests on the upper, middle and lower leaves of each cucumber plant was counted. The insect pest base number of 10 cucumber plants in each plot was recorded. On the day of application, a good weather was selected, and a backpack manual sprayer was used to spray wet leaves. The residual insect pest number was investigated 7 and 28 days after application, and the number of insect pests on the front and back of the leaves was observed and recorded under a hand magnifying glass by using a microscope.

[0084] The insect pest reduction rate (%) was calculated according to the following formula:

[0085] Insect pest reduction rate (%) = (insect pest base number before treatment - insect pest number after treatment) / insect pest base number before treatment x 100

[0086] The test results are shown in Table 1.

[0087] Table 1: Field efficacy test results

[0088]

[0089] Test Example 2

[0090] Leaf retention amount determination

[0091] The leaf retention amount of the dispersible oil suspending agent prepared in the application on the surface of cucumber leaves is determined by leaf wetting weighing method according to the test in the doctoral thesis (Construction and adhesion mechanism of leaf-adhesive pesticide drug delivery system, Zhihen, Chinese Academy of Agricultural Sciences, 2020). The dispersible oil suspending agent prepared in the application is diluted 600 times with water, and each treatment is repeated 5 times. Deionized water is used as a control on the crop leaves. First, the leaves are washed with deionized water to reduce experimental error. After the leaves are naturally dried, a puncher with a diameter of 1.5 cm is used to punch out similar-sized cucumber leaf discs. The area S (cm 2 ) of the disc is measured by a leaf area meter. A pair of tweezers is placed in the experimental pesticide solution in the millimeter precision electronic balance (ME-TS), and the data is cleared. The leaves are completely immersed in the pesticide solution for about 20 s, and the time is recorded by a stopwatch. The weight W1 is recorded, and the leaves are taken out. When the pesticide droplets on the leaves are not dripping, the cucumber leaves immersed in the pesticide solution are carefully transferred. The tweezers are placed back in the pesticide solution to be tested, and the weight W2 is recorded. The retention amount of the pesticide solution on the cucumber leaves in each experimental group is calculated according to the following formula:

[0092] R (mg / cm 2 ) = (W1-W2) / S

[0093] The test results are shown in Table 2.

[0094] Table 2: Leaf retention amount determination results

[0095]

[0096]

[0097] Test Example 3

[0098] Storage stability test

[0099] According to the national pesticide stability standards, GB / T19137-2003 "Pesticide Low Temperature Stability Determination Method", NY / T1427-2016 "Pesticide Normal Temperature Storage Stability Test General", GB / T19136-2003 "Pesticide Hot Storage Stability Determination Method", the storage stability of the dispersible oil suspension agent in different environments is evaluated and analyzed. The same content of dispersible oil suspension agent 3 is weighed in a quartz test tube with a tube plug, and is stored in a constant temperature box at 4℃, 25℃ and 54℃, respectively. The 4℃ treatment group is stored for 7 days, and the particle size of the sample is measured by Malvern laser particle size analyzer at 7d; the 25℃ and 54℃ treatment groups are stored for 14 days, and the particle size of the sample is measured by Malvern laser particle size analyzer; finally, the sample of each treatment group is transferred to a 50mL capacity bottle, and is dissolved with methanol to the mark line, and is detected by machine after passing through an organic microporous membrane. The test results are shown in Table 3.

[0100] Table 3: Storage stability test results

[0101]

[0102]

[0103] From the test results of test examples 1-3, it can be seen that the dispersible oil suspension agent containing spinosad and chlordecone prepared by the present application has good field efficacy, high leaf retention and good storage stability. The main reason is that the starch is modified by dichloroacetic acid in an alkaline environment, and then reacted with succinic anhydride in a dimethyl sulfoxide solution to prepare a pre-processed carrier, then copper chloride and the pre-processed carrier are added to the dopamine solution, freeze-dried to obtain a composite carrier, the composite carrier and hexadecylamine are added to dimethyl sulfoxide, and the modified carrier is obtained by ultrasonic heating reaction; spinosad and chlordecone are coated by the modified carrier, and the dispersible oil suspension agent containing spinosad and chlordecone is obtained by adding additives.

[0104] The ester bond is formed between starch and dichloroacetic acid. The new crystalline region is formed, the diffusion layer is provided, and due to the amphiphilic nature of the modified starch, the modified starch is gelatinized in the water medium, easy to form a complex, and there is a tendency of particle aggregation, which is beneficial to the next step of the reaction and the encapsulation of the drug. On the other hand, the modified starch can accommodate the reactants and pesticide molecules due to the lamellar structure. Due to the compatibility, the modified starch can have better interlayer spacing expansion ability when reacting with succinic anhydride. Then the addition of dopamine improves the stability of the composite carrier. Due to the coordination of copper ions, the composite carrier also has certain alkali-responsive release characteristics. Due to the oxidation of the catechol group of dopamine in the alkaline environment, the copper ion coordination interaction is weakened, and the network structure is depolymerized, thereby showing the alkali stimulus response. Since the gastrointestinal tract of insects is mainly alkaline, the release performance of the prepared dispersible oil suspension agent in the alkaline environment is better than that in the acidic or neutral environment, and by utilizing this alkali stimulus response characteristic, the controlled release of the pesticide in the alkaline environment can be ensured. The retention amount directly affects the utilization of the pesticide, and the retention efficiency of the pesticide carrier can be improved by increasing the adhesion and deposition of the pesticide carrier. Based on dopamine chemistry, the increased leaf retention is mainly due to the non-covalent interaction between the catechol functional group of dopamine on the modified carrier and the leaf. This is related to the network network easily formed in the droplet. During the water evaporation process, the dispersible oil suspension agent of the comparative example 2 is deposited on the leaf in a blurred manner due to the lack of carrier protection. The dispersible oil suspension agent will be obviously deposited on the leaf surface due to the network skeleton structure formed by the carrier. Since the leaf surface structure is mainly composed of hydrophobic wax components, the network modified carrier formed by the coordination of copper ions has a large contact area with the leaf, and the leaf structure is tightly combined. In addition, the added dopamine also greatly enhances the leaf adhesion of the dispersible oil suspension agent loaded with the pesticide. Therefore, by chelating copper ions and grafting dopamine, the deposition performance is improved, and the loss of the pesticide is reduced.

Claims

1. A dispersible oil suspension containing spinosad and fenamiphos, characterized in that, The composition is made of the following ingredients: 1-3% stabilizer, 0.5-2% thickening agent, 15-25% non-water dispersion medium, 5-10% emulsifier, 30-40% modified carrier, and 30-35% pesticide mixture. The preparation method of the modified carrier is as follows, in terms of weight parts: S1, 0.1-1 parts of modified starch is added into 20-40 parts of anhydrous dimethyl sulfoxide, then 0.01-0.1 parts of succinic anhydride is added, stirring at 50-70℃ for 4-8h, stirring speed is 100-300rpm, ice water bath treatment for 1-3h, then centrifugation for 2-10min, centrifugal speed is 10000-15000rpm, collect the precipitate, freeze-drying to obtain pre-processing carrier; S2, 0.005-0.01 parts of dopamine is added into 0.5-2 parts of 0.1-0.3wt% NaOH aqueous solution, stirring at room temperature for 0.5-2h in the dark, stirring speed is 100-500rpm, to obtain dopamine solution; 0.1-0.2 parts of copper chloride is added into 10-30 parts of water, stirring at room temperature for 4-8h, stirring speed is 100-300rpm, to obtain copper chloride aqueous solution; the copper chloride aqueous solution and 0.1-0.3 parts of pre-processing carrier prepared in step S1 is added into the dopamine solution, stirring for 1-3h, stirring speed is 100-300rpm, then centrifugation for 1-10min, centrifugal speed is 8000-12000rpm, collect the precipitate, washing with water for 1-3 times, freeze-drying to obtain composite carrier; S3, 180-220g of the composite carrier prepared in step S2 and hexadecylamine is added into 1-5 parts of dimethyl sulfoxide, ultrasonic for 5-15min, ultrasonic power is 200-400W, ultrasonic frequency is 20-30kHz, the mass ratio of composite carrier and hexadecylamine is 1:1-5; then heated in a water bath at 50-80℃ for 1-10min, cooled at room temperature, centrifugation for 10-30min at 10000-14000rpm to collect the solid, dried at 40-60℃ for 1-3h to obtain the modified carrier; The preparation method of the modified starch is as follows, in terms of weight parts: 5-10 parts of starch is added into 50-80 parts of 0.2-0.5wt% NaOH aqueous solution, stirring at room temperature for 10-20min, stirring speed is 100-300rpm, 5-10 parts of dichloroacetic acid is added, stirring for 1-5h on a magnetic stirrer, stirring speed is 1000-1500rpm, to obtain a mixture, adjust to pH 6.8-7.2 with 0.01-0.2wt% hydrochloric acid, column chromatography with 100-200 parts of dichloromethane ethanol solution, the ratio of dichloromethane to ethanol is 5-15:1, filter through a 300-500 mesh sieve, collect the solid and continuously stir in 150-250 parts of methanol for 0.5-2h, stirring speed is 100-300rpm, dry in a vacuum oven at 50-80℃ for 8-15h to obtain the modified starch.

2. The dispersible oil suspension containing polyoxin and chinomethionat according to claim 1, characterized in that, The pesticide mixture is prepared by mixing spinosad and thiocyclam in a mass ratio of 1-5:25-35.

3. A process for the preparation of a dispersible oil suspension concentrate comprising a plurality of the spores of Bacillus thuringiensis and a plurality of the spores of Bacillus popilliae according to any one of claims 1 to 2, characterized in that, The preparation steps are as follows: According to the formula, each raw material is weighed, the emulsifier, stabilizer, thickening agent and non-aqueous dispersion medium are mixed, stirred for 1-5 h, the stirring speed is 100-500 rpm, a mixed solution A is obtained; the modified carrier and the pesticide mixture are mixed, heated to 35-50 DEG C, stirred for 10-30 min, the stirring speed is 200-500 rpm, then cooled to room temperature, added into the mixed solution A, homogenously dispersed for 1-3 h, the homogenously dispersion speed is 1000-2000 rpm, the homogenously dispersion temperature is 60-80 DEG C, a dispersible oil suspension containing spinosad and thiocyclam is obtained.

4. The method of claim 3, wherein, The stabilizer is at least one of isopropyl phosphate, butyl epoxy stearate, soybean lecithin, butylated hydroxyanisole, epichlorohydrin and trisnonylphenyl phosphite.

5. The method of claim 3, wherein, The thickening agent is at least one of organic bentonite, sodium alginate, xanthan gum, white carbon black, diatomite, magnesium aluminum silicate.

6. The method of claim 3, wherein, The non-aqueous dispersion medium is at least one of vegetable oil, mineral oil, methyl oleate, butyl oleate, phthalate ester.

7. The method of claim 3, wherein, The emulsifier is at least one of castor oil polyoxyethylene ether, phenylethyl phenol polyoxyethylene ether, fatty acid ester polyoxyethylene ether, calcium dodecyl benzene sulfonate, fatty alcohol polyoxyethylene ether, sorbitol hexaoleic acid ester polyoxyethylene ether.

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