A caricide and its preparation method and application

Abstract

The invention discloses an acaricide, a preparation method and an application thereof, and belongs to the technical field of pesticides. The active ingredients of the acaricide are spirodiclofen and scoparia lactone. The synergistic effect of scoparia lactone and spirodiclofen can effectively increase the mite control effect, and solve the problem that mites easily develop resistance to spirodiclofen. The acaricide is in the form of a viscous liquid and can firmly adhere to the surface of plants after spraying, thus solving the problem that the acaricide has poor adhesion to the plant surface, resulting in the loss of active ingredients and reduced acaricidal effect. At the same time, the acaricide can adhere to the surface of mites, and the mites attached to the acaricide can carry the acaricide to the mite colony to poison other mites, thereby further improving the mite control effect.

Description

Technical Field

[0001] The present invention relates to the technical field of pesticides, and in particular to an acaricide and a preparation method and application thereof. Background Art

[0002] Agricultural pests, due to their high reproductive capacity, short generation cycle, small range, high inbreeding rate, and numerous opportunities for drug exposure, present even more severe resistance challenges than other crop pests, making them typical r-strategy pests. They disrupt the normal physiological functions of plants, causing leaf, bud, and fruit drop, resulting in yield reductions and weakened growth at best, and even crop failures or even death of the entire plant at worst. Currently, pests are becoming increasingly important pests of fruit trees, vegetables, and agricultural and forestry crops, with nearly all crops being harmed by pests (such as the cinnabarinus spider mite, the two-spotted spider mite, and the hawthorn spider mite). Furthermore, due to the long-standing limited availability of acaricides and their limited variety, resistance to these single acaricides has developed rapidly. To address this issue, new acaricides that target specific sites have been developed in agriculture. However, most of these acaricides are highly toxic and have high residual effects, causing not only environmental pollution but also human health risks.

[0003] Spirodiclofen (Chemical formula C2H4C l2 O) Its mechanism of action is to inhibit fat synthesis in the mite's body, disrupting its energy metabolism and ultimately killing it. Spirodiclofen is known for its broad-spectrum acaricide activity, kills both eggs and larvae, has a long-lasting effect, is low in toxicity, and is safe. However, mites are prone to developing resistance to spirodiclofen. Furthermore, most commercially available acaricides exhibit poor adhesion to plant surfaces, leading to loss of the active ingredient and significantly reducing their effectiveness.

[0004] Therefore, there is a need to find a new type of acaricide to solve the problem that mites easily develop resistance to spirodiclofen, and the problem that acaricides have poor adhesion to plant surfaces when used, resulting in the loss of active ingredients and reduced acaricidal effect. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a miticide and its preparation method and application, so as to solve the current problems that mites are prone to develop resistance to miticides, and miticides have poor adhesion to plant surfaces, resulting in the loss of active ingredients and reduced miticide effect.

[0006] The present invention solves the above technical problems through the following technical means:

[0007] A miticide, the active ingredients of which are spirodiclofen and scoparia lactone.

[0008] Furthermore, the mass ratio of the active ingredients spirodiclofen and scoparia lactone is (9:1)-(1:9).

[0009] Preferably, the mass ratio of the active ingredients spirodiclofen and scoparia lactone is 9:1.

[0010] Scoparone, also known as dimethoxycoumarin, is a coumarin compound that has multiple activities against mites, including contact killing, systemic absorption, repellency, and oviposition inhibition. Mites are very unlikely to develop resistance to scoparone, and it can be used continuously for many years. The inventors of the present invention have found through a large number of experimental studies that when the mass ratio of spirodiclofen to scoparone is (9:1)-(1:9), there is a synergistic effect. Compared with the mite killing effect of using spirodiclofen or scoparone alone, the mite killing effect is significantly improved. When the mass ratio of spirodiclofen to scoparone is 9:1, the effect is the best. Spirodiclofen and scoparone are compounded in a specific ratio and prepared into a miticide, which effectively reduces the drug resistance of mites and improves the mite control effect.

[0011] Furthermore, the acaricide further comprises the following auxiliary materials in parts by weight:

[0012] 30-70 parts of acrylamide, 5-10 parts of glyceraldehyde, 5-10 parts of diphenyl acetylene, 25-40 parts of 60wt% ethanol solution, 2-7 parts of benzoyl peroxide, 20-50 parts of 20wt% 2-phenylethanol solution, 73-103 parts of Tween-85, 60-90 parts of N-methylpyrrolidone, 10-30 parts of 1,2-butanediol, and 570-770 parts of deionized water.

[0013] Furthermore, the mass ratio of the active ingredient to the excipient is (100-200): (800-1000).

[0014] The present invention also discloses a preparation method of the acaricide, and the preparation method is as follows:

[0015] A. Add glyceraldehyde and diphenylacetylene to a 60 wt% ethanol solution and stir evenly, then place in hot water and heat in a water bath. After heating in the water bath, adjust the pH to 7.5-8.5 to obtain a mixed solution, which is set aside;

[0016] B: Add deionized water to acrylamide to prepare an acrylamide solution, then add benzoyl peroxide, transfer to a sealed reactor, react at 55-70°C for 2-3 hours, cool to room temperature, add the mixed solution and continue to react for 3-4 hours to obtain a modified polyacrylamide solution for use;

[0017] C. Mix spirodiclofen and scoparia lactone evenly, then add N-methylpyrrolidone, Tween-85, and 1,2-butanediol, and stir at a speed of 500-800 r / min for 2-5 minutes. Then add 2-phenylethanol solution and stir to mix evenly. Finally, add modified polyacrylamide solution, place in a homogenizer, and homogenize at a pressure of 15-18 MPa for 5-8 minutes to obtain a miticide.

[0018] Polyacrylamide is a harmless polymer with excellent viscosity-increasing properties and is highly effective in improving soil physical and chemical properties. Its biodegradation rate is relatively slow and its action time is long. Adding polyacrylamide as a viscosity-increasing agent to acaricides solves the problem of acaricides having difficulty adhering to plant leaves or the surfaces of infested mites, resulting in a lack of sustained acaricide efficacy. Furthermore, once incorporated into soil, it effectively improves soil physical and chemical properties, achieving multi-effect utilization. However, the high viscosity of polyacrylamide gel can easily clog spraying equipment and nozzles, hindering the release of active substances. Therefore, the present invention adds benzoyl peroxide to acrylamide for cross-linking, ultimately producing polyacrylamide. Simultaneously, a mixed solution is added during the cross-linking process to modify the acaricide. The glyceraldehyde in the mixed solution affects the intermolecular forces of the polyacrylamide generated during the cross-linking process, thereby reducing the viscosity of the polyacrylamide to a certain extent. This allows the acaricide to firmly adhere to plant and mite surfaces while remaining durable. The polyacrylamide prepared by the present invention is not easily diluted by rain or dew, making it suitable for use in various weather conditions and enhancing the effectiveness of the acaricide.

[0019] In addition, the peak period of mite infestation is generally during the hot weather of July and August. In a high temperature environment, the viscosity of polyacrylamide will decrease, making it difficult to adhere, thus affecting the effectiveness of the acaricide. The diphenylacetylene in the mixed liquid further modifies the polyacrylamide, maintains the three-dimensional structure of polyacrylamide, and improves its thermal stability, so that the acaricide can be stably adsorbed on the surface of plants and mites in a high temperature environment, thereby improving the effectiveness of the acaricide in a high temperature environment.

[0020] Add 2-phenylethanol solution to the acaricide to lure mites to the acaricide and kill them. When the mites are lured to the acaricide, the acaricide will adhere to the surface of the mite because of its stickiness. Mites live in groups, and the mites attached to the acaricide will carry the acaricide to the mite colony and then kill other mites, greatly increasing the prevention and control effect.

[0021] Furthermore, in step A, the water bath heating temperature is 45-55° C., and the water bath heating time is 15-20 min.

[0022] The invention also discloses application of the acaricide in preventing and controlling harmful mites.

[0023] Furthermore, the acaricide is used to control one or more of rust mites, tarsonemes, tea yellow mites, cinnabarinus spider mites, and two-spotted spider mites.

[0024] Beneficial effects:

[0025] 1. The present invention uses scoparia lactone and spirodiclofen as active ingredients to prepare acaricides. Scoparia lactone and spirodiclofen act synergistically to effectively improve the acaricidal effect, and mites are less likely to develop drug resistance.

[0026] 2. The present invention modifies acrylamide into a highly stable viscous liquid, which is added to the acaricide, so that the acaricide can adhere well to the plant surface even in a high-temperature environment, thereby solving the problem of poor adhesion of the acaricide, which leads to easy loss of the active ingredients and reduced acaricidal effect.

[0027] 3. The present invention adds a mite attractant to the acaricide to attract mites to the acaricide. The acaricide is prepared into a viscous liquid so that the acaricide adheres to the surface of the attracted mites, allowing them to carry the acaricide to the mite colony to poison other mites, thereby greatly increasing the control effect of mites. DETAILED DESCRIPTION

[0028] The present invention will be described in detail below with reference to specific embodiments:

[0029] Example 1: Preparation of acaricide

[0030] Weigh 135 g of spirodiclofen, 15 g of scoparia lactone, 50 g of acrylamide, 7 g of glyceraldehyde, 7 g of diphenylacetylene, 35 g of 60 wt% ethanol solution, 5 g of benzoyl peroxide, 40 g of 20 wt% 2-phenylethanol solution, 90 g of Tween-85, 80 g of N-methylpyrrolidone, 20 g of 1,2-butanediol, and 620 g of deionized water.

[0031] Preparation method:

[0032] A. Add glyceraldehyde and diphenylacetylene to a 60 wt% ethanol solution and stir evenly. Then, heat in a 50°C water bath for 17 minutes. After heating in the water bath, adjust the pH to 8 to obtain a mixed solution, which is then set aside.

[0033] B. Add deionized water to acrylamide to prepare an acrylamide solution, then add benzoyl peroxide, transfer to a sealed reactor, react at 65°C for 3 hours, cool to room temperature, add the mixed solution and continue to react for 3 hours to obtain a modified polyacrylamide solution for later use;

[0034] C. Mix spirodiclofen and scoparia lactone evenly, then add N-methylpyrrolidone, Tween-85, and 1,2-butanediol, and stir at a speed of 600 r / min for 3 minutes. Then add 2-phenylethanol solution and stir to mix evenly. Finally, add modified polyacrylamide solution, put into a homogenizer, and homogenize at a pressure of 17 MPa for 6 minutes to obtain a miticide.

[0035] Example 2: Preparation of acaricide II

[0036] Weigh 90 g of spirodiclofen, 10 g of scoparia lactone, 30 g of acrylamide, 5 g of glyceraldehyde, 5 g of diphenylacetylene, 25 g of 60 wt% ethanol solution, 5 g of benzoyl peroxide, 20 g of 20 wt% 2-phenylethanol solution, 70 g of Tween-85, 60 g of N-methylpyrrolidone, 10 g of 1,2-butanediol, and 720 g of deionized water.

[0037] Preparation method:

[0038] A. Add glyceraldehyde and diphenylacetylene to a 60 wt% ethanol solution and stir evenly. Then, heat in a 45°C water bath for 15 minutes. After heating in the water bath, adjust the pH to 7.5 to obtain a mixed solution, which is then set aside.

[0039] B. Add deionized water to acrylamide to prepare an acrylamide solution, then add benzoyl peroxide, transfer to a sealed reactor, react at 55°C for 2 hours, cool to room temperature, add the mixed solution and continue to react for 4 hours to obtain a modified polyacrylamide solution for use;

[0040] C. Mix spirodiclofen and scoparia lactone evenly, then add N-methylpyrrolidone, Tween-85, and 1,2-butanediol, and stir at a speed of 500 r / min for 2 minutes. Then add 2-phenylethanol solution and stir to mix evenly. Finally, add modified polyacrylamide solution, put into a homogenizer, and homogenize at a pressure of 15 MPa for 5 minutes to obtain a miticide.

[0041] Example 3: Preparation of acaricide

[0042] Weigh 180 g of spirodiclofen, 20 g of scoparia lactone, 70 g of acrylamide, 10 g of glyceraldehyde, 10 g of diphenylacetylene, 40 g of 60 wt% ethanol solution, 10 g of benzoyl peroxide, 50 g of 20 wt% 2-phenylethanol solution, 100 g of Tween-85, 90 g of N-methylpyrrolidone, 30 g of 1,2-butanediol, and 580 g of deionized water.

[0043] Preparation method:

[0044] A. Add glyceraldehyde and diphenylacetylene to a 60 wt% ethanol solution and stir evenly. Then, heat in a 55°C water bath for 20 minutes. After heating in the water bath, adjust the pH to 8.5 to obtain a mixed solution, which is then set aside.

[0045] B. Add deionized water to acrylamide to prepare an acrylamide solution, then add benzoyl peroxide. Transfer the mixture to a sealed reactor, react at 70°C for 2 hours, then cool to room temperature. Add the mixed solution and continue reacting for 4 hours to obtain a modified polyacrylamide solution for later use.

[0046] C. Mix spirodiclofen and scoparia lactone evenly, then add N-methylpyrrolidone, Tween-85, and 1,2-butanediol, and stir at a speed of 800 r / min for 5 minutes. Then add 2-phenylethanol solution and stir to mix evenly. Finally, add modified polyacrylamide solution, put into a homogenizer, and homogenize at a pressure of 18 MPa for 8 minutes to obtain a miticide.

[0047] Comparative Example 1: Preparation of acaricide

[0048] A comparative example is formed with Example 1, the only difference being that glyceraldehyde is not added during the preparation of the acaricide in Comparative Example 1.

[0049] Weigh 135 g of spirodiclofen, 15 g of scoparia lactone, 50 g of acrylamide, 7 g of diphenylacetylene, 35 g of 60 wt% ethanol solution, 5 g of benzoyl peroxide, 40 g of 20 wt% 2-phenylethanol solution, 90 g of Tween-85, 80 g of N-methylpyrrolidone, 20 g of 1,2-butanediol, and 620 g of deionized water.

[0050] Preparation method:

[0051] A. Add diphenylacetylene to a 60 wt% ethanol solution and stir evenly. Then, heat in a 50°C water bath for 17 minutes. After heating in the water bath, adjust the pH to 8 to obtain a mixed solution, which is then set aside.

[0052] B. Add deionized water to acrylamide to prepare an acrylamide solution, then add benzoyl peroxide, transfer to a sealed reactor, react at 65°C for 3 hours, cool to room temperature, add the mixed solution and continue to react for 3 hours to obtain a modified polyacrylamide solution for later use;

[0053] C. Mix spirodiclofen and scoparia lactone evenly, then add N-methylpyrrolidone, Tween-85, and 1,2-butanediol, and stir at a speed of 600 r / min for 3 minutes. Then add 2-phenylethanol solution and stir to mix evenly. Finally, add modified polyacrylamide solution, put into a homogenizer, and homogenize at a pressure of 17 MPa for 6 minutes to obtain a miticide.

[0054] Comparative Example 2: Preparation of acaricide

[0055] A comparative example is formed with Example 1, the only difference being that no diphenylacetylene is added during the preparation of the acaricide in Comparative Example 2.

[0056] Weigh 135 g of spirodiclofen, 15 g of scoparia lactone, 50 g of acrylamide, 7 g of glyceraldehyde, 35 g of 60 wt% ethanol solution, 5 g of benzoyl peroxide, 40 g of 20 wt% 2-phenylethanol solution, 90 g of Tween-85, 80 g of N-methylpyrrolidone, 20 g of 1,2-butanediol, and 620 g of deionized water.

[0057] Preparation method:

[0058] A. Add glyceraldehyde to a 60 wt% ethanol solution and stir evenly. Then, heat in a 50°C water bath for 17 minutes. After heating in the water bath, adjust the pH to 8 to obtain a mixed solution, which is set aside.

[0059] B. Add deionized water to acrylamide to prepare an acrylamide solution, then add benzoyl peroxide, transfer to a sealed reactor, react at 65°C for 3 hours, cool to room temperature, add the mixed solution and continue to react for 3 hours to obtain a modified polyacrylamide solution for later use;

[0060] C. Mix spirodiclofen and scoparia lactone evenly, then add N-methylpyrrolidone, Tween-85, and 1,2-butanediol, and stir at a speed of 600 r / min for 3 minutes. Then add 2-phenylethanol solution and stir to mix evenly. Finally, add modified polyacrylamide solution, put into a homogenizer, and homogenize at a pressure of 17 MPa for 6 minutes to obtain a miticide.

[0061] Comparative Example 3: Preparation of acaricide

[0062] A comparative example is formed with Example 1, the only difference being that no scoparia lactone is added during the preparation of the acaricide in Comparative Example 3, and only spiroclofonate is used.

[0063] Weigh 150 g of spirodiclofen, 50 g of acrylamide, 7 g of glyceraldehyde, 7 g of diphenylacetylene, 35 g of 60 wt% ethanol solution, 5 g of benzoyl peroxide, 40 g of 20 wt% 2-phenylethanol solution, 90 g of Tween-85, 80 g of N-methylpyrrolidone, 20 g of 1,2-butanediol, and 620 g of deionized water.

[0064] Preparation method:

[0065] A. Add glyceraldehyde and diphenylacetylene to a 60 wt% ethanol solution and stir evenly. Then, heat in a 50°C water bath for 17 minutes. After heating in the water bath, adjust the pH to 8 to obtain a mixed solution, which is then set aside.

[0066] B. Add deionized water to acrylamide to prepare an acrylamide solution, then add benzoyl peroxide, transfer to a sealed reactor, react at 65°C for 3 hours, cool to room temperature, add the mixed solution and continue to react for 3 hours to obtain a modified polyacrylamide solution for later use;

[0067] C. Mix spirodiclofen with N-methylpyrrolidone, Tween-85, and 1,2-butanediol, and stir at 600 r / min for 3 minutes. Then add 2-phenylethanol solution and stir to mix evenly. Finally, add modified polyacrylamide solution, place in a homogenizer, and homogenize at a pressure of 17 MPa for 6 minutes to obtain the acaricide.

[0068] Comparative Example 4: Preparation of acaricide

[0069] A comparative example is formed with Example 1, the only difference being that spirodiclofen is not added during the preparation of the acaricide in Comparative Example 4, and only scoparia lactone is used.

[0070] Weigh 150 g of artemisinin, 50 g of acrylamide, 7 g of glyceraldehyde, 7 g of diphenylacetylene, 35 g of 60 wt% ethanol solution, 5 g of benzoyl peroxide, 40 g of 20 wt% 2-phenylethanol solution, 90 g of Tween-85, 80 g of N-methylpyrrolidone, 20 g of 1,2-butanediol, and 620 g of deionized water.

[0071] Preparation method:

[0072] A. Add glyceraldehyde and diphenylacetylene to a 60 wt% ethanol solution and stir evenly. Then, heat in a 50°C water bath for 17 minutes. After heating in the water bath, adjust the pH to 8 to obtain a mixed solution, which is then set aside.

[0073] B. Add deionized water to acrylamide to prepare an acrylamide solution, then add benzoyl peroxide, transfer to a sealed reactor, react at 65°C for 3 hours, cool to room temperature, add the mixed solution and continue to react for 3 hours to obtain a modified polyacrylamide solution for later use;

[0074] C. Mix artemisinin with N-methylpyrrolidone, Tween-85, and 1,2-butanediol, stir at a speed of 600 r / min for 3 minutes, then add 2-phenylethanol solution and stir to mix evenly, finally add modified polyacrylamide solution, put into a homogenizer, and homogenize at a pressure of 17 MPa for 6 minutes to obtain a miticide.

[0075] Comparative Example 5: Preparation of acaricide

[0076] A comparative example is formed with Example 1, the only difference being that the pH of the mixed solution is not adjusted during the preparation of the acaricide in Comparative Example 5.

[0077] Weigh 135 g of spirodiclofen, 15 g of scoparia lactone, 50 g of acrylamide, 7 g of glyceraldehyde, 7 g of diphenylacetylene, 35 g of 60 wt% ethanol solution, 5 g of benzoyl peroxide, 40 g of 20 wt% 2-phenylethanol solution, 90 g of Tween-85, 80 g of N-methylpyrrolidone, 20 g of 1,2-butanediol, and 620 g of deionized water.

[0078] Preparation method:

[0079] A. Add glyceraldehyde and diphenylacetylene to a 60 wt% ethanol solution and stir evenly. Then heat in a 50°C water bath for 17 minutes to obtain a mixed solution for later use.

[0080] B. Add deionized water to acrylamide to prepare an acrylamide solution, then add benzoyl peroxide, transfer to a sealed reactor, react at 65°C for 3 hours, cool to room temperature, add the mixed solution and continue to react for 3 hours to obtain a modified polyacrylamide solution for later use;

[0081] C. Mix spirodiclofen and scoparia lactone evenly, then add N-methylpyrrolidone, Tween-85, and 1,2-butanediol, and stir at a speed of 600 r / min for 3 minutes. Then add 2-phenylethanol solution and stir to mix evenly. Finally, add modified polyacrylamide solution, put into a homogenizer, and homogenize at a pressure of 17 MPa for 6 minutes to obtain a miticide.

[0082] Comparative Example 6: Preparation of acaricide

[0083] In contrast to Example 1, the only difference is that in the preparation of the acaricide in Comparative Example 6, acrylamide is replaced by polyvinyl alcohol solution in step B, and benzoyl peroxide is not added for the reaction.

[0084] Weigh 135g of spirodiclofen, 15g of scoparia lactone, 50g of polyvinyl alcohol, 7g of glyceraldehyde, 7g of diphenyl acetylene, 35g of 60wt% ethanol solution, 40g of 20wt% 2-phenylethanol solution, 90g of Tween-85, 80g of N-methylpyrrolidone, 20g of 1,2-butanediol, and 620g of deionized water.

[0085] A. Add glyceraldehyde and diphenylacetylene to a 60 wt% ethanol solution and stir evenly. Then, heat in a 50°C water bath for 17 minutes. After heating in the water bath, adjust the pH to 8 to obtain a mixed solution, which is then set aside.

[0086] B. Add deionized water to polyvinyl alcohol to prepare a polyvinyl alcohol solution, add the mixed solution and react at room temperature for 3 hours to obtain a modified polyvinyl alcohol solution for use;

[0087] C. Mix spirodiclofen and scoparia lactone evenly, then add N-methylpyrrolidone, Tween-85, and 1,2-butanediol, and stir at 600 r / min for 3 minutes. Then add 2-phenylethanol solution and stir to mix evenly. Finally, add modified polyvinyl alcohol solution, put into a homogenizer, and homogenize at a pressure of 17 MPa for 6 minutes to obtain a miticide.

[0088] Comparative Example 7: Preparation of acaricide

[0089] A comparative example is formed with Example 1, the only difference being that in the preparation of the acaricide in Comparative Example 7, no mixed liquid is added in step B to modify the polyacrylamide.

[0090] Weigh 135 g of spirodiclofen, 15 g of scoparia lactone, 50 g of acrylamide, 5 g of benzoyl peroxide, 40 g of 20 wt% 2-phenylethanol solution, 90 g of Tween-85, 80 g of N-methylpyrrolidone, 20 g of 1,2-butanediol, and 620 g of deionized water.

[0091] Preparation method:

[0092] A. Add deionized water to acrylamide to prepare an acrylamide solution, then add benzoyl peroxide. Transfer the mixture to a sealed reactor, react at 65°C for 3 hours, and then cool to room temperature to obtain a polyacrylamide solution for later use.

[0093] B. Mix spirodiclofen and scoparia lactone evenly, then add N-methylpyrrolidone, Tween-85, and 1,2-butanediol, and stir at 600 r / min for 3 minutes. Then add 2-phenylethanol solution and stir to mix evenly. Finally, add polyacrylamide solution, put into a homogenizer, and homogenize at a pressure of 17 MPa for 6 minutes to obtain the acaricide.

[0094] Comparative Example 8: Preparation of acaricide

[0095] A comparative example is formed with Example 1, the only difference being that the acaricide in Comparative Example 8 is not prepared according to the method of the present invention, but spirodiclofen is selected and prepared according to a conventional method, specifically as follows:

[0096] Weigh 150 g of spirodiclofen, 90 g of Tween-85, 80 g of N-methylpyrrolidone, 20 g of 1,2-butanediol, and 620 g of deionized water.

[0097] Spirodiclofen, N-methylpyrrolidone and 1,2-butanediol were stirred and mixed evenly, and then Tween-85 and deionized water were added into the mixture, and the mixture was put into a homogenizer under a pressure of 17 MPa and homogenized for 6 minutes to obtain a miticide.

[0098] Experiment 1: Thermal stability performance test

[0099] 50 g of each of the acaricides prepared in Example 1, Comparative Examples 1-2, and Comparative Examples 5-7 were taken, and their viscosities at 15°C, 25°C, 35°C, and 45°C were measured in mPa·s. The obtained data are shown in Table 1:

[0100] Table 1

[0101] Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 5 Comparative Example 6 Comparative Example 7 Viscosity at 15°C 473 648 471 587 446 643 Viscosity at 25°C 468 632 421 538 422 587 Viscosity at 35°C 457 597 376 465 405 498 Viscosity at 45°C 442 549 302 389 377 401

[0102] According to the data analysis in Table 1, we can see that:

[0103] (1) The acaricide prepared in Example 1 has a more suitable viscosity than Comparative Examples 1-2 and Comparative Examples 5-7, and the viscosity changes less with increasing temperature, indicating that the acaricide prepared in Example 1 is highly stable at high temperatures. In Comparative Example 1, the acaricide was prepared without the addition of glyceraldehyde to treat the polyacrylamide, which resulted in excessive intermolecular forces between the polyacrylamide molecules and increased viscosity of the prepared acaricide.

[0104] (2) In Comparative Example 2, no diphenylacetylene was added to modify the polyacrylamide during the preparation of the acaricide, which failed to better maintain the three-dimensional structural stability of the polyacrylamide, resulting in poor thermal stability. As the temperature increased, the viscosity decreased rapidly;

[0105] (3) In Comparative Example 5, the pH of the mixed solution was not adjusted during the preparation of the acaricide, resulting in relatively large molecular forces during the preparation of polyacrylamide, strong viscosity, and poor three-dimensional structural stability. As the temperature increased, the viscosity decreased rapidly;

[0106] (4) In comparative example 6, acrylamide was replaced with polyvinyl alcohol during the preparation of the acaricide, resulting in poor viscosity;

[0107] (5) In Comparative Example 7, the mixed solution was not added during the reaction when the acaricide was prepared. The intermolecular force of polyacrylamide was large, the viscosity was high, and the three-dimensional structure was unstable. As the temperature increased, the viscosity decreased rapidly. This shows that the modification of acrylamide by the method of the present invention can reduce the viscosity of polyacrylamide to a certain extent, so that it can better adhere to the surface of plants without affecting the spraying operation, and effectively improve its stability, so that the acaricide can also well adhere to the surface of crops and kill mites in a high temperature environment, thereby improving the effect of the acaricide.

[0108] Experiment 2: Indoor toxicity test of acaricides against Tetranychus cinnabarinus

[0109] 1. The acaricides prepared in Example 1 and Comparative Examples 1, 3, 4 and 8 were subjected to an indoor toxicity test on Tetranychus cinnabarinus. The experiment was divided into 6 groups: experimental group 1, control group 1, control group 3, control group 4, control group 8 and blank control group.

[0110] 2. Experimental subjects: Adult mites of Tetranychus cinnabarinus were collected from the fields of Beibei and cultured in the laboratory for a long time.

[0111] 3. Acaricide

[0112] Experimental group 1: the acaricide prepared in Example 1 was used;

[0113] Control group 1: the acaricide prepared in comparative example 1 was selected;

[0114] Control group 3: the acaricide prepared in comparative example 3 was selected;

[0115] Control group 4: the acaricide prepared in comparative example 4 was selected

[0116] Control group 8: the acaricide prepared in comparative example 8 was selected;

[0117] Blank control group: clean water was used as the control.

[0118] 4. Experimental Method: 120 female adult mites of uniform growth and vitality were selected and divided into 6 groups, 20 in each group. They were placed on the back of leaves in potted pea seedlings for 4 hours. After the mites were established, the corresponding acaricide was sprayed on the surface of the pea seedlings at a rate of 15g per pot. After 8 hours, 500g / pot of clean water was sprayed to simulate rainwater erosion. The mortality of the mites was checked 24 hours and 48 hours after the treatment. The mite legs were touched with a fine brush. If there was no reaction, it was considered dead. The mortality rate of each group of spider mites was calculated. This was repeated three times, and the results are shown in Table 2:

[0119] Table 2

[0120]

[0121]

[0122] According to the data analysis in Table 2:

[0123] (1) The acaricide prepared in experimental group 1 had a good acaricidal effect on mites. The mortality rates of Tetranychus cinnabarinus in control group 3 at 24 h and 48 h were 15% and 25% lower than those in experimental group 1, respectively. This was because the acaricide in control group 3 was not added with scoparia lactone during preparation, and the active ingredient was only spirodiclofen, which failed to increase the acaricidal effect of spirodiclofen, resulting in a reduced acaricidal effect.

[0124] (2) The 24-hour and 48-hour mortality rates of Tetranychus cinnabarinus in control group 4 were 10% and 20% lower than those in experimental group 1, respectively. This was because spirodiclofen was not added to the acaricide in control group 4, and the active ingredient was only artemisinin. A single active ingredient had no synergistic effect, resulting in a reduced acaricidal effect.

[0125] (3) The 24h and 48h mortality rates of Tetranychus cinnabarinus in control group 8 were 20% and 35% lower than those in experimental group 1, respectively. This was because only spirodiclofen was used alone in the preparation of the acaricide in control group 8, which failed to achieve a synergistic acaricidal effect. In addition, the acaricide was prepared according to conventional methods, and the prepared acaricide had poor adhesion to the plant surface and was lost under the erosion of rainwater, resulting in poor acaricidal effect. This indicates that the acaricide was prepared using spirodiclofen and artemisinin as active ingredients, so that spirodiclofen and artemisinin acted synergistically, which could improve the acaricidal effect. The acaricide was prepared into a liquid with good viscosity, which could make the acaricide adhere to the surface of crops and mites to effectively kill mites, greatly improving the prevention and control effect of mites, and solving the problem that the acaricide had poor adhesion to the plant surface and the effective ingredients were easily lost, resulting in reduced acaricidal effect.

[0126] The above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art will appreciate that the technical solutions of the present invention may be modified or replaced with equivalents without departing from the spirit and scope of the technical solutions of the present invention, and such modifications or equivalents shall be encompassed by the claims of the present invention. Any techniques, shapes, and structures not described in detail herein are well known.

Claims

1. A miticide, characterized in that: The active ingredients of the acaricide are spirodiclofen and scoparia lactone; the mass ratio of the active ingredients spirodiclofen to scoparia lactone is 9:

1.

2. The acaricide according to claim 1, characterized in that The acaricide further comprises the following auxiliary materials in parts by weight: 30-70 parts of acrylamide, 5-10 parts of glyceraldehyde, 5-10 parts of diphenyl acetylene, 25-40 parts of 60wt% ethanol solution, 2-7 parts of benzoyl peroxide, 20-50 parts of 20wt% 2-phenylethanol solution, 73-103 parts of Tween-85, 60-90 parts of N-methylpyrrolidone, 10-30 parts of 1,2-butanediol, and 570-770 parts of deionized water; The mass ratio of the active ingredient to the excipient is 100-200:800-1000.

3. The method for preparing an acaricide according to claim 2, characterized in that: The preparation method of the acaricide is as follows: A. Add glyceraldehyde and diphenylacetylene to a 60 wt% ethanol solution and stir evenly, then place in hot water and heat in a water bath. After heating in the water bath, adjust the pH to 7.5-8.5 to obtain a mixed solution, which is set aside; B: Add deionized water to acrylamide to prepare an acrylamide solution, then add benzoyl peroxide, transfer to a sealed reactor, react at 55-70°C for 2-3 hours, cool to room temperature, add the mixed solution and continue to react for 3-4 hours to obtain a modified polyacrylamide solution for use; C. Mix spirodiclofen and scoparia lactone uniformly, then add N-methylpyrrolidone, Tween-85, and 1,2-butanediol, and stir at 500-800 rpm for 2-5 minutes. Then, add 2-phenylethanol solution and stir until uniformly mixed. Finally, add modified polyacrylamide solution, place in a homogenizer, and homogenize at 15-18 MPa for 5-8 minutes to obtain the acaricide. In step A, the water bath heating temperature is 45-55° C., and the water bath heating time is 15-20 minutes.

4. The use of an acaricide according to any one of claims 1-2, characterized in that: The application is the application of the acaricide in preventing and controlling harmful mites; the harmful mite is Tetranychus cinnabarinus.

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