Biopesticide for preventing and treating citrus red mites

Abstract

The invention belongs to the technical field of pesticides, and particularly relates to a biopesticide for preventing and treating citrus red mites. The invention relates to a biopesticide. The biopesticide is prepared by compounding emodin and abamectin or osthole. When the emodin and the abamectin or the cnidium lactone are combined and compounded, the emodin and the abamectin or the cnidium lactone show a synergistic interaction effect on the citrus red mites, the prevention and treatment effect on the citrus red mites can be improved, the problems caused by long-term use of the same medicament or the same medicament can be relieved, meanwhile, the generation and development of the drug resistance of the citrus red mites can be delayed, and the prevention and treatment effect on the citrus red mites is improved. And support is provided for comprehensive treatment of drug resistance. Secondly, emodin, abamectin and osthole are biopesticide components, are environmentally friendly and can provide support for developing biopesticides for preventing and treating citrus red mites.

Description

Technical Field

[0001] The invention belongs to the technical field of pesticides, and particularly relates to a biological pesticide for preventing and controlling citrus red spider mites. Background Art

[0002] Citrus red spider mites (Tetranychus cinnbarinus), belonging to the Arachnidae, Acari, Tetranychus family, are a major pest in citrus production and management. They feed on sap and damage tender shoots, leaves, and fruit peels, with the leaves being the most severely affected. Infected leaves develop grayish-white spots. In severe cases, the entire leaf turns grayish-white, and leaves and fruit may even fall, severely impacting citrus tree vigor and yield.

[0003] Chemical control has long been the primary approach for controlling citrus spider mites, with commonly used agents including abamectin, spirocyclofen, pyridaben, and cyflumetofen. However, repeated, excessive, and long-term, continuous use of the same class of agents, or even the same agent, in production can lead to the rapid development of resistance in citrus spider mites, resulting in reduced control effectiveness or even ineffectiveness. Therefore, the use of agents with combined synergistic properties is crucial for controlling citrus spider mites. Furthermore, for some citrus varieties, such as tangerine peel, tea-branch orange, and kumquat, whose peels can be used as medicine or eaten fresh, low-residue, environmentally friendly biopesticides should be used.

[0004] Abamectin is a class of 16-membered macrolide biopesticides with insecticidal, acaricidal, and nematicidal activity. It is produced by fermentation of Streptomyces avermitilis. Abamectin has stomach and contact toxicity against mites and insects. Its mechanism of action differs from that of general insecticides in that it interferes with neurophysiological activity, stimulating the release of gamma-aminobutyric acid, which inhibits nerve conduction in arthropods. Adult mites, nymphs, and insect larvae experience paralysis upon contact with avermectin, becoming inactive and refusing to feed, ultimately dying after 2-4 days.

[0005] Osthole is a botanical pesticide extracted from the fruit of Cnidium monnieri, an annual herbaceous plant in the Apiaceae family. It possesses the active pesticide gene, an isopentenyl structure, and exhibits unique insecticidal and antibacterial activity. Osthole's insecticidal effect is primarily contact-killing, supplemented by stomach-toxicity. The liquid is absorbed into the insect's body through the surface and acts on its nervous system, causing non-functional muscle contractions and ultimately exhaustion and death. It has strong contact-killing activity against a variety of pests, including cabbage worms, tea loopers, cotton bollworms, and various aphids.

[0006] The prior art discloses that the quinone compound emodin (CAS: 518-82-1) has good insecticidal activity against brown planthoppers. Studies have found that the insecticidal mode of emodin may be related to the inhibitory activity of AChE and GST. By inhibiting the activity of the above two enzymes, it causes nerve conduction and motor dysfunction in the insect body and inactivates the insect body's detoxification function, thereby leading to the death of the brown planthopper.

[0007] At present, there are no reports on the combination of emodin with avermectin or osthole. Summary of the Invention

[0008] The purpose of the present invention is to provide a biological pesticide for controlling citrus red spider mites, so as to solve the problem that repeated, excessive, long-term and continuous use of the same type of agent, or even the same agent, in production leads to rapid development of drug resistance in citrus red spider mites, resulting in low control efficiency or even ineffectiveness.

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

[0010] A biological pesticide is prepared by compounding emodin with abamectin or osthole.

[0011] More specifically, the mass ratio of emodin to avermectin is 1-20:20-1.

[0012] More specifically, the mass ratio of emodin to osthole is 1-7:15-1.

[0013] More specifically, the mass ratio of emodin to osthole is 1:7.

[0014] The present invention also provides the use of the biological pesticide in preventing and controlling citrus red spider mites.

[0015] The present invention also provides a biopesticide preparation, which is prepared by using the biopesticide as an active ingredient and supplemented with auxiliary ingredients permitted to be added in pesticide science.

[0016] More specifically, the formulation of the biopesticide preparation includes granules.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) When emodin is combined with abamectin or osthole in the present invention, a synergistic effect is exhibited on citrus red spider mites, which can improve the control effect on citrus red spider mites, help alleviate the problems caused by long-term use of the same type of agents or the same agent, and at the same time delay the generation and development of drug resistance in citrus red spider mites, providing support for comprehensive drug resistance management.

[0019] (2) The emodin, abamectin and osthole of the present invention are all biological pesticide ingredients, which are environmentally friendly and green, and can provide support for the development of biological pesticides for controlling citrus red spider mites. DETAILED DESCRIPTION

[0020] The following is a clear and complete description of the technical solution of the present invention. Obviously, the embodiments described are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of the present invention.

[0021] Example :Indoor biological testing

[0022] 1. Test agent

[0023] 95% emodin technical (CAS: 518-82-1), 94% avermectin technical, 98% osthole technical.

[0024] After dissolving the original drug, dilute it with 0.1% Tween-80 aqueous solution to form a single-dose stock solution. Set multiple groups of ratios according to the preliminary test results, and then dilute each single-dose stock solution and each group of mixed ratios with 0.1% Tween-80 aqueous solution to 5 mass concentration gradients for use.

[0025] 2. Test insect sources

[0026] Citrus red spider mites were collected from citrus plantations and brought back to the laboratory for continuous rearing for five generations. Female adult mites of uniform size were selected as the test insect source.

[0027] 3. Test methods

[0028] The slide immersion method recommended by the Food and Agriculture Organization of the United Nations was used to determine the biological activity of each single agent and mixed agent against citrus red spider mites. Specifically, a double-sided tape with a width of 1 cm and a length of 2.5 cm was attached to one end of a glass slide. A brush was dipped in water and the test insect source was picked up and its back was attached to the double-sided tape. Three rows of 10 insects were attached to each glass slide, for a total of 30 insects. The insects were placed in a container lined with a wet sponge and placed at 25±1°C for 2 hours. After microscopic examination, dead and injured individuals were removed and 30 insects were added to each glass slide. The glass slide with the test insect source was immersed in the test solution, gently shaken for 5 seconds, and then removed and the excess solution was absorbed with absorbent paper. Each treatment was repeated 4 times, and a 0.1% Tween-80 aqueous solution was used as a blank control.

[0029] The treated test insect sources were transferred to an artificial incubator at 25±1℃, relative humidity 75±5%, and photoperiod 16L / 8D for breeding. After 48 hours, the death of the test insects was investigated (the mite body was touched lightly with a brush, and the mite legs were considered dead if they did not move). The total number of insects and the number of dead insects in each treatment were recorded respectively, and the adjusted mortality rate of each treatment was calculated.

[0030]

[0031] In the above formula: P is the mortality rate, in %; K is the number of dead insects; N is the total number of insects treated.

[0032]

[0033] In the above formula: P1--corrected mortality rate, unit is %; P t --Treatment mortality, unit is %; P0--blank control mortality, unit is %.

[0034] 4. Data Analysis

[0035] Regression analysis was performed on the logarithmic values of the concentration of each treatment agent and the corrected mortality probability value to calculate the LC of each treatment agent. 50 The co-toxicity coefficient (CTC value) of the mixture was calculated using the Sun Yunpei method.

[0036] The type of combined action of the drugs was evaluated based on the calculated co-toxicity coefficient (CTC): CTC ≤ 80 was antagonistic, 80 < CTC < 120 was additive, and CTC ≥ 120 was synergistic. The results are shown in Table 1-2.

[0037] Table 1 Indoor bioactivity test results of the combination of emodin and avermectin against citrus red spider mites

[0038]

[0039] As shown in Table 1, when emodin and avermectin are combined in a mass ratio of 1-20:20-1, the co-toxicity coefficients of the combination against citrus red spider mites are 125.697-374.027, all greater than 120, demonstrating a synergistic effect. This indicates that the combined combination of emodin and avermectin in the present invention can enhance the control effect against citrus red spider mites.

[0040] Table 2 Indoor bioactivity test results of the complex of emodin and osthole against citrus red spider mites

[0041] Drug name and ratio <![CDATA[LC 50 (mg / L)]]> ATI TTI CTC Rhamnolide 147.862 100.000 -- -- Osthole 15.069 981.233 -- -- Rheum officinale 1: Osthole 15 9.587 1542.318 926.156 166.529 Rhamnolide 1: Osthole 7 3.604 4102.719 871.079 470.993 Rhamnolide 1: Osthole 3 7.849 1883.832 760.925 247.571 Rhamnolide 1: Osthole 1 18.476 800.292 540.616 148.033 Rhamnolide 3: Osthole 1 36.794 401.864 320.308 125.462 Rhamnolide 7: Osthole 1 42.663 346.581 210.154 164.918

[0042] As shown in Table 2, when emodin and osthole are combined in a mass ratio of 1-7:15-1, the combined combination has a co-toxicity coefficient against citrus spider mites ranging from 125.462 to 470.993, all greater than 120, demonstrating a synergistic effect. In particular, when the mass ratio is 1:7, the co-toxicity coefficient reaches 470.993, demonstrating the most significant synergistic effect. This demonstrates that the combined combination of emodin and osthole according to the present invention can enhance the control of citrus spider mites.

[0043] In summary, when emodin is combined with abamectin or osthole in the present invention, a synergistic effect is exhibited on citrus red spider mites, which can improve the control effect on citrus red spider mites, help alleviate the problems caused by long-term use of the same type of agents or the same agent, and at the same time delay the generation and development of drug resistance in citrus red spider mites, providing support for drug resistance management.

Claims

1. A biological pesticide, characterized in that: The biological pesticide is prepared by compounding emodin with abamectin or osthole.

2. The biopesticide according to claim 1, characterized in that The mass ratio of the emodin to the avermectin is 1-20:20-1.

3. The biopesticide according to claim 1, characterized in that The mass ratio of emodin to osthole is 1-7:15-1.

4. The biopesticide according to claim 1, characterized in that The mass ratio of emodin to osthole is 1:

7.

5. Use of the biological pesticide according to any one of claims 1 to 4 in controlling citrus red spider mites.

6. A biopesticide preparation, characterized in that: The biopesticide preparation is prepared by using the biopesticide according to any one of claims 1 to 4 as an active ingredient and supplemented with auxiliary ingredients permitted in pesticide science.

7. The biopesticide preparation according to claim 6, characterized in that The dosage form of the biopesticide preparation includes granules.

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