A cotton aphid control drug composition and drug formulation

Abstract

This invention belongs to the field of pest control technology, specifically relating to a drug composition and formulation for controlling cotton aphids. The drug composition comprises eucalyptol and flonicamid, with a mass ratio of eucalyptol to flonicamid of (8-32):1. This drug composition exhibits a synergistic effect in killing cotton aphids. The combined drug of eucalyptol and flonicamid in the above-mentioned mass ratio shows significantly higher killing efficacy against cotton aphids than either drug alone, and this effect is not additive.

Description

Technical Field

[0001] This invention belongs to the field of pest control technology, specifically relating to a drug composition and drug preparation for controlling cotton aphids. Background Technology

[0002] With the advancement of intensive agricultural production, chemical pesticides have become central to the control of pests, diseases, and weeds. However, the long-term reliance on insecticides with single active ingredients has gradually revealed significant limitations. These pesticides generally suffer from a narrow insecticidal spectrum and a single target, leading to unstable control effects. At the same time, to achieve ideal control efficacy, higher dosages are required, which not only increases agricultural production costs but also easily triggers the rapid evolution of pesticide resistance in pests, exacerbating environmental pollution problems such as soil heavy metal accumulation and water eutrophication, which contradicts the goals of green and sustainable agricultural development.

[0003] Cotton aphids, a global agricultural pest, face significant challenges due to pesticide resistance, which has become a key bottleneck restricting agricultural production. Cotton aphids are characterized by short reproductive cycles, large populations, and strong ecological adaptability, enabling them to rapidly adapt to pesticide pressure through various mechanisms such as gene mutation, enhanced metabolic enzyme activity, and target site mutation. Currently, cotton aphids have developed high levels of resistance to many traditional insecticides, including organophosphates, carbamates, pyrethroids, and neonicotinoids. Even novel insecticides with new mechanisms of action promoted in recent years face the risk of resistance due to long-term single-use, leading to a significant decrease in field control effectiveness. In severe cases, this can cause cotton yield reductions of over 30%, directly threatening the yield and quality safety of agricultural products.

[0004] Therefore, it is necessary to develop an insecticide that can effectively control cotton aphids. Summary of the Invention

[0005] Based on this, the present invention has verified that eucalyptol and flonicamid at a mass ratio of (8-32):1 have a synergistic effect on the killing of cotton aphids, and can be used in combination for the control of cotton aphids.

[0006] To achieve the above objectives, the present invention can adopt the following technical solutions:

[0007] In a first aspect, the present invention provides a cotton aphid control drug composition comprising eucalyptol and flonicamid, wherein the mass ratio of eucalyptol to flonicamid is (8-32):1.

[0008] It should be noted that eucalyptol is a monoterpenoid compound extracted and refined from the branches and leaves of eucalyptus trees. It is a broad-spectrum insecticide of plant origin. It can directly inhibit the synthesis of acetylcholinesterase in insects, hindering the conduction of the nervous system. At the same time, it destroys the body wall of pests, interferes with their water metabolism, and leads to the death of the insects. Due to its green, low-toxicity, and easily degradable characteristics, its application in the field of plant protection is receiving increasing attention. Flupyradifurone is a sulfonamide insecticide that acts on the insect nervous system, that is, it exerts its insecticidal function by acting on a unique binding site in cholinergic receptors. It is suitable for controlling piercing-sucking pests such as mirid bugs, aphids, planthoppers, and scale insects. This insecticide has the advantages of high efficiency, low toxicity, low residue, good systemic properties, and safety for non-target organisms. However, the development of resistance to flonicamid in some pests, such as cotton aphids, has become an important problem.

[0009] More preferably, in the above-mentioned cotton aphid control drug composition, the mass ratio of eucalyptol to flonicamid is 8:1.

[0010] In a second aspect, the present invention provides a cotton aphid control drug formulation comprising the above-mentioned cotton aphid control drug composition.

[0011] Preferably, the formulation of the above-mentioned cotton aphid control drug includes a spray or a liquid formulation.

[0012] Preferably, the above-mentioned cotton aphid control drug formulation includes 5% eucalyptol soluble concentrate SL and 50% flonicamid water-dispersible granules WG.

[0013] More preferably, in the above-mentioned cotton aphid control drug formulation, the volume-to-mass ratio of 5% eucalyptol soluble concentrate SL and 50% flonicamid water-dispersible granules WG is 80 mL: (0.42 g - 1 g).

[0014] More preferably, in the above-mentioned cotton aphid control drug formulation, the volume-to-mass ratio of 5% eucalyptol soluble concentrate SL and 50% flonicamid water-dispersible granules WG is 80 mL: 1 g.

[0015] The beneficial effects of this invention include: the combination of eucalyptol and flonicamid in the cotton aphid control drug composition provided by this invention at a mass ratio of (8-32):1 has a synergistic effect on the killing of cotton aphids. Specifically, the killing effect of the combination of eucalyptol and flonicamid in the above mass ratio on cotton aphids is significantly higher than that of a single agent, and it is not an additive effect. Detailed Implementation

[0016] The embodiments described are provided to better illustrate the present invention, but are not intended to limit the scope of the invention to the embodiments described. Therefore, non-essential improvements and adjustments made to the embodiments by those skilled in the art based on the above description are still within the scope of protection of the present invention.

[0017] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. Singular expressions include plural expressions unless they have a distinct meaning in the context. As used herein, it should be understood that terms such as “comprising,” “having,” “including,” are intended to indicate the presence of features, numbers, operations, components, parts, elements, materials, or combinations thereof. The terminology of the invention is disclosed in the specification and is not intended to exclude the possibility that one or more other features, numbers, operations, components, parts, elements, materials, or combinations thereof may be present or added. As used herein, “ / ” may be interpreted as “and” or “or,” depending on the context.

[0018] To better understand the present invention, specific examples are provided below to further illustrate the content of the present invention, but the content of the present invention is not limited to the examples below.

[0019] Preparation Examples

[0020] Examples 1 to 9 and Comparative Examples 1 to 2

[0021] First, the effects of eucalyptol and flonicamid on cotton aphids (cotton aphids) were determined. Aphid gossip The indoor toxicity of Glover was determined as follows: Eucalyptol and flonicamid were diluted with 0.1% (v / v) Tween 80 aqueous solution to prepare 5-7 gradient solutions. The leaf immersion method recommended by the FAO was then used for bioassay. Cotton leaves infested with aphids were immersed in different concentrations of the pesticide solution for 10 seconds, drained, and placed face down in petri dishes. After 48 hours at room temperature (25±2)℃, the number of dead aphids was checked. During the check, the insects were gently touched with a small brush; if the insects did not move at all, they were considered dead. A mortality rate <10% was considered a valid determination. A 0.1% (v / v) Tween aqueous solution was used as a control, with 30 aphids treated at each concentration in 3 replicates. The toxicity regression equation (Y=A+BX) and the median lethal concentration (LC50) were calculated using DPSv6.55 software based on the mortality probability and concentration logarithm. 50 The values ​​and 95% confidence intervals are shown in Table 1 below. The results show that the LC50 values ​​of eucalyptol and flonicamid against cotton aphids are... 50 The concentrations were 30.35 mg / L and 3.74 mg / L, respectively.

[0022] Table 1. Toxicity determination of two insecticides against cotton aphids

[0023]

[0024] Secondly, based on the above test results, LC-1 assays for eucalyptol and flonicamid were prepared separately using 0.1% (volume fraction) Tween 80 water. 50 The solutions were then mixed according to different volume ratios, and the volume ratios were converted into mass ratios. Specifically, for example, with a volume ratio of 9:1 for eucalyptol solution and flonicamid solution, the concentration of eucalyptol in the mixed solution was LC. 50 (30.35 mg / L) 9 / 10 = 27.31 mg / L, the concentration of flonicamid is its LC50. 50 (3.74 mg / L) 1 / 10 = 0.37 mg / L, so the ratio of effective ingredients is 27.31 / 0.37 = 73:1; the specific compound solutions with different volume ratios are shown in Table 2 below.

[0025] Table 2. Ratio of active ingredients of eucalyptol and flonicamid in Examples / Comparative Examples

[0026]

[0027] Performance testing

[0028] (1) Poisoning effect test

[0029] The optimal ratio was screened using an interactive assay method (Sun YP, Johnson ER, 1960. Analysis of joint action of insecticides against house flies. J. Econ. Entomol, (53): 887-891; Gao Zhiqiang et al., 2007. Indoor toxicity determination of 5% cypermethrin and 4.5% high-efficiency cypermethrin EC mixture against diamondback moth. Pesticides, 46 (5): 353-354). The above-mentioned compound insecticides (Examples 1 to 9) and single-agent treatments (Comparative Example 1 and Comparative Example 2) were used to treat cotton aphids, and the mortality rate was measured. The toxicity-efficacy ratio analysis was used to evaluate the toxicity of each insecticide against the tested pests. Among them, a toxicity-efficacy ratio >1.25 indicates a synergistic effect, a toxicity-efficacy ratio <0.75 indicates an antagonistic effect, and a toxicity-efficacy ratio of 0.75 to 1.25 indicates an additive effect (refer to the literature "Lü Guizhen et al., Screening of the optimal ratio of chlorfenapyr, indoxacarb and flufenoxuron for the control efficacy of diamondback moth. Acta Entomologica Sinica, 2011, 48(2): 306-312." and "Su Xu et al., Combined toxicity of abamectin and four biological insecticides against wheat aphid. Journal of Triticeae Crops, 2020, 40(5): 630-637").

[0030] Toxicity-efficacy ratio = Actual mortality rate / Expected mortality rate;

[0031] Expected mortality rate = MR A ×P A +MR B ×P B ;

[0032] Among them, MR A The LC of the tested pests in pesticide A 50 The actual mortality rate, P A Represents the volume percentage of pesticide A; MR B The LC of pesticide B represents the tested pests. 50 The actual mortality rate, P B This represents the volume percentage of pesticide B.

[0033] The test results are shown in Table 3. When the volume ratios of eucalyptol and flonicamid were 8:2, 7:3, 6:4, and 5:5 (with active ingredient mass ratios of 32:1, 19:1, 12:1, and 8:1, respectively), the toxicity-to-efficacy ratios were 1.31, 1.39, 1.31, and 1.36, respectively, all greater than 1.25, indicating a synergistic effect. The toxicity-to-efficacy ratios for the other five volume ratios ranged from 0.75 to 1.25, indicating an additive effect.

[0034] Table 3. Killing effect of pesticides used in examples / comparative studies on cotton aphids.

[0035]

[0036] (2) Determination of the synergistic effect of the mixture in the examples

[0037] Examples of the best combinations of proportions and synergistic effects determined in (1) above (Examples 2, 3, 4, and 5) were further tested for toxicity synergistic effects using the same method as the toxicity test in (1) above. The co-toxicity coefficient (CTC) of each mixture was calculated using the Sun Yunpei method, and the calculation formula is as follows:

[0038] Test reagent toxicity index (TI) = (Standard reagent LC) 50 Value / LC of the test reagent 50 Value) × 100;

[0039] Actual Toxicity Index (ATI) of Mixture = (LC50 of Standard Reagent) 50 Value / LC of Mixture 50 Value) × 100;

[0040] Theoretical Toxicity Index (TTI) of a Mixture = TI(A) × Percentage of Agent A in the Mixture + TI(B) × Percentage of Agent B in the Mixture;

[0041] Co-toxicity coefficient (CTC) = [Actual toxicity index (ATI) of mixture / Theoretical toxicity index (TTI) of mixture] × 100;

[0042] A co-toxicity coefficient of 80–120 indicates an additive effect, a co-toxicity coefficient ≥120 indicates a synergistic effect, and a co-toxicity coefficient ≤80 indicates an antagonistic effect.

[0043] The test results are shown in Table 4 below. The results show that when eucalyptol and flonicamid are compounded in ratios of 32:1, 19:1, 12:1, and 8:1, the co-toxicity coefficient (CTC) is greater than 120, indicating a synergistic effect. Among them, the synergistic effect is most obvious when eucalyptol and flonicamid are in a ratio of 8:1, with a CTC of 827. The synergistic effect is second best when eucalyptol and flonicamid are in a ratio of 12:1, with a CTC of 445. According to the cross-test method and the CTC method, the synergistic effect of eucalyptol and flonicamid is the highest when eucalyptol and flonicamid are in a ratio of 8:1, which is the optimal mixing ratio.

[0044] Table 4. Co-toxicity of eucalyptol and flonicamid at different mixing ratios against cotton aphids.

[0045]

[0046] (3) Field efficacy test

[0047] In the following tests, the eucalyptol agent was 5% eucalyptol soluble concentrate SL (Beijing Yage Nong Biopharmaceutical Co., Ltd.); the flonicamid agent was 50% flonicamid water-dispersible granules WG (Corteva Agriscience Co., Ltd.).

[0048] (3-1) The test crop was cotton, and the test target was cotton seedling aphids. The field trial was conducted on May 26, 2025, during the peak occurrence of cotton aphids, with each plot being approximately 20m². 2 Each treatment was randomly assigned, with a water treatment serving as a blank control. Each treatment group was replicated four times. Five sampling points were taken from each plot, and the number of aphids on three consecutive cotton plants was investigated at each point. The number of live aphids was investigated before application and at 1, 3, and 7 days after application (application details are shown in Table 6 below). The aphid population reduction rate and control efficacy were calculated.

[0049] Insect population reduction rate (%) = (Insect population before pesticide application - Insect population after pesticide application) / Insect population before pesticide application × 100%;

[0050] Control efficacy (%) = (Pest population reduction rate in the treated area - Pest population reduction rate in the control area) / (1 - Pest population reduction rate in the control area) × 100%;

[0051] (3-2) Statistical analysis was performed using SPSS 20.0 software, and the control effects of each treatment were statistically analyzed using Duncan's new multiple range method.

[0052] The test results are shown in Table 5 below. According to Table 4 above, the synergistic effect is better when the effective mass ratio of eucalyptol to flonicamid is 8:1, 12:1, and 19:1. Within the recommended field dosage range, the dosages of 5% eucalyptol soluble concentrate SL and 50% flonicamid water-dispersible granules WG, calculated based on the effective ingredient mass ratio, are 40 mL and 0.5 g, 40 mL and 0.33 g, and 40 mL and 0.21 g, respectively.

[0053] Table 5. Field control efficacy of eucalyptol and flonicamid mixtures against cotton aphids.

[0054]

[0055] Table 5 above shows that there are significant differences in the control efficacy of mixed and single-agent treatments against cotton aphids. Specifically, 1 day after application, the control efficacy of the mixture of eucalyptol and flonicamid against cotton aphids was 27.36%-32.86%, which was not significantly different from the 50% flonicamid WG treatment, but significantly higher than the 5% eucalyptol SL treatment. At 3 and 7 days after application, the control efficacy of the mixture of eucalyptol and flonicamid against cotton aphids was 74.52%-83.46% and 87.79%-96.18%, respectively, both significantly higher than the control efficacy of either flonicamid or eucalyptol alone. Furthermore, when the two agents were mixed, the highest control efficacy was achieved when the mass ratio of eucalyptol to flonicamid was 8:1, followed by 12:1 and 19:1, consistent with the results of the indoor toxicity ratio screening. The results showed that the combination of eucalyptol and flonicamid had a significant synergistic effect, with the optimal mass ratio being 8:1.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A drug composition for controlling cotton aphids, characterized in that, It is composed of eucalyptol and flonicamid, with a mass ratio of eucalyptol to flonicamid of 8:

1.

2. A pesticide formulation for controlling cotton aphids, characterized in that, The cotton aphid control drug composition according to claim 1.

3. The cotton aphid control agent according to claim 2, characterized in that, The pesticide formulations for controlling cotton aphids include 5% eucalyptol soluble concentrate SL and 50% flonicamid water-dispersible granules WG.

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