Plant-derived compound insecticide for preventing and treating armyworm and preparation method thereof

Abstract

The present application belongs to the technical field of biological pesticides, and provides a plant source compound insecticide for preventing and treating armyworms and a preparation method thereof. The insecticide is prepared from raw materials including the following components by weight fraction: 0.9-1.1 parts of n-butanol phase extract of soapberry, 0.9-1.1 parts of ethyl acetate phase extract of trema orientalis, 0.9-1.1 parts of chloroform phase extract of cyrtomium fortunei, 99-101 parts of cosolvent, and 896-897 parts of deionized water. The insecticide is extracted from soapberry, trema orientalis and cyrtomium fortunei, and has a good toxic effect on armyworms. The raw materials of the insecticide are abundant and low in cost. Meanwhile, the insecticide is high in efficiency, non-toxic, non-polluting and less likely to cause pesticide resistance of pests, and is conducive to maintaining ecological balance and conforms to the development concept of converting traditional organic chemical pesticides into environmentally friendly pesticides.

Description

Technical Field

[0001] This invention belongs to the field of biological pesticide technology, specifically relating to a plant-derived compound insecticide for controlling armyworms and its preparation method. Background Technology

[0002] Armyworm (Mythimna separata), belonging to the family Noctuidae in the order Lepidoptera, is a polyphagous pest with strong pesticide resistance, damaging gramineous crops such as wheat, corn, and sorghum. It can completely defoliate crops, break off ears of wheat and millet, and reduce yields, causing severe damage and becoming a major agricultural pest nationwide. Simultaneously, due to the serious problems caused by the widespread use of chemical pesticides, such as environmental pollution and increased pesticide resistance in pests, the development of plant-derived pesticides has become increasingly important.

[0003] There are nearly 500,000 plant species in the world, but only a small percentage have had their chemical composition studied, and the structural characteristics of most remain unclear. These plants will undoubtedly become a major force in the pesticide market. Therefore, providing a plant-derived compound insecticide for controlling armyworms is urgently needed. Plant-derived insecticides are easily degradable, readily available, and simple to prepare. They do not accumulate in the food chain, pose no harm to higher animals or natural enemies of pests, and are unlikely to cause environmental pollution. Therefore, developing environmentally friendly plant-derived insecticides is of great significance for ecological protection and agricultural economic development.

[0004] Currently available plant-derived insecticides suffer from problems such as limited ingredients, poor control efficacy, and short duration of action, making them difficult to widely promote in practical applications. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a plant-derived compound insecticide for controlling armyworms and its preparation method. This insecticide extracts and separates the insecticidal active ingredients from crude ethanol extracts of different biological materials, and then compoundes them in a certain proportion. By utilizing the complementary advantages of the insecticidal mechanisms of different medicinal active ingredients, the insecticidal effect of killing armyworms is improved, achieving a synergistic effect.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: On the one hand, the present invention provides a plant-derived compound insecticide for controlling armyworms, which is prepared by weight from raw materials containing the following components: 0.9-1.1 parts of Sapindus mukorossi n-butanol phase extract, 0.9-1.1 parts of Rosa trifoliata ethyl acetate phase extract, 0.9-1.1 parts of Dryopteris crassirhizoma chloroform phase extract, 99-101 parts of cosolvent, and 896-897 parts of deionized water.

[0007] Preferably, the co-solvent is Tween 80.

[0008] Preferably, the mass ratio of the Sapindus mukorossi n-butanol extract, the Rotenone trifoliata ethyl acetate extract, and the Dryopteris crassirhizoma chloroform extract is 1:1:1.

[0009] On the other hand, the present invention provides a method for preparing a plant-derived compound insecticide for controlling armyworms, comprising the following steps: compounding the n-butanol phase extract of Sapindus mukorossi, the ethyl acetate phase extract of Rosa trifoliata, the chloroform phase extract of Dryopteris crassirhizoma, a solubilizer, and deionized water in a certain proportion to obtain the plant-derived compound insecticide.

[0010] Preferably, the method for preparing the Sapindus mukorossi n-butanol phase extract includes the following steps:

[0011] (1) Dissolution: The ethanol extract of Sapindus mukorossi was dissolved in deionized water to obtain the ethanol extract of Sapindus mukorossi, with a mass-to-volume ratio of 1:5 (g / ml);

[0012] (2) Extraction: Extract the Sapindus mukorossi ethanol extract with an equal volume of extractant n-butanol for 3-5 min, and combine the extracts 3-5 times to obtain the Sapindus mukorossi n-butanol extract.

[0013] (3) Concentration: The n-butanol extract of Sapindus mukorossi was concentrated under reduced pressure at 45-60℃ on a rotary evaporator to obtain a paste-like extract.

[0014] (4) Drying: The paste-like extract was dried in an oven at 40°C to obtain the n-butanol phase extract of Sapindus mukorossi.

[0015] The preparation method of the Sapindus mukorossi ethanol extract includes the following steps:

[0016] (1) Powdering: Take mature Sapindus mukorossi fruits, dry them, peel them, and crush them. Pass them through a 60-mesh sieve to obtain powder.

[0017] (2) Extraction: Weigh the powder into an ethanol aqueous solution with a volume fraction of (80%-95%), with a material-to-liquid ratio of 1:10 (g / ml);

[0018] (3) Extraction: Perform ultrasonic-assisted extraction three times under the following conditions: room temperature, ultrasonic power 20w, extraction time 50min, combine the extracts, and filter under reduced pressure to remove impurities;

[0019] (4) Concentration: The filtered extract is added to a rotary evaporator and concentrated under reduced pressure at 45-60℃ to obtain a paste-like extract.

[0020] (5) Drying: The extract was dried in an oven at 40°C to obtain the Sapindus mukorossi ethanol extract.

[0021] Preferably, the method for preparing the ethyl acetate extract of rotenone includes the following steps:

[0022] (1) Dissolution: The ethanol extract of *Rotenoptera trifoliata* was dissolved in deionized water to obtain the ethanol extract of *Rotenoptera trifoliata*, with a mass-to-volume ratio of 1:5 (g / ml);

[0023] (2) Extraction: Extract the ethanol extract of *Rotenoptera trifoliata* with an equal volume of ethyl acetate extractant for 3-5 min. Combine the extracts after 3-5 extractions to obtain the ethyl acetate extract of *Rotenoptera trifoliata*.

[0024] (3) Concentration: The ethyl acetate extract of rotenone was concentrated under reduced pressure at 45-60℃ on a rotary evaporator to obtain a paste-like extract.

[0025] (4) Drying: The paste-like extract was dried in an oven at 40°C to obtain the ethyl acetate phase extract of rotenone.

[0026] The preparation method of the ethanol extract of *Rotenoptera trifoliata* includes the following steps:

[0027] (1) Pulverization: Take the whole plant of *Derris trifoliata*, dry it, pulverize it, and pass it through a 60-mesh sieve to obtain powder;

[0028] (2) Extraction: Weigh the powder into an ethanol aqueous solution with a volume fraction of (80%-95%), with a material-to-liquid ratio of 1:10 (g / ml);

[0029] (3) Extraction: Perform ultrasonic-assisted extraction three times under the following conditions: room temperature, ultrasonic power 20w, extraction time 50min, combine the extracts, and filter under reduced pressure to remove impurities;

[0030] (4) Concentration: The filtered extract is added to a rotary evaporator and concentrated under reduced pressure at 45-60℃ to obtain a paste-like extract.

[0031] (5) Drying: The extract was dried in an oven at 40°C to obtain the ethanol extract of rotenone.

[0032] Preferably, the method for preparing the chloroform phase extract of Dryopteris crassirhizoma includes the following steps:

[0033] (1) Dissolution: The ethanol extract of Dryopteris crassirhizoma was dissolved in deionized water to obtain the ethanol extract of Dryopteris crassirhizoma, with a mass-to-volume ratio of 1:5 (g / ml).

[0034] (2) Extraction: Extract the ethanol extract of Dryopteris crassirhizoma with an equal volume of chloroform extractant for 3-5 min, and combine the extracts 3-5 times to obtain the chloroform extract of Dryopteris crassirhizoma.

[0035] (3) Concentration: The chloroform extract of Dryopteris crassirhizoma was concentrated under reduced pressure at 45-60℃ on a rotary evaporator to obtain a paste-like extract.

[0036] (4) Drying: The paste-like extract was dried in an oven at 40°C to obtain the chloroform phase extract of Dryopteris crassirhizoma.

[0037] The preparation method of the Dryopteris crassirhizoma ethanol extract includes the following steps:

[0038] (1) Crushing: Take the above-ground parts of Dryopteris crassirhizoma, dry them, crush them, and pass them through a 60-mesh sieve to obtain powder;

[0039] (2) Extraction: Weigh the powder into an ethanol aqueous solution with a volume fraction of (80%-95%), with a material-to-liquid ratio of 1:10 (g / ml);

[0040] (3) Extraction: Perform ultrasonic-assisted extraction three times under the following conditions: room temperature, ultrasonic power 20w, extraction time 50min, combine the extracts, and filter under reduced pressure to remove impurities;

[0041] (4) Concentration: The filtered extract is added to a rotary evaporator and concentrated under reduced pressure at 45-60℃ to obtain a paste-like extract.

[0042] (5) Drying: The extract was dried in an oven at 40°C to obtain the Dryopteris crassirhizoma ethanol extract.

[0043] In this invention, the soapberry (Sapindus mukorossi), also known as the soap tree, is mainly grown in Southeast Asian countries and the Yangtze River basin in my country, distributed in areas south of the Huai River. The pericarp of the soapberry contains a large number of medicinally active ingredients, mainly including triterpenoid saponins, sesquiterpenoid glycosides, and volatile oils.

[0044] This invention first uses ethanol to extract the soapberry peel powder, and then uses n-butanol to extract the soapberry ethanol extract, which can fully extract the active ingredients such as triterpenoid saponins inside.

[0045] *Derris trifoliata*, also known as water vine, poison vine, and three-leaf poison vine, mainly grows in tropical and subtropical regions of Asia. In my country, its distribution is concentrated in Guangdong, Guangxi, and Hainan provinces. The roots, stems, and leaves of *Derris trifoliata* are all poisonous, and it is mostly used in traditional medicine, commonly as a fishing bait or insecticide. The medicinal active ingredients of *Derris* species are mainly flavonoids, isoflavones, and rotenone, which are easily soluble in ethyl acetate extracts and have strong antifeedant activity against adult and larval aphids and other pests.

[0046] This invention first uses ethanol to extract rotenone powder, and then uses ethyl acetate to extract the ethanol extract of rotenone, which can fully extract its active ingredients such as rotenone.

[0047] Dryopteris crassirhizoma, also known as Guanzhong, is a perennial fern. Its rhizome and petiole remnants are used medicinally for their heat-clearing, detoxifying, hemostatic, and insecticidal properties. The plant contains four alkaloids and eight flavonoids, and after chloroform soaking and filtration, it exhibits good insecticidal activity.

[0048] This invention first uses ethanol to extract the powdered stems and leaves of Dryopteris crassirhizoma, and then uses chloroform to extract the ethanol extract of Dryopteris crassirhizoma, which can fully extract the active ingredients such as alkaloids inside.

[0049] The toxic mechanism of alkaloids on herbivorous insects mainly manifests in the desensitization inhibition of acetylcholine receptors in their cells, interfering with the stimulation transmission of the insect's nervous system, thereby causing nerve paralysis and death. Saponins can attack the insect's detoxification metabolism, causing toxic substances to continuously act on the insect's body, disrupting the insect's normal physiological and biochemical processes, and ultimately leading to death. Flavonoids mainly interfere with the insect's normal respiration, inhibiting the electron transport chain in the insect's cells, gradually reducing ATP levels, leading to insufficient energy supply, and exhibiting symptoms such as sluggish movement and nerve paralysis, ultimately resulting in slow death.

[0050] The active ingredients in these three medicinal plants have different effects and mechanisms of action against pests. Sapindus mukorossi saponins and aglycones have strong surface activity, are neutral, readily biodegradable, and non-toxic to the skin. The inventors have creatively discovered that when the active ingredients alkaloids, flavonoids, and saponins from these three medicinal plants are mixed, the saponins can uniformly mix the alkaloids and flavonoids, forming a cross-linked system. This results in a mixture of three active ingredients that is not only stable but also synergistic, simultaneously producing a powerful killing effect on pests from different angles, preventing the development of pesticide resistance. It exhibits biological activities such as toxicity, repellency, antifeedant effects, and inhibition of oviposition and growth in harmful insects. Furthermore, the natural active ingredients are readily and rapidly degraded in the natural environment, leaving no residue.

[0051] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0052] This invention provides a plant-derived compound insecticide for controlling armyworms. It extracts effective medicinal components from Sapindus mukorossi, Derris trifoliata, and Dryopteris crassirhizoma, and then combines them to form an insecticide that exhibits good toxicity against armyworms. The raw materials are abundant and inexpensive. Furthermore, this compound insecticide has advantages such as high efficiency, non-toxicity, no pollution, and low likelihood of inducing pesticide resistance in pests, thus contributing to maintaining ecological balance and aligning with the development concept of transitioning from traditional organic chemical pesticides to environmentally friendly pesticides. Detailed Implementation

[0053] The present invention will now be described in further detail with reference to specific embodiments, so that those skilled in the art can more clearly understand the present invention.

[0054] The specific implementation method is as follows:

[0055] Example 1

[0056] The following preparation methods were employed: ethyl acetate phase extract, n-butanol phase extract, and chloroform phase extract of Sapindus mukorossi. The specific preparation process is as follows:

[0057] Prepare three portions of Sapindus mukorossi ethanol extract

[0058] (1) Powdering: Take mature Sapindus mukorossi fruits, dry them, peel them, and crush them. Pass them through a 60-mesh sieve to obtain powder.

[0059] (2) Extraction: Weigh 100g of powder into three portions and extract them separately in a 90% ethanol aqueous solution with a material-to-liquid ratio of 1:10 (g / ml);

[0060] (3) Extraction: Three portions of ethanol aqueous solution were each subjected to ultrasonic-assisted extraction three times under the following conditions: 35℃, ultrasonic power 20w, extraction time 50min. The three extracts were combined and filtered under reduced pressure to remove impurities and obtain three extracts.

[0061] (4) Concentration: Add the three extracts to a rotary evaporator and concentrate them under reduced pressure at 50-55℃ to obtain a paste-like extract.

[0062] (5) Drying: The three portions of the extract were dried in an oven at 40°C to obtain three portions of Sapindus mukorossi ethanol extract, with a weight of (12.48±0.96)g. The yield of Sapindus mukorossi ethanol extract was calculated to be (12.48±0.96)%.

[0063] Preparation of phase extracts of Sapindus mukorossi

[0064] 1) Dissolution: Dissolve the three portions of Sapindus mukorossi ethanol extract obtained in the above steps in deionized water to obtain three portions of Sapindus mukorossi ethanol extract solution. Stir magnetically to promote dissolution. The mass-volume ratio is 1:5 (g / ml).

[0065] 2) Extraction: Take equal volumes of extractants ethyl acetate, n-butanol, and chloroform and extract each of the three portions of Sapindus mukorossi ethanol extract three times, for 3-5 minutes each time, and collect the ethyl acetate extract, n-butanol extract, and chloroform extract of Sapindus mukorossi respectively.

[0066] 3) Concentration: The ethyl acetate extract of Sapindus mukorossi was concentrated twice under reduced pressure at 45°C, the n-butanol extract of Sapindus mukorossi was concentrated under reduced pressure at 60°C, and the chloroform extract of Sapindus mukorossi was concentrated under reduced pressure at 50°C to obtain extracts in the form of pastes.

[0067] 4) Drying: The extracts were dried in an oven at 40°C. The mass of the ethyl acetate phase extract of Sapindus mukorossi was (1.22±0.06) g, the mass of the n-butanol phase extract of Sapindus mukorossi was (1.82±0.14) g, and the mass of the chloroform phase extract of Sapindus mukorossi was (1.04±0.15) g.

[0068] Example 2

[0069] Prepare ethyl acetate phase extract, n-butanol phase extract, and chloroform phase extract of rotenone. The specific preparation process is as follows:

[0070] Preparation of three portions of ethanol extract of rotenone

[0071] Weigh out 100g of dried *Derris trifoliata* powder, extract with ethanol, concentrate and dry to obtain (13.07±0.53)g of *Derris trifoliata* ethanol extract. The specific preparation method is the same as that in Example 1 for "preparing three parts of *Sapindus mukorossi* ethanol extract", except that "mature *Sapindus mukorossi* fruit" is replaced with "whole *Derris trifoliata* plant". This process will not be described in detail.

[0072] Preparation of phase extracts of rotenone

[0073] The three portions of *Robinia pseudoacacia* ethanol extract obtained in the above steps were extracted with ethyl acetate to obtain (2.03±0.15) g of *Robinia pseudoacacia* ethyl acetate phase extract, (1.83±0.09) g of *Robinia pseudoacacia* n-butanol phase extract, and (1.43±0.10) g of *Robinia pseudoacacia* chloroform phase extract. The specific extraction method is the same as that used in Example 1 for "Preparation of *Sapindus mukorossi* Phase Extracts," except that the "*Sapindus mukorossi* ethanol extract" in the raw materials is replaced with "*Robinia pseudoacacia* ethanol extract." This process will not be described in detail further.

[0074] Example 3

[0075] The ethyl acetate phase extract, n-butanol phase extract, and chloroform phase extract of *Dryopteris crassirhizoma* were prepared. The specific preparation process is as follows:

[0076] Prepare three portions of Dryopteris crassirhizoma ethanol extract:

[0077] Weigh out 100g of dried Dryopteris crassirhizoma powder, extract with ethanol, concentrate and dry to obtain three portions of Dryopteris crassirhizoma ethanol extract (10.09±0.72)g. The specific preparation method is the same as the preparation method of "preparing three portions of Sapindus mukorossi ethanol extract" in Example 1, except that "mature Sapindus mukorossi fruit" in the raw materials is replaced with "the aerial parts of Dryopteris crassirhizoma". This process will not be described in detail.

[0078] Preparation of various phase extracts of Dryopteris crassirhizoma:

[0079] The three portions of *Dryopteris crassirhizoma* ethanol extract obtained in the above steps were extracted with ethyl acetate to obtain (1.09±0.09) g of *Dryopteris crassirhizoma* ethyl acetate phase extract, (0.97±0.02) g of *Dryopteris crassirhizoma* n-butanol phase extract, and (1.45±0.11) g of *Dryopteris crassirhizoma* chloroform phase extract. The specific extraction method is the same as that in Example 1, “Preparation of the various phase extracts of *Sapindus mukorossi*”, except that the “*Sapindus mukorossi* ethanol extract” in the raw materials is replaced with the “*Dryopteris crassirhizoma* ethanol extract”. This process will not be described in detail further.

[0080] Experimental Example 1

[0081] The indoor toxicity of the ethyl acetate phase extract, n-butanol phase extract, and chloroform phase extract of Sapindus mukorossi obtained in Example 1 for controlling armyworm was tested. A 10% Tween 80 aqueous solution was used as a blank control.

[0082] Fresh corn leaves were punched into discs about 1 cm in diameter. The discs were then immersed in solutions of ethyl acetate extract, n-butanol extract, and chloroform extract of Sapindus mukorossi for 2-3 seconds, and air-dried. Thirty third-instar larvae that had been starved for 4 hours were placed on the corn leaves for toxicity testing.

[0083] Repeat three times. Record larval mortality at 24h, 48h, and 72h, and calculate the corrected mortality rate using the formula. The results are shown in Table 1.

[0084] The calculation formula is as follows: Mortality rate = (Number of dead insects / Total number of insects) × 100%

[0085] Corrected mortality rate = [(treatment mortality rate - control mortality rate) / (1 - control mortality rate)] × 100%

[0086] Table 1. Toxicity of Sapindus mukorossi extracts against armyworms.

[0087]

[0088] As shown in Table 1, the insecticides formulated with different extracts of Sapindus mukorossi in the embodiments of the present invention all exhibited varying degrees of control effects on the third instar larvae of armyworms. Compared with the control group, the n-butanol extract of Sapindus mukorossi showed the best insecticidal effect, with corrected mortality rates exceeding 50% at different time points. This suggests that the main medicinal insecticidal component of Sapindus mukorossi, saponins, is primarily dissolved in the n-butanol phase.

[0089] Experimental Example 2

[0090] The indoor toxicity of the ethyl acetate phase extract, n-butanol phase extract, and chloroform phase extract of *Rotenoptera trifoliata* obtained in Example 2 for controlling armyworm was tested. A 10% Tween 80 aqueous solution was used as a blank control.

[0091] Fresh corn leaves were punched into discs about 1 cm in diameter. The discs were then immersed in solutions of ethyl acetate, n-butanol, and chloroform extracts of rotenone for 2-3 seconds, and air-dried. Thirty third-instar larvae that had been starved for 4 hours were placed on the corn leaves for toxicity testing.

[0092] Repeat three times. Record larval mortality at 24h, 48h, and 72h, and calculate the corrected mortality rate using the formula. The results are shown in Table 2.

[0093] Table 2. Toxicity of different phase extracts of *Rhizophora trifoliata* against armyworms.

[0094]

[0095] As shown in Table 2, compared with the control group, the insecticide prepared by ethanol extraction and ethyl acetate extraction of *Derris trifoliata* was the most effective, with corrected mortality rates of over 60% at different time periods. This suggests that the flavonoids, the medicinal insecticidal components in *Derris trifoliata*, are mainly dissolved in the n-butanol phase.

[0096] Experimental Example 3

[0097] The indoor toxicity of the ethyl acetate phase extract, n-butanol phase extract, and chloroform phase extract of *Dryopteris crassirhizoma* obtained in Example 3 for controlling armyworm was tested. A 10% Tween 80 aqueous solution was used as a blank control.

[0098] Fresh corn leaves were punched into discs about 1 cm in diameter. The discs were then immersed in solutions of ethyl acetate, n-butanol, and chloroform extracts of Dryopteris crassirhizoma for 2-3 seconds, and air-dried. Thirty third-instar larvae that had been starved for 4 hours were placed on the corn leaves for toxicity testing.

[0099] Repeat three times. Record larval mortality at 24h, 48h, and 72h, and calculate the corrected mortality rate using the formula. The results are shown in Table 3.

[0100] Table 3. Toxicity of various extracts of Dryopteris crassirhizoma against armyworms.

[0101]

[0102]

[0103] As shown in Table 3, compared with the control group, the insecticide prepared by extracting Dryopteris crassirhizoma with ethanol and then with n-butanol had a corrected mortality rate of over 45% at different time points. The insecticidal effect of other extraction phases was poor. Therefore, it can be inferred that the alkaloids, the medicinal insecticidal components in Dryopteris crassirhizoma, are mainly dissolved in the chloroform phase of the extractant.

[0104] Example 4

[0105] Preparation of ethyl acetate phase compound insecticides:

[0106] The ethyl acetate extracts of Sapindus mukorossi from Example 1, Rotenoptera trifoliata from Example 2, and Dryoptera fructus from Example 3 were dissolved in a 10% (v / v) Tween 80 aqueous solution at a mass ratio of 1:1:1 to prepare an ethyl acetate compound insecticide with an insecticide concentration of 3 g / L. Specifically, 1 L of the ethyl acetate compound insecticide contains 1.0 g of Sapindus mukorossi ethyl acetate extract, 1.0 g of Rotenoptera trifoliata ethyl acetate extract, 1.0 g of Dryoptera fructus ethyl acetate extract, 100 mL of Tween 80, and the remainder is deionized water.

[0107] Example 5

[0108] Preparation of n-butanol-based compound insecticides:

[0109] The n-butanol extracts of Sapindus mukorossi from Example 1, the n-butanol extracts of Rosa trifoliata from Example 2, and the n-butanol extracts of Dryopteris crassirhizoma from Example 3 were dissolved in a 10% (v / v) Tween 80 aqueous solution at a mass ratio of 1:1:1 to prepare a n-butanol-based compound insecticide with an insecticide concentration of 3 g / L. Specifically, 1 L of the n-butanol-based compound insecticide contains 1.0 g of Sapindus mukorossi n-butanol extract, 1.0 g of Rosa trifoliata n-butanol extract, 1.0 g of Dryopteris crassirhizoma n-butanol extract, 100 mL of Tween 80, and the remainder is deionized water.

[0110] Example 6

[0111] Preparation of chloroform-phase compound insecticides:

[0112] The chloroform extracts of Sapindus mukorossi from Example 1, Rotenoptera trifoliata from Example 2, and Dryoptera fructus from Example 3 were dissolved in a 10% (v / v) Tween 80 aqueous solution at a mass ratio of 1:1:1 to prepare a chloroform-phase compound insecticide with an insecticide concentration of 3 g / L. Specifically, 1 L of the chloroform-phase compound insecticide contains 1.0 g of Sapindus mukorossi chloroform extract, 1.0 g of Rotenoptera trifoliata chloroform extract, 1.0 g of Dryoptera fructus chloroform extract, 100 mL of Tween 80, and the remainder is deionized water.

[0113] Example 7

[0114] Preparation of mixed-phase compound insecticides:

[0115] The *Sapindus mukorossi* n-butanol extract from Example 1, the *Rotenone trifoliata* ethyl acetate extract from Example 2, and the *Dryopteris crassirhizoma* chloroform extract from Example 3 were dissolved in a 10% (v / v) Tween 80 aqueous solution at a mass ratio of 1:1:1 to prepare a mixed-phase compound insecticide with an insecticide concentration of 3 g / L. Specifically, 1 L of the chloroform-phase compound insecticide contains 1.0 g of *Sapindus mukorossi* n-butanol extract, 1.0 g of *Rotenone trifoliata* ethyl acetate extract, 1.0 g of *Dryopteris crassirhizoma* chloroform extract, 100 mL of Tween 80, and the remainder being deionized water.

[0116] Example 8

[0117] The mixed-phase compound insecticide in Example 7 was diluted, and Tween 80 and deionized water were added in proportion to make the insecticide concentration 1.5 g / L.

[0118] Example 9

[0119] The mixed-phase compound insecticide in Example 7 was diluted, and Tween 80 and deionized water were added in proportion to make the insecticide concentration 0.75 g / L.

[0120] Test Example 4

[0121] The six insecticides obtained in Examples 4-9 were tested for their indoor toxicity in controlling armyworms. A 10% Tween 80 aqueous solution was used as a blank control.

[0122] Fresh corn leaves were punched into round pieces about 1 cm in diameter. The pieces were then immersed in the solutions of six different insecticides for 2-3 seconds and allowed to air dry. Thirty third-instar larvae that had been starved for 4 hours were placed on the corn leaves for toxicity testing.

[0123] Repeat three times. Record larval mortality at 24h, 48h, and 72h, and calculate the corrected mortality rate using the formula. The results are shown in Table 4.

[0124] Table 4. Insecticidal activity of six compound insecticides against armyworms.

[0125]

[0126] As shown in Table 4, compared with the control group, the insecticides prepared in different ways in the embodiments of the present invention all had a certain control effect on the third instar larvae of armyworms. Among them, within 72 hours, the mixed-phase compound insecticide prepared in Example 7 of the present invention, at a concentration of 3 g / L, achieved a toxicity rate of 89.9% against the third instar larvae of armyworms. As the dilution factor increased, the mortality rate gradually decreased, but it still maintained high activity at a concentration of 0.75 g / L.

[0127] The corrected mortality rates of the three insecticides prepared in Examples 4-6 were between 40% and 60%, which were higher than those of the control group but significantly lower than those of the mixed-phase compound insecticide. This indicates that the amount of medicinal active ingredients extracted by a single extractant is relatively small, and the main insecticidal components contained in different plants are different.

[0128] Example 10

[0129] A plant-derived compound insecticide was prepared by taking the n-butanol phase extract of Sapindus mukorossi from Example 1, the ethyl acetate phase extract of Rosa trifoliata from Example 2, and the chloroform phase extract of Dryopteris crassirhizoma from Example 3.

[0130] This insecticide contains the following components: 0.9g of Sapindus mukorossi n-butanol extract, 0.9g of Rosa trifoliata ethyl acetate extract, 0.9g of Dryopteris crassirhizoma chloroform extract, 99g of Tween 80, and 896g of deionized water.

[0131] Example 11

[0132] A plant-derived compound insecticide was prepared by taking the n-butanol phase extract of Sapindus mukorossi from Example 1, the ethyl acetate phase extract of Rosa trifoliata from Example 2, and the chloroform phase extract of Dryopteris crassirhizoma from Example 3.

[0133] This insecticide contains the following components: 1.1g of Sapindus mukorossi n-butanol phase extract, 1.1g of Rosa trifoliata ethyl acetate phase extract, 1.1g of Dryopteris crassirhizoma chloroform phase extract, 101g of Tween 80, and 897g of deionized water.

[0134] Experimental Example 5

[0135] The three compound insecticides obtained in Examples 7, 10, and 11 were tested for their indoor toxicity in controlling armyworms. A 10% Tween 80 aqueous solution was used as a blank control.

[0136] Take fresh corn leaves and punch them into round pieces about 1 cm in diameter. Dip them in the solutions of three compound insecticides for 2-3 seconds and let them air dry. Place 30 third-instar larvae that have been starved for 4 hours on the corn leaves for toxicity testing.

[0137] Repeat three times. Record larval mortality at 24h, 48h, and 72h, and calculate the corrected mortality rate using the formula. The results are shown in Table 5.

[0138] Table 5. Insecticidal activity of three compound insecticides against armyworms.

[0139]

[0140] As shown in Table 5, the insecticide prepared by combining the n-butanol phase extract of Sapindus mukorossi, the ethyl acetate phase extract of Rosa trifoliata, and the chloroform phase extract of Dryopteris crassirhizoma exhibits stable and excellent effects. This indicates that the mixture of the three active ingredients in the embodiments of the present invention is not only stable in composition, but also has a synergistic effect with each other, which can simultaneously produce a great killing effect on pests from different aspects, making it impossible for pests to develop resistance.

[0141] In summary, the mixed-phase insecticide provided in this embodiment of the invention has abundant and inexpensive raw material sources. This compound insecticide has advantages such as high efficiency, non-toxicity, no pollution, and low likelihood of pests developing resistance, which is beneficial for maintaining ecological balance and aligns with the development concept of transforming from traditional organic chemical pesticides to environmentally friendly pesticides.

[0142] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A plant-derived compound insecticide for controlling armyworms, characterized in that, By weight, it is prepared from raw materials containing the following components: 0.9-1.1 parts of Sapindus mukorossi n-butanol phase extract, 0.9-1.1 parts of Rosa trifoliata ethyl acetate phase extract, 0.9-1.1 parts of Dryopteris crassirhizoma chloroform phase extract, 99-101 parts of cosolvent, and 896-897 parts of deionized water. The soapberry n-butanol phase extract is obtained by extracting soapberry pericarp powder with ethanol and then extracting the soapberry ethanol extract with n-butanol. The ethyl acetate extract of *Rotenoptera trifoliata* was obtained by ethanol extraction of *Rotenoptera trifoliata* powder, followed by ethyl acetate extraction of the ethanol extract of *Rotenoptera trifoliata*. The chloroform extract of Dryopteris crassirhizoma was obtained by ethanol extraction of Dryopteris crassirhizoma stem and leaf powder, followed by chloroform extraction of the ethanol extract.

2. The plant-derived compound insecticide for controlling armyworms according to claim 1, characterized in that, The co-solvent is Tween 80.

3. The plant-derived compound insecticide for controlling armyworms according to claim 1, characterized in that, The mass ratio of the *Sapindus mukorossi* n-butanol extract, the *Rotenone trifoliata* ethyl acetate extract, and the *Dryopteris crassirhizoma* chloroform extract is 1:1:

1.

4. The method for preparing the plant-derived compound insecticide for controlling armyworms according to any one of claims 1-3, characterized in that, Includes the following steps: A plant-derived compound insecticide was prepared by combining the n-butanol phase extract of Sapindus mukorossi, the ethyl acetate phase extract of Rosa trifoliata, the chloroform phase extract of Dryopteris crassirhizoma, a solubilizer, and deionized water in a certain proportion.

5. The method for preparing the plant-derived compound insecticide for controlling armyworms according to claim 4, characterized in that, The method for preparing the Sapindus mukorossi n-butanol phase extract includes the following steps: S1. The peel of Sapindus mukorossi fruit is dried, crushed, sieved, extracted with ethanol, concentrated and dried to obtain Sapindus mukorossi ethanol extract. S2. Dissolve the ethanol extract of Sapindus mukorossi in deionized water, extract with n-butanol, then combine the extracts, concentrate under reduced pressure, and dry to obtain the n-butanol phase extract of Sapindus mukorossi.

6. The method for preparing the plant-derived compound insecticide for controlling armyworms according to claim 5, characterized in that, The specific steps of ethanol extraction are as follows: Weigh the sieved Sapindus mukorossi pericarp powder into an ethanol-water solution at a ratio of 1:10 (g / ml). Then, perform ultrasonic-assisted extraction three times under the following conditions: room temperature, ultrasonic power 20w, and extraction time 50min. Combine the extracts.

7. The method for preparing the plant-derived compound insecticide for controlling armyworms according to claim 4, characterized in that, The method for preparing the ethyl acetate phase extract of rotenone includes the following steps: (1) The whole plant of *Derris trifoliata* was dried, pulverized, sieved, extracted with ethanol, concentrated and dried to obtain *Derris trifoliata* ethanol extract; (2) The ethanol extract of rotenone was dissolved in deionized water and extracted with ethyl acetate. The extracts were then combined, concentrated under reduced pressure, and dried to obtain the ethyl acetate phase extract of rotenone.

8. The method for preparing the plant-derived compound insecticide for controlling armyworms according to claim 7, characterized in that, The specific steps of ethanol extraction are as follows: Weigh the sieved rotenone powder into an ethanol-water solution at a ratio of 1:10 (g / ml), and then perform ultrasonic-assisted extraction three times under the following conditions: room temperature, ultrasonic power 20w, and extraction time 50min. Combine the extracts.

9. The method for preparing the plant-derived compound insecticide for controlling armyworms according to claim 4, characterized in that, The method for preparing the chloroform phase extract of Dryopteris crassirhizoma includes the following steps: 1) Dry the stems and leaves of Dryopteris crassirhizoma, pulverize them, sieve them, extract them with ethanol, concentrate and dry them to obtain Dryopteris crassirhizoma ethanol extract; 2) The ethanol extract of Dryopteris crassirhizoma was dissolved in deionized water, extracted with chloroform, and then the extracts were combined, concentrated under reduced pressure, and dried to obtain the chloroform phase extract of Dryopteris crassirhizoma.

10. The method for preparing the plant-derived compound insecticide for controlling armyworms according to claim 9, characterized in that, The specific steps of ethanol extraction are as follows: Weigh the sieved Dryopteris crassirhizoma stem and leaf powder into an ethanol-water solution at a material-to-liquid ratio of 1:10 (g / ml). Then, perform ultrasonic-assisted extraction three times under the following conditions: room temperature, ultrasonic power 20w, and extraction time 50min. Combine the extracts.

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