Plant-derived insecticide, its preparation method and application

Abstract

The plant source insecticide contains effective components of parathion and avermectin, the weight ratio of parathion and avermectin is 10-50:1, and is supplemented with an acceptable agricultural adjuvant to form one of emulsifiable concentrate, wettable powder, water dispersible granule, water emulsion or suspension agent suitable for agricultural use, and belongs to the field of pesticides. The plant source insecticide shows activity on peridroma saucia, aphid and cotton red spider, especially high acaricidal activity on red spider. The prevention and treatment effect on citrus red spider is obviously improved after parathion and avermectin are compounded, which shows that the combination of parathion and avermectin has significant synergistic effect on citrus red spider. Parathion is derived from Chinese herbal medicine plant, and there is no problem of pesticide residue, and the risk of drug damage is greatly reduced. At the same time, the two single agents of the composition have great difference in chemical structure and completely different action mechanism, and there is no cross resistance, which can delay the resistance problem caused by the use of the two single agents alone.

Description

Technical Field

[0001] This invention belongs to the field of pesticides, specifically relating to a plant-derived insecticide, its preparation method and application. The plant-derived insecticide contains the active ingredients alloponoside, or alloponoside and abamectin. Background Technology

[0002] Plant-derived pesticides are receiving increasing attention and have become the preferred choice for green biological pesticides. Compared with traditional chemically synthesized pesticides, they have obvious advantages: (1) plant-derived pesticides are generally easier to degrade in the environment; (2) they have target specificity and are relatively safe for humans, animals and non-target organisms after use; (3) they have more active ingredients and unique modes of action, making it difficult for pests to develop resistance; (4) some plant-derived pesticides have non-toxic modes of action, including attraction, repellency, antifeedant effects, sterilization, and regulation of growth and development, which are more extensive than the modes of action of chemically synthesized pesticides.

[0003] Armyworms, also known as leafhoppers, are highly prolific and can cause outbreaks in a short period. After the third instar, their appetite increases dramatically, and they develop stronger pesticide resistance. They primarily damage rice, corn, and wheat, and in severe outbreaks, they can also harm beans and cabbage, significantly impacting crop yield and quality. Broad bean aphids belong to the genus *Aphid* in the family Aphididae of the order Hemiptera. They are heteroparasitic aphids with extremely high reproductive rates and are a common pest of broad beans, affecting them throughout their entire growth cycle. Aphids suck plant sap, causing stunted growth, curled leaves, and prevented flower buds from opening, leading to premature aging and decay. Aphids can also carry viruses, entering the plant through their sucking wounds and causing secondary infections. Citrus red spider mites, also known as citrus spider mites or citrus carrion mites, are a widespread pest in my country's pomelo-producing areas and are currently one of the most serious pests affecting citrus-growing regions. Besides citrus plants, this mite can also damage cherry, persimmon, apple, pear, grape, walnut, jujube, papaya, tea, mulberry, rose, magnolia, geranium, nandina, canna, and marigold. The citrus red mite has 12-20 generations per year, with overlapping generations. Adults and nymphs use their piercing-sucking mouthparts to pierce the epidermis of leaves, branches, and fruits, sucking sap and chlorophyll. Sucking sap from leaves causes them to lose their luster and develop chlorotic spots; severely affected leaves turn grayish-white and fall off, hindering flowering and fruiting.

[0004] Currently, the control of armyworms, bean aphids, and spider mites mainly relies on the spraying of chemical insecticides, including imidacloprid, omethoate, methamidophos, pyridaben, abamectin, and trichlorfon. Chemical insecticides are generally toxic and can cause poisoning in humans or livestock through ingestion, skin, or respiratory tract during spraying, endangering health. Furthermore, chemical insecticides have single-component formulations, making it easy for pests to gradually develop resistance. In addition, the peak period for spider mites coincides with the flowering and fruiting period of citrus trees. Many chemical pesticides contain halogens, leading to slow degradation of the effective insecticidal components, leaving pesticide residues on the citrus fruit. When the citrus fruits enter the market, this can harm human health. Therefore, to address the shortcomings of existing methods, it is essential to research a plant-based pesticide that can be extracted from plants, is harmless to the environment and humans / animals, has a simple preparation method, and has good insecticidal and acaricidal effects. Simultaneously, to reduce pest resistance, mixtures of different active compounds can be used to control pests. By combining active compounds with different mechanisms of action, the development of resistance can be delayed, the application rate can be reduced, the control effect can be improved, and the control cost can be reduced.

[0005] The root bark of *Jasminum giraldii* Diels, belonging to the Oleaceae family, is also known as Shan Jiu Jia or Xiao Liu Guai. It is distributed in Shaanxi, northwestern Hubei, and the border region of Shanxi, Gansu, Henan, Sichuan, and Shaanxi. As a characteristic medicinal material of the Qinling-Bashan region, it has the effects of promoting blood circulation, removing blood stasis, promoting tissue regeneration, and astringing. It is mainly used to treat traumatic injuries, internal blood stasis, fractures, and knife wounds. The main active components in *Jasminum giraldii* Diels are secoidoids, such as jasminoside. These compounds are formed by cleavage at C7 and C8 of secoidoids and are often precursors of indole alkaloids in their biosynthesis. Currently, there are no reports on the insecticidal and acaricidal effects of jasminoside or its use in combination with other insecticides and acaricides. Summary of the Invention

[0006] The purpose of this invention is to provide a plant-derived insecticide, its preparation method, and its application. The plant-derived insecticide contains the active ingredients alloponoside, or alloponoside and abamectin.

[0007] Biopangcha glycoside is a characteristic iridoid glycoside extracted from the bark of the citrus tree. It is used for the prevention and control of crop diseases and pests, especially for the control of citrus red spider mite disease.

[0008] The technical solution for implementing the present invention is as follows:

[0009] A plant-derived insecticide containing the active ingredient phenanthrene, the structural formula of which is shown in the figure below.

[0010]

[0011] The plant-derived insecticide also contains abamectin, with a weight ratio of allopanthene to abamectin of 10–50:1.

[0012] The plant-derived insecticide, with the addition of phenanthrene and pesticide-acceptable excipients, is formulated into one of the following formulations suitable for agricultural use: emulsifiable concentrate, wettable powder, water-dispersible granule, emulsion, or suspension concentrate.

[0013] The plant-derived insecticide, baicalin, and abamectin, are formulated with pesticide-acceptable excipients into one of the following formulations suitable for agricultural use: emulsifiable concentrate, wettable powder, water-dispersible granule, emulsion, or suspension concentrate.

[0014] The preparation method of the plant-derived insecticide, namely, allopanthene, is carried out according to the following steps:

[0015] (1) Soaking: Take the dried root bark of Jasminum sambac, namely, the root bark of Jasminum sambac, crush it with a high-speed pulverizer, pass it through a 20-mesh sieve, add 95% ethanol, soak it for 48 hours with stirring, filter it, and evaporate the filtrate to obtain the crude extract of root bark.

[0016] (2) Precipitation: The crude extract of *Cynanchum paniculatum* was suspended in a 20-40% low-concentration ethanol aqueous solution and allowed to settle to obtain the supernatant of the *Cynanchum paniculatum* extract.

[0017] (3) Extraction: The supernatant of the extract of the root bark was extracted with an equal volume of ethyl acetate and dried by rotary evaporation to obtain the total extract of iridoid glycosides, of which the content of allopanthene glycosides was more than 60%.

[0018] (4) Preparation of monomeric compounds: The monoclonal compounds were separated by D101 macroporous adsorption resin and further purified by recrystallization to prepare bacontin with a purity of over 95%.

[0019] The plant-derived insecticide is used in the preparation of insecticides, and the insects include one of the following: mites, armyworms, broad bean aphids, and spider mites.

[0020] The plant-derived insecticide is used in the preparation of insecticides, and the spider mites are one of the following: cotton spider mite, citrus spider mite, and loofah spider mite.

[0021] The application of the aforementioned allopanthene as the sole component in the preparation of plant-derived insecticides, and the preparation method of the aforementioned allopanthene, are carried out according to the following steps:

[0022] (1) Soaking: The dried root bark of Jasminum sambac, namely, the root bark of Jasminum sambac, was crushed by a high-speed pulverizer, passed through a 20-mesh sieve, and then soaked in 95% ethanol for 48 hours with stirring. After filtration, the filtrate was evaporated to obtain the crude extract of the root bark.

[0023] (2) Precipitation: The crude extract of *Cynanchum paniculatum* was suspended in a 20-40% low-concentration ethanol aqueous solution and allowed to settle to obtain the supernatant of the *Cynanchum paniculatum* extract.

[0024] (3) Extraction: The supernatant of the extract of the root bark was extracted with an equal volume of ethyl acetate and dried by rotary evaporation to obtain the total extract of iridoid glycosides, of which the content of allopanthene glycosides was more than 60%.

[0025] (4) Preparation of monomeric compounds: The monoclonal compounds were separated by D101 macroporous adsorption resin and further purified by recrystallization to prepare bacontin with a purity of over 95%.

[0026] The application of the plant-derived insecticide in the preparation of insecticides can inhibit protein synthesis in citrus red spider mites.

[0027] Beneficial effects:

[0028] 1. This invention uses the dried root bark (Quanpi) of Jasminum sambac as raw material. After pulverization, the crude extract of Quanpi is extracted by soaking in methanol or ethanol. The crude extract is suspended in a low concentration of alcohol and water, and the supernatant is extracted with ethyl acetate to enrich the total iridoid glycoside extract (with a content of more than 60% of phenothiazines). The obtained total iridoid glycoside extract is separated by D101 macroporous adsorption resin, and further purified by recrystallization to obtain iridoid glycoside compounds with a purity of more than 95%—phenothiazines.

[0029] 2. The present invention conducted indoor insecticidal activity tests on the obtained baicalin. At a general screening concentration, it showed activity against armyworms, broad bean aphids and cotton red spider mites, especially high acaricidal activity against red spider mites, and can be developed as a novel plant-derived pesticide.

[0030] 3. The two active ingredients in the composition of this invention exhibit a synergistic effect, which is more significant than the individual activity of a single compound. Furthermore, the two individual agents in the composition have significantly different chemical structures and completely different mechanisms of action, eliminating cross-resistance and thus mitigating resistance issues that may arise from using either agent alone. Attached Figure Description

[0031] Figure 1 The chemical structural formula of phenanthrene. Detailed Implementation

[0032] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the description of this invention, those skilled in the art can make various alterations or modifications to the invention, but these equivalent forms also fall within the scope defined by the appended claims.

[0033] Example 1: Preparation of allopanthene

[0034] 1 kg of dried root bark of *Jasminum sambac* (also known as *Cistanche deserticola* root bark) was weighed, pulverized using a high-speed pulverizer, and passed through a 20-mesh sieve. Ten times the amount of 95% ethanol was added, and the mixture was soaked for 48 hours with continuous stirring. The mixture was then filtered, and the filtrate was evaporated to dryness to obtain 154 g of crude extract of *Cistanche deserticola* root bark. The crude extract was suspended in 20% ethanol and allowed to stand for 24 hours to obtain 300 mL of supernatant. After extraction with an equal volume of ethyl acetate, 66 g of total iridoid glycoside extract (containing more than 60% of *Bephanoside*) was obtained. The total extract was adsorbed using 1.5 times the amount of D101 macroporous adsorption resin. First, 2 BV (column volume, the same below) of 10% ethanol was used to wash away sugars, proteins, and inorganic salts. Then, 3 BV of 20% and 30% ethanol were used for elution, and finally 3 BV of 40% ethanol was used for elution, yielding five fractions (1-5). Fractions 2 and 3 were recrystallized to obtain 34 g of *Bephanoside*, with a yield of 3.4% and a purity >96%.

[0035] The following are the data from the proton NMR spectrum:

[0036] Allopanthenoside: White solid; 1H NMR (400MHz, MeOD) δ 7.53 (s, 1H), 5.88 (s, 1H), 5.17 (d, J = 7.9 Hz, 1H), 4.74 (dd, J = 7.8, 2.8 Hz, 1H), 4.39 (d, J = 7.7 Hz, 1H), 4.34 (d, J = 14.3 Hz, 1H), 4.21 (d, J = 14.4 Hz, 1H), 4.14 (d, J = 12.0 Hz, 1H), 3.89 (d, J = 11.9 Hz, 1H) ,3.78(dd,J=12.0,6.9Hz,1H),3.73(s,3H),3.67(d,J=12.1Hz,1H),3.58–3.50(m,1H),3.40(t,J=9.0Hz,1H ),3.31–3.13(m,7H),2.85(dd,J=16.1,8.3Hz,1H),2.73(t,J=7.8Hz,1H),2.20(dd,J=15.4,7.4Hz,1H).13C NMR(100MHz,MeOD)δ168.18,151.95,143.43,127.62,111.01,103.44,99.21,97.42,76.61,76.50,76.4 4,76.38,73.78,73.41,70.33,70.27,68.39,61.41,60.08,50.31,45.65,38.36,35.36.HRMS(ESI)calcd for C 26 H 30 NaO 13 [M+Na]+573.1790, found 573.1770.

[0037] Example 2: Preparation of allopanthene

[0038] 1 kg of dried root bark of Jasminum sambac (also known as *Cistanche deserticola* root bark) was weighed, pulverized using a high-speed pulverizer, and passed through a 20-mesh sieve. Ten times the amount of 95% ethanol was added, and the mixture was soaked for 48 hours with continuous stirring. The mixture was then filtered, and the filtrate was evaporated to dryness to obtain 148 g of crude extract of *Cistanche deserticola* root bark. The crude extract was suspended in 30% ethanol and allowed to stand for 24 hours to obtain 250 mL of supernatant. After extraction with an equal volume of ethyl acetate, 60 g of total iridoid glycoside extract (containing more than 60% of *Bephanoside*) was obtained. The total extract was adsorbed using 1.5 times the amount of D101 macroporous adsorption resin. Sugars, proteins, and inorganic salts were first washed away with 2 BV of 10% ethanol, followed by elution with 3 BV of 20% and 30% ethanol, and finally with 3 BV of 40% ethanol, yielding five fractions (1-5). Fractions 2 and 3 were recrystallized to obtain 35 g of *Bephanoside*, with a yield of 3.5% and a purity >96%.

[0039] Example 3: Preparation of allopanthene

[0040] 1 kg of dried root bark of Jasminum sambac (also known as *Centella asiatica* root bark) was weighed, pulverized using a high-speed pulverizer, and passed through a 20-mesh sieve. Ten times the amount of 95% ethanol was added, and the mixture was soaked for 48 hours with continuous stirring. The mixture was then filtered, and the filtrate was evaporated to dryness to obtain 150 g of crude extract of *Centella asiatica* root bark. The crude extract was suspended in 40% ethanol and allowed to stand for 24 hours to obtain 220 mL of supernatant. After extraction with an equal volume of ethyl acetate, the extract was enriched to obtain 58 g of total iridoid glycoside extract (containing more than 60% of *Bephanoside*). The total extract was adsorbed using 1.5 times the amount of macroporous adsorption resin. Sugars, proteins, and inorganic salts were first washed away with 2 BV of 10% ethanol, followed by elution with 3 BV of 20% and 30% ethanol, and finally eluted with 3 BV of 40% ethanol, yielding five fractions (1-5). Fractions 2 and 3 were recrystallized to obtain 31 g of *Bephanoside*, with a yield of 3.1% and a purity >96%.

[0041] Example 4: Preparation of Allantoin Plant Insecticide

[0042] The following mass ratio was used to prepare the plant insecticide emulsion of phenothiazines: 50% phenothiazines prepared in Example 1, 40% methyl oleate, and 10% Tween-80 with an HLB value of 15. The specific preparation method is as follows: phenothiazines were dissolved in methyl oleate, and then Tween-80 with an HLB value of 15 was added and dissolved to obtain the product.

[0043] Example 5: Preparation of a plant-based insecticide containing allantoin

[0044] The following mass ratio was used to prepare the plant insecticide emulsion of phenothiazines: 40% phenothiazines prepared in Example 1, 50% methyl oleate, and 10% Tween-80 with an HLB value of 15. The specific preparation method is as follows: phenothiazines were dissolved in methyl oleate, and then Tween-80 with an HLB value of 15 was added and dissolved to obtain the product.

[0045] Example 6: Preparation of insecticide solution of allopanthene composition [allopanthene·avermectin (50:1)]

[0046] The insecticidal emulsifiable concentrate of the allamandaine composition was prepared according to the following mass ratio: 50% allamandaine prepared in Example 1, 1% abamectin, 39% methyl oleate, and 10% Tween-80 with an HLB value of 15. The specific preparation method is as follows: allamandaine and abamectin were dissolved in methyl oleate, and then Tween-80 with an HLB value of 15 was added and dissolved to obtain the final product.

[0047] Example 7: Preparation of insecticide solution of allopanthene composition [allopanthene·avermectin (30:1)]

[0048] The insecticidal emulsifiable concentrate of the baicalein composition was prepared according to the following mass ratio: 48% baicalein prepared in Example 1, 1.6% abamectin, 40.4% methyl oleate, and 10% Tween-80 with an HLB value of 15. The specific preparation method is as follows: baicalein and abamectin were dissolved in methyl oleate, and then Tween-80 with an HLB value of 15 was added and dissolved to obtain the final product.

[0049] Example 8: Preparation of insecticide solution of allopanthene composition [allopanthene·avermectin (10:1)]

[0050] The insecticidal emulsifiable concentrate of the baicalein composition was prepared according to the following mass ratio: 45% baicalein prepared in Example 1, 4.5% abamectin, 40.5% methyl oleate, and 10% Tween-80 with an HLB value of 15. The specific preparation method is as follows: baicalein and abamectin were dissolved in methyl oleate, and then Tween-80 with an HLB value of 15 was added and dissolved to obtain the final product.

[0051] Example 9: Indoor insecticidal activity determination of allopanthene against armyworm, broad bean aphid and cotton red spider mite

[0052] Experimental methods: The product of styrax glycoside (JS) prepared by the method of Example 1, the crude extract of citronella bark (QP-1) prepared by the method of Example 1, and the control drugs (imidacloprid IM and bifenazate BI) (purchased from Jiangsu Suke Agrochemical Co., Ltd.) were used to test the activity of each against armyworm, broad bean aphid and cotton red spider.

[0053] Preparation of the reagent: After weighing, the original drug was dissolved in N,N-dimethylformamide (DMF) to obtain 1×10 5The stock solution was diluted to the required concentration with an aqueous solution containing 0.2% Tween 80.

[0054] Armyworm viability test: A spray method was used. Corn leaf segments of roughly the same size were placed in a 90mm petri dish lined with filter paper, and then 10 third-instar larvae were introduced. The dish was placed under a Potter spray tower for spraying. The spray volume was 2mL / 10 larvae, with each treatment repeated 4 times. After treatment, the dishes were placed in a recovery room for incubation. Mortality was checked and recorded after 72 hours, and the mortality rate was calculated.

[0055] The broad bean aphid was controlled using a spraying method. Broad bean seedlings infested with 3-day-old broad bean nymphs were uprooted and placed in a beaker filled with water. The beaker opening was sealed with parafilm and secured with a plastic gasket. An electric sprayer was used to spray the seedlings at a rate of 2 mL per plant, with each treatment repeated four times. After the plants dried, they were covered with a kerosene lamp and placed in a recovery room for incubation. After 48 hours, mortality was checked and recorded, and the mortality rate was calculated.

[0056] Cotton red spider mites were controlled using a spraying method. Two-leaf, one-heart stage broad bean seedlings infested with adult spider mites were uprooted and placed in a beaker filled with water. The beaker opening was sealed with parafilm and secured with a plastic gasket. An electric sprayer was used to spray the seedlings at a rate of 2 mL per plant, with each treatment repeated four times. After the plants dried, they were covered with a kerosene lampshade and placed in a recovery room for incubation. After 72 hours, mortality was checked and recorded, and the mortality rate was calculated.

[0057] Calculation method

[0058]

[0059]

[0060] P t —Morbidity rate in the treatment group, expressed as a percentage (%);

[0061] P0—Morale rate of the control group, in percentage (%);

[0062] After 48 or 72 hours, check and record the mortality of the test insects. Based on the mortality rate of the insects at different concentrations, calculate the toxicity test results of phenothiazines against armyworms, broad bean aphids and cotton red spider mites, as shown in Table 1.

[0063] Table 1. Results of toxicity tests of the present invention against armyworms, broad bean aphids, and cotton red spider mites.

[0064]

[0065] Results and Analysis: The crude extracts of baicalein and baicalein showed activity against armyworms, broad bean aphids, and cotton spider mites. At a concentration of 200 mg / L, they exhibited a mortality rate of at least 50% against armyworms and excellent activity (80%) against broad bean aphids. In particular, they showed high acaricidal activity against spider mites, with a mortality rate exceeding that of the commercially available bifenazate at a concentration of 50 mg / L.

[0066] Experiments showed that both phenothiazines and crude extracts of senna bark exhibited activity against armyworms, broad bean aphids, and cotton red spider mites at the general screening concentration. In particular, they showed high acaricidal activity against red spider mites and could be developed as novel plant-derived pesticides. Moreover, data indicated that the refined phenothiazines product was more effective than the crude extract of senna bark.

[0067] Example 10: Field efficacy experiment of allopanthene and its composition against citrus red spider mite disease

[0068] To clarify the field efficacy of iridoid glycosides—alphazoside and its combinations, the applicant conducted field efficacy trials on the agent.

[0069] Experimental methods: The insecticide prepared in Example 4 was labeled as Sample 1, commercially available abamectin was labeled as Sample 2, and the insecticides prepared in Examples 6-8 were labeled as Samples 3-5. Referring to the implementation method in Example 1 of Chinese Patent Publication No. CN 106613548A, 50% propargite at a dilution of 1500 times was used as a comparative sample for the control of citrus red spider mites.

[0070] The experimental gradient settings are shown in Table 2.

[0071] Table 2 Gradient settings for field experiments on citrus red spider mite disease

[0072]

[0073] A citrus orchard of the same age was divided into seven experimental plots, each spaced more than 50 meters apart. Following standard citrus management methods, insecticides were sprayed during the peak period of spider mite infestation. Five plots were sprayed with samples 1-5, one plot was sprayed with a control sample, and the remaining plot served as a blank control, sprayed with an equal volume of water. Spider mite populations were counted before spraying and recorded as pre-treatment populations. Spider mite populations were counted again before and 2 hours after spraying (only observation of poisoning was conducted, without recording the results), 24 hours after spraying, and 72 hours after spraying.

[0074] Calculation formula:

[0075] Insect population reduction rate: Insect population reduction rate (%) = (Number of live insects before treatment - Number of live insects after treatment) / Number of live insects before treatment × 100

[0076] Corrected insect population reduction rate: Corrected insect population reduction rate (%) = [1 - (insect population before blank control treatment × insect population after treatment in the control area) / (insect population after treatment in the blank control area × insect population before treatment in the control area)] × 100

[0077] Check the mortality of the test insects after 24 or 72 hours and record the results. Calculate the corrected insect population reduction rate, as shown in Table 3.

[0078] Table 3. Statistical results of the reduction in the population of citrus red spider mite.

[0079]

[0080] As shown in Table 3, the citrus red spider mite insecticide prepared in this invention achieved corrected insect population reduction rates of 31.89%, 32.11%, 36.90%, and 47.16% for the four treatments 24 hours after spraying, indicating moderate overall rapid-acting properties. At 72 hours after spraying, the corrected insect population reduction rates for the four treatments were 70.66%, 74.26%, 81.92%, and 91.31%, respectively, demonstrating good overall performance. The control efficacy of baicalin alone was comparable to the control sample, but its efficacy against citrus red spider mites was significantly improved when combined with abamectin, indicating a significant synergistic effect between the two. Furthermore, field results showed that the insecticide prepared in this invention was safe for use on citrus, exhibiting no significant risk of phytotoxicity. Therefore, the baicalin and its composition prepared in this invention achieve control efficacy comparable to chemical insecticides, and as a plant-derived insecticide, it offers the advantage of greater safety.

[0081] Example 11: Effect of allopanthene on protein content in citrus red spider mite

[0082] Experimental method: The protein content in the insect body was determined by Coomassie brilliant blue colorimetric method using the product of the method in Example 1 (JS).

[0083] Preparation of the reagent: After weighing, the original drug was dissolved in N,N-dimethylformamide (DMF) to obtain 1×10 5 The stock solution was diluted to the required concentration with an aqueous solution containing 0.2% Tween 80.

[0084] Coomassie Brilliant Blue G-250 reagent: Weigh 100 mg of Coomassie Brilliant Blue G-250, dissolve it in 50 mL of 95% ethanol, add 100 mL of 85% phosphoric acid, and dilute to 1000 mL with distilled water.

[0085] Bovine serum albumin standard solution: Weigh 10 mg of bovine serum albumin and dissolve it in 100 mL of distilled water to obtain a stock solution of 100 μg / mL.

[0086] Determination of protein concentration in citrus red spider mites: 200 female adult mites were treated with 1 mL of different gradient pesticide solutions (200, 100, 50 mg / L) for 8 hours. The mites were then homogenized with 1 mL of distilled water, allowed to stand for 30 minutes, and centrifuged at 10,000 rpm for 20 minutes. The supernatant was pipetted and diluted to 2 mL with distilled water to obtain the protein extract. 0.05 mL of the protein extract and 0.05 mL of physiological saline were placed in a stoppered graduated test tube (0.01 mL of physiological saline was added for the blank control). 5 mL of Coomassie Brilliant Blue G-250 reagent was added to each tube, mixed thoroughly, and allowed to stand for 2 minutes until no more bubbles appeared. The OD value was then measured using a quartz cuvette. 595 The protein content per milliliter of solution can be obtained from the standard curve, and the results are shown in Table 4.

[0087] Table 4 Gradient settings for field experiments on citrus red spider mite disease

[0088]

[0089] Table 4 shows that 8 hours after treatment with different gradient pesticide solutions, berberine had a certain effect on the protein content in citrus red spider mites. Compared with the control, the protein content in the high, medium, and low dose berberine treatment groups decreased by 43.46%, 32.15%, and 25.18%, respectively. The reason for this phenomenon may be that berberine poisoned the test insects, causing them to break down their internal proteins for energy, or inhibited their protein synthesis, leading to metabolic disorders.

[0090] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A plant-derived insecticide, characterized in that, It contains the active ingredients bacontin and avermectin, with a weight ratio of bacontin to avermectin of 10–50:

1.

2. The plant-derived insecticide as described in claim 1, characterized in that, Allopontoxin and abamectin, combined with pesticide-acceptable excipients, can be formulated into one of the following formulations suitable for agricultural use: emulsifiable concentrate, wettable powder, water-dispersible granule, emulsion, or suspension.

3. The plant-derived insecticide as described in claim 1, characterized in that, The preparation method of the aforementioned allopanthecoside is carried out according to the following steps: (1) Soaking: Take the dried root bark of Jasminum sambac, namely, the root bark of Jasminum sambac, crush it with a high-speed pulverizer, pass it through a 20-mesh sieve, add 95% ethanol, soak it for 48 hours with stirring, filter it, and evaporate the filtrate to obtain the crude extract of root bark. (2) Precipitation: The crude extract of *Cynanchum paniculatum* was suspended in a 20-40% low-concentration ethanol aqueous solution and allowed to stand to precipitate, thus obtaining the supernatant of the *Cynanchum paniculatum* extract. (3) Extraction: The supernatant of the extract of the root bark was extracted with an equal volume of ethyl acetate and dried by rotary evaporation to obtain the total extract of iridoid glycosides, of which the content of allopanthene glycosides was more than 60%; (4) Preparation of monomeric compounds: The monosodium glutamate was prepared by separation using D101 macroporous adsorption resin, recrystallization and further purification, with a purity of over 95%.

4. The application of the plant-derived insecticide as described in claim 1 in the preparation of insecticides, characterized in that, The insects include one of the following: mites, armyworms, bean aphids, and spider mites.

5. The application of the plant-derived insecticide as described in claim 4 in the preparation of insecticides, characterized in that, The red spider mite mentioned is one of the following: cotton red spider mite, citrus red spider mite, or loofah red spider mite.

6. The application of the plant-derived insecticide as described in claim 5 in the preparation of insecticides, characterized in that, Inhibits protein synthesis in citrus red spider mites.

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