Study On The Effect And Synergism Of 21 Botanical Substances On The Biological Activity Of Honeysuckle Aphids

Objective:This subject is to study the effect of 21 kinds of botanical substances on the biological activity of honeysuckle aphids,and to screen the plant-derived substances with higher aphidicidal activity.Through the compounding research of different plant-derived substances,a mixture combination with synergistic effect was screened.The compound medicament was loaded by hollow silica microspheres to prepare sustained-release microspheres,and its synergistic mechanism in preventing and controlling honeysuckle aphids was discussed.Methods:1.In this study,the capillary spot and disc method were used to determine the contact and stomach toxicity activity of 21 botanical substances against carrot microtubule aphid.2.In this experiment,the best compound and its ratio were selected by equivalent line method,Monsour method and Sun method.Use the method of soaking insects to test the toxicity of the mixture and judge whether the mixture has a synergistic effect.Potted plants and field trials were used to evaluate the effectiveness of the mixture against honeysuckle aphids.3.In this study,a soft template method was used to synthesize hollow silica microspheres as a carrier to prepare a sustained-release drug delivery system.The microspheres were characterized by transmission electron microscopy and other instruments,and the slow-release performance of the microspheres was analyzed by GC/MS.The effect of drug-loaded microspheres on the control of honeysuckle aphids was analyzed through the efficacy test and the changes in target leaf components.The wettability and retention of the microspheres on the target leaves were measured by contact Angle measuring instrument and scanning electron microscopy respectively to clarify the synergistic mechanism of the microspheres on the control of honeysuckle aphids.Results:1.The results showed that 21 kinds of botanical substances have different levels of contact and stomach toxicity to honeysuckle aphids.By analyzing the corrected mortality of aphids at 24,48,and 72 h after treatment,5 plants with strong aphidicidal activity were obtained.Source materials:Thymol,β-caryophyllene,trans-cinnamaldehyde,matrine,azadirachtin.2.In this study,the compounding of different plant-derived substances was studied,and three compound combinations with significantly synergistic effects were obtained as follows:16%thymol·β-caryophyllene,17%β-caryophyllene·matrine and 13%trans-cinnamaldehyde·azadirachtin.The toxicity test results showed that the three compound mixtures had enhanced virulence to the carrot microtubule aphid.The 17%β-caryophyllene·matrine mixture and the 13%trans-cinnamaldehyde·azadirachtin mixture were effective against the respective original drugs.Field trials found that 17%β-caryophyllene·matrine has the best control effect on honeysuckle aphids,and the control effect is about 61%and 91%after 1 and10 days of application.3.The optimal preparation conditions forβ-caryophyllene·matrine@NH₂-HMSN drug delivery system were obtained in the experiment:0.3000 g CTAB was dissolved in 60 m L absolute ethanol and 100 m L deionized water,and 2 m L concentrated ammonia was added under magnetic stirring.After stirring for 10 minutes,add 2 m L TEOS dropwise,and stir at room temperature for 6 hours.The white precipitate after centrifugation was expanded by cyclohexane,calcined in a muffle furnace and modified with amino groups to obtain NH₂-HMSN.The mass ratio ofβ-caryophyllene·matrine:NH₂-HMSN was 1:1 to prepare drug-loaded microspheres.The drug loading of the microspheres is about 36.13%,which has an obvious sustained-release effect,and the cumulative release rate after 288 h is greater than 80%.The efficacy test showed thatβ-caryophyllene·matrine@NH₂-HMSN has a good control effect on honeysuckle aphids,quick-acting,slow release of the drug,prolonging the efficacy time,and the control effect can reach 96%after 15 days of application.It can also repair the damage caused by aphids to the active ingredients of honeysuckle leaves.The synergistic study found thatβ-caryophyllene·matrine@NH₂-HMSN can enhance the affinity of the drug solution and the target leaf surface by improving the wettability and deposition performance of the drug solution on the target leaf surface.Conclusion:21 kinds of botanical substances have varying degrees of contact and stomach toxicity to carrot microtubule aphid.In the experiment,5 kinds of plant substances with high tactilicity and high gastric toxicity were selected to enhance the aphid killing activity of the original drug.The hollow silica microspheres loaded mixture is used to prepare drug-loaded microspheres,which effectively protects the active ingredients of the liquid medicine and improves the quick-acting,slow-release and sustained effect of preventing and controlling honeysuckle aphids.Therefore,the drug release can match the occurrence of aphids,play a role in controlling the population of aphids,and provide an important direction for safe,green and efficient prevention and control of honeysuckle aphids.