Preparation And Physicochemical Properties Of Attractant For Adult Sitotroga Cerealella

The Sitotroga cerealella(Olivier)is a major pest of grain storage in China and current control methods rely heavily on chemical pesticides,however there is an urgent need for safe and environmentally friendly green insecticide due to the serious “3R”problem.Previously,active substances extracted from maize and wheat were applied against the adult moths at certain concentrations and ratios,however the duration is not long enough.In this study,mesoporous silica nanoparticles(MSN)and cyclodextrin-functionalized mesostructured silica nanoparticles(CDMSN)were constructed as carriers for active substances to attract adult S.cerealella moths,and their physicochemical properties were analyzed to determine the duration of efficacy of the attractants.The main results were as follows:1.The study analyzed the effects of five solvents,namely ethyl ether,acetone,dichloromethane,hexane and liquid paraffin,on adult moths.The results indicated that three solvents,namely ethyl ether,acetone and liquid paraffin,had no effect on S.cerealella adult moths.Subsequently,nonanal and decanal were added to the three selected solvents to observe their effects on luring adult moths.The results showed that the adult moths attracted to the solvent made with liquid paraffin,which lasted for up to 5days,indicating that liquid paraffin was effective for that duration.Subsequently,liquid paraffin was chosen as the solvent for nonanal and decanal,and four types of microcapsules(A,B,C,and D)were prepared using the sol-gel method to create mesoporous silica nanomaterials and the one-pot method to prepare cyclodextrin-modified mesoporous silica nanomaterials as carriers with the addition of nonanal and decanal.2.The carriers and microcapsules underwent physico-chemical characterization,which involved the analysis of their characteristic functional groups using Fourier-transform infrared spectroscopy(FTIR).Using thermogravimetric analysis(TGA),drug loading capacity was evaluated,the results revealed that cyclodextrin had successfully modified mesoporous silica,and the loading capacity of microcapsules A,B,C,D was between 40% to 48%.The results of particle size analysis,scanning electron microscopy(SEM)and transmission electron microscopy(TEM)showed that the size of the microcapsules ranged from 100 nm to 300 nm,and the absolute value of the potential ranged from 30 m V to 45 m V.TEM analysis revealed that the shapes of the MSN and CDMSN carriers were elliptical.3.The biological activity of the microcapsules was assessed,and the results showed that the MSN-based microcapsules A and B attracted adult moths for 29 days longer than the control group,which lasted for 24 days.Furthermore,the CDMSN-based microcapsules C and D attracted moths for 43 days longer than the control group,which lasted for 38 days.Similarly,Simulated granary were carried out,and the results demonstrated that the MSN-encapsulated microcapsules A and B and CDMSN-encapsulated microcapsules C and D attracted moths for up to 22 and 29 days,respectively.Moreover,the microcapsules were evaluated on different temperatures and the results revealed that microcapsules A,B,C,and D were not effective at 15℃.However,at temperatures of 20℃,25℃,30℃,and 35℃,all four types of microcapsules possessed significantly higher attraction(above 40%)to the adult S.cerealella moths compared with control groups.In conclusion,it provides ideas for the preparation of plant-derived pesticides and provides a theoretical basis and scientific basis for the study of adult S.cerealella moths attractants.