Study On The Control Effects Of Essential Oil And Dichlorvos On Fruit Flies In Strawberry And Jujube

This paper studies the control of fruit fliesin strawberry picking garden and post harveststrawberries and jujubes,then,evaluated the safety of applying dichlorvos in strawberry-picking garden,and selected the fresh-keeping andinsect repellant methods which was safety and environmentally-friendly,due to the postharvest strawberries,jujubes wereready-to-eat and chemical safety was low.This paper studied the control effect of spraying and embedding dichlorvosonfruit flies,and analyzed the content of dichlorvos in soil and strawberries samples using HPLC and the repellent activity ofplant essential oil to fruit flies.The main compounds of litsea cubeba oil,ginger oil,calamus oilwere also detected by GC-MS.This paper formulated litsea cubeba oilmicrocapsule and litsea cubeba oil powder,then measured it's fresh-keeping and insecticide activity to strawberries,jujubes sent back by online retailers.The indoor toxicity and field efficacy test showed that dichlorvos had obvious lethal effecton third instars offruit flies,and the lethal dose(LC₅₀)ofdichlorvos to third instars offruit fliesat 24 hwas 20.84 mg/L.The control effect of sprayingdichlorvos on strawberry fruits at 12 h,1 d were 99.16%,90.73%,respectively,which were significantly higher than that in other ways.Embedding dichlorvos near the strawberry plants covered plastic film with holes had a persistent effect.This paper detected the content of dichlorvos in strawberries samples after beingapplied by spraying and embedding,and alsomeasured the the content ofdichlorvosin soil samples after beingapplied by embedding.The results showed that embedding dichlorvos near the strawberry plants covered by plastic film with holes was the highest security,and dichlorvos were mostly distributed in soil in the position of 0-5 cm from the embedding point.In the position of 5-20 cm dichlorvos were also detected,but the content were extremely low.The bioassay results showed that:calamus oil,Litsea cubeba oil,ginger oil had good repellent activity on fruit flies,and the repellent rates were 82.20%?71.73%?65.26%respectively after 5 min treatment.The results of GC-MS showed that?-citral and?-citral,?-zingiberen,?-asarone were the main component oflitsea cubeba oil,calamus oil,ginger oil.This paper studies the oviposition repellent and insecticide activityof litsea cubeba oilmicrocapsule which was prepared by embedding and litsea cubeba oil powder which was prepared by mixing to fruit fliesand strawberriesjujubes which were sent back by online retailers.The results showed that bothlitsea cubeba oilmicrocapsule and litsea cubeba oil powder could effective avoid fruit flies oviposting,reduce the amont of water lossand slow down the rate ofdecompose and avoid fruit flies oviposting of strawberries and jujubes sent back by online retailers.In addition,the effect of litsea cubeba oil powder was better than that of litsea cubeba oilmicrocapsule.litsea cubeba oilmicrocapsule which indicated that cinnamon leaf could play a synergistic effectcan the synergistic effect to litsea cubeba oil.The content of cinnamaldehyde?-citral and?-citralinstrawberries were higher than in jujubes,which may be related tothe strawberry epidermis is more rough than jujube epidermis.The content of?-citralin damaged strawberries and jujubeswere higher than intact strawberries and jujubes,which may be related to the higher content of water with which?-citralcould formehydrogen bondin the surface of damaged strawberries and jujubes.In this paper,the research results indicated that embedding dichlorvos near the strawberry plants covered plastic film with holes had a good control effect on fruit flies and the dichlorvoshad a low residue in strawberry.This paper found that litsea cubeba oilmicrocapsule and litsea cubeba oil powder with which effective components were litsea cubeba oil could effective avoid fruit flies oviposting,reduce the amont of water lossand slow down the rate ofdecomposeand avoid fruit flies oviposting of strawberries and jujubes sent back by online retailers.In addition,the effect of litsea cubeba oil powder was better than that of litsea cubeba oilmicrocapsule,and cinnamon leaf could play a synergistic effectcan the synergistic effect to litsea cubeba oil.