Behavioral And Electrophysiological Responses Of Plutella Xylostella Adults To Volatiles From Different Host Crops

Plutella xylostella(Linnaeus)is a worldwide migratory pest that causes great harm to Cruciferae crops.Adults rely on the well-developed sense of smell to locate the volatiles of host plants to complete mating,oviposition and other life activities.In this experiment,the relationship between the host plant volatiles and the oviposition of P.xylostella was explored,and the single compound that can cause electrophysiological and behavioral responses of P.xylostella was determined by various techniques.The main test results are as follows:1.Composition of volatiles from 7 host crops of P.xylostellaThe volatiles of Brassica chinensis L.、Brassica napus L.、Brassica juncea L.、Raphanus sativus L.、Brassica campestris L.、 Brassica oleracea L.、 Brassica oleracea L.var.botrytis L.were collected by headspace technology,and analyzed by GC-MS.A total of 81 volatiles from 7 Cruciferae crops were collected.The contents of esters,alcohols and hydrocarbons were relatively high;the volatiles of seven plants all contained leaf alcohol,and isothiocyanates were identified in Brassica juncea L.、 Raphanus sativus L.and Brassica oleracea L..2.Identification of volatile active substances from 7 host plants of P.xylostellaBased on the results of GC-MS,12 active substances were screened out from the volatiles of 7 host crops of P.xylostella by GC-EAD,which were hexanal,1-penten-3-ol,trans-2-hexen-ol,benzaldehyde,n-nonanal,acetophenone,isopropyl isothiocyanate,allyl isothiocyanate,butyl isothiocyanate,3-hexanone,cis-3-hexenol-1-ol and cis-3-hexenyl acetate.This step is the core part of the whole research content,and it is the key step to connect the smell of P.xylostella with plant volatiles.3.Electrophysiological response of P.xylostella adults to active substances in volatiles of host plantsAccording to the EAG reaction results,the EAG response of female P.xylostella to n-hexanal,cis-3-hexenol-1-ol,1-penten-3-ol,trans-2-hexenol,benzaldehyde,isopropyl isothiocyanate and allyl isothiocyanate was always greater than that of male,but the opposite was true for butyl isothiocyanate;the effects of the concentrations of n-nonanal,acetophenone,cis-3-hexenyl acetate and 3-hexanone on the EAG response of P.xylostella is more complicated.4.Behavioral response of P.xylostella adults to volatiles from host plantsThe selection behavior of male and female P.xylostella to compounds was studied by Y-tube.The results showed that n-hexanal,1-penten-3-ol,trans-2-hexenol,benzaldehyde,acetophenone,cis-3-hexenol,cis-3-hexenacetate,isopropyl isothiocyanate,butyl isothiocyanate and 3-hexanone could attract female adults in different concentrations and degrees;n-hexanal,1-penten-3-ol and 3-hexanone could attract female adults in different degrees.N-hexanal,1-penten-3-ol,trans-2-hexenol,n-nonanal,benzaldehyde,acetophenone,cis-3-hexenol-1-ol,cis-3-hexenacetate,isopropyl isothiocyanate and butyl isothiocyanate all had attraction to male adults at different concentrations;n-nonanal had no attraction to female P.xylostella at four concentrations,and 3-hexanone had attraction to male adults at four concentrations.In addition,allyl isothiocyanate at a concentration of 500 μ g / μ l had a repellent effect on male and female P.xylostella.