Electrophysiological And Behavioral Responses Of Hyphantria Cunea To Several Volatiles From 11 Plants

Hyphantria cunea?Drury?is an important alien invasion pest in China.In order to investigate the effect of host and non-host volatiles on the host selection of H.cunea,this study selected 11 plants.Among them,Morus alba L.,Fraxinus chinensis L.,Ailanthus altissima?Mill.?Swingle,Ulmus pumila L.,Sophora japonica Linn.,Ulmus pumila L.cv.Jinye,Lonicera maackii?Rupr.?Maxim,Malus micromalus Makino and Platanus occidentalis L.are the host plant of H.cunea,Ginkgo biloba L.and Eucommia ulmoides Oliver are the non-host plant of H.cunea,and used the headspace dynamic collection method and gas chromatography-mass spectrometry?GC-MS?combined instrument to collect and identify plant volatile components.Principal component analysis was used to analyze the main volatile compound components and their relative contents of all tree species,and compared the differences in the composition and ratio of volatile compounds between host and non-host plants.The electrophysiological response and behavioral response of H.cunea of different states and genders to several plant volatile components were determined by using an electroantennogram?EAG?instrument and a wind tunnel device,and in order to find out the volatiles that were attractive or evasive to H.cunea.The main results were as follows:1. A total of 65 volatile components were identified from 11 tree species,which can be divided into6 chemical types.All tree species have their own unique volatile components,but the main components are similar which were mainly hydrocarbon compounds,and the total content were more than 80%.The common constituents between host and non-host mainly include?1S?-?-?-?-pinene,2,4-dimethylstyrene,isocitronene and n-heptadecane,and their relative contents had significant differences.All host plant contains only one unique volatile component,which was 2,4-dimethyl-1-heptene,and its average relative content was 0.710%.There were two unique volatile components contained in all non-host plants,which were 4-methylheptane and n-tetracosane.2. The electrophysiological response experiments were conducted on adults of H.cunea by using 5 kinds of plant volatiles,including 1 common component,3 different components of host and non-host plant volatiles and d-limonene,which was unique to G.biloba volatiles.The result showed that the five plant volatiles substances could cause different degrees of EAG responses in the adult H.cunea.For 2,4-dimethyl-1-heptene and d-limonene,the EAG relative response value of H.cunea increased significantly with the increase of concentration.When the concentration was 10^-1V/V,the response value to reach maximum.For 4-methylheptane,the EAG relative response value of the virgin female and male adults of the H.cunea were positively correlated with the concentration,while the EAG response value of the mated male was significantly higher at a concentration of 10^-3v/v decline.With the change of the concentration of n-tetracosane,there was a difference in the changing trends of the unmated female,male and mated females of the H.cunea that the virgin moths produced a significant change at a concentration of 10^-3V/V,while the mated females showed a steady upward trend.For Heptacosane,the EAG relative response value of the mated female was positively correlated with the concentration,while other adults did not change significantly with concentration.In general,the relative EAG response values of females to five volatile substances were significantly higher than males,and there were also significant differences in the EAG responses between females.3. According to the experimental results of electrophysiological response experiments,we selected n-tetracosane,2,4-dimethyl-1-heptene,4-methylheptane and d-limonene which could cause H.cunea's strongly electrophysiological response to conduct behavioral response of the H.cunea.For 2,4-dimethyl-1-heptene,all adults of the H.cunea showed positive behavioral responses,while during the reaction to 4-methylheptane,unmated moths showed avoidance behavioral responses,while mated female showed positive behavioral responses.D-limonene could cause the evasive behavior of virgin females of the H.cunea,while the males moths had no obvious tending behavior,and the mated females had no response to it.The flight data results showed that the flight time,upwind speed,angular speed and downwind speed of 2,4-dimethyl-1-heptene and 4-methylheptane of the H.cunea had significant differences.Therefore,it was inferred that 2,4-dimethyl-1-heptene would be a key volatile component of the H.cunea to recognize host plants,and 4-methylheptane would be a key volatile component of the H.cunea to recognize non-host plants.