Host Plant Selection Behavior And Related Attracting Compounds Of Adult Agrotis Segetum

Agrotis segetum(Lepidoptera:Noctuidae),omnivorous pest,is widely distributed in Asia,Europe and Africa.It is mainly feed on cotton,corn,wheat,sugar beet and other economic crops and caused seriously damage in crops.Currently,chemical communication mechanisms between A.segetum and its main host plants in China is still unclear.A.segetum relies principally on volatiles of host plants to locate,mate and oviposit.Antenna is the major organ of the insects to detect host volatiles.In order to systematic assess the chemical communication mechanisms of A.segetum in China,this paper studied the behavioral and electroantennogram responses of A.segetum to volatiles of host plants by combining with indoor cage spawning,wind tunnel,Y-tube olfactometer,GC-EAD and GC-MS technologies and methods.The main findings are as follows:Indoor cage spawning and wind tunnel test have confirmed there were five host plants attracted female A.segetum adults,including Gossypium hirsutum L.,Abutilon theophrasti M.,Sesamum indicum L.,Solanum nigrum L.and Chenopodium album L..Among those five tested plants,A.theophrasti was determined that have the significant attraction to oviposition of female A.segetum adults by indoor spawning experiment.In Y-tube olfactometer bioassays,male and female A.segetum adults both obviously responded to the smell of G.hirsutum.and A.theophrasti,and there was no significant difference between males and females.Using GC-EAD,fourteen active volatile compounds were selected from the collected plant volatiles.And they were identified to Octane,3,3-dimethyl-,Eucalyptol,Octane,2,3,6,7-tetramethyl-,Benzene,1,2diethyl-,Benzene,1,4-diethyl-,2-Methylnonane,Butanoic acid,butyl ester,Nonanal,4-Isopropoxy-2butanone,4-Decene,7-methyl-,(E)-,1-Decene,2,4-dim ethyl-,Nonane,2,6-dimethyl-,Nonane,5-(2methylpropyl)-,Octane,5-ethyl-2-methyl-with GC-MS.EAG results shown that low concentration of six active volatiles(Eucalyptol,Benzene,1,2-diethyl-,Benzene,1,4-diethyl-,2-Methylnonane,Butanoic acid,butyl ester and Nonanal)were weakly response to EAG amplitude of A.segetum adults,and EAG does-dependent responses revealed that the EAD relative value is increasing with the concentrations of above six compounds increased.The wind tunnel experiment further confirmed six active volatiles(Octane,3,3-dimethyl-,Eucalyptol,Benzene,1,2-diethyl-,Benzene,1,4diethyl-,Butanoic acid,butyl ester and Nonanal)have significant attractive effects on female A.segetum adults.In Y-tube olfactometer bioassays,the visual cues of LED lights(white,red,yellow and green lightemitting diodes)had significant attraction to female A.segetum adults.The attraction strength from strong to weak was white LED(450～458 nm),yellow LED(587～590 nm),red LED(615～618 nm)and green LED(515～518 nm)lights.The active compounds which attracted to female adult A.segetum were selected and assessed.Overall,this study results provided scientific evidence for further understanding of interaction between A.segetum adults and their host plants and behavior regulation strategy of A.segetum based on the chemical identification.Practically,it is also benefit for the development of plant source attractant product of A.segetum adults.