Study On Attractiveness Of Aldehydes And Terpenes To Mated Oriental Fruit Moth(Lepidoptera:Tortricidae)Females

Plant volatiles play a vital role in host plant choice.Oligophagous and polyphagous insects always exploit common compounds to guide all hosts.The oriental fruit moth(OFM),Grapholita molesta(Lepidoptera:Tortricidae),is a serious pest of stone and pome fruit trees worldwide,damaging young shoots and fruit.Its host range encompasses species within the family Rosaceae,Its principal host is considered to be peach,whereas pear is considered secondary host.The G.molesta have multiple generations per year and can switch hosts Baits with common compounds for capturing female G.molesta is potentially more advantageous to control the population density of G.molesta than a pheromone-based trapping strategy which would trap only males.Common compounds of all hosts not only cover host transferring mechanism,but also provide the new theoretic bases for control of G.molesta.We identified and quantified volatiles from peach and peach shoots using gas chromatography-mass spectrometry.We researched the relationship between common compounds and mated female G.molesta by eletroantennogram experiments,Y-tube bioassays,wind tunnel experiments,and field experiments.The main results was as follows:1)25 compounds were detected from peach(variety 'ShuGuang')using headspace adsorption,whereas 11 compounds were detected by SPME.In our SPME experiments,there was no difference between 65?n PDMS/DVB and 100?m PDMS,and between dynamic condition and static state.2)The common compounds of peach and peach shoots in there varieties were detected as nonanal,decanal,E-?-ocimene,and a-farnesene.3)In wind tunnel and oviposition preference tests,E-?-ocimene play main role in host orientation of female G.molesta and can stimulate spawning.4)In field tests,the trapped effect of OFM sex lure core would enhance 1.5times adding 10?g E-?-ocimene,or ?-farnesene.Further,1 mg of E-?-ocimene,also attracted G.molesta males.5)Eletroantennogram analysis showed that nonanal produoced the strongest response from the antennae of virgin and mated females.In Y-tube bioassays,only nonanal was attractive to mated G.molesta females amongst the four aldehydes,suggesting that nonanal is important for host recognition in G.molesta.In a field trial,each of the four aldehydes was tested as an attractant for both sexes of G.molesta.The traps baited with nonanal captured more female G.molesta,as compared to traps with other aldehydes and control;the traps baited with benzaldehyde captured most male G.molesta.Our research investigations provide theoretical foundation for biological control of G.molesta females.Future G.molesta lure designs should take into account sex-specific differences in the response to individual aldehydesIn our study,we found that E-?-ocimene play an important part in host preference and host orientation of female G.molesta,and it is a crucial oviposition stimulant for female G.molesta.We also found E-?-ocimene,and ?-farnesene act as sex pheromone synergists to enhance the attraction of male G.molesta to pheromone traps.We discovered peach-specific aldehyde nonanal attracts female.oriental fruit moths.Our research investigations provide theoretical foundation for biological control of G.molesta females.