Study On Semiochemicals Of Two Kinds Of Lepidoptera Insect

The objective of this thesis is divided into two parts: one is the identification of sex pheromone of the carpenterworm moth, Holcocerus hippophaecolus Hua, the other is to study on semiochemicals of Helicoverpa. Armigera from its host origin.Gas chromatography, gas chromatography-mass spectrometry, and derivatization with dimethyl disulfide were used to identify chemicals from the female sex pheromone gland of the carpenterworm moth, Holcocerus hippophaecolus Hua, a pest of sandthorn, Hippophae rhamnoides L. Total seven chemicals were found as sex pheromone. they were (ï¿¡)-3-tetradecenyl acetate (E3-14:Ac), (Z)-3-tetradecenyl acetate (Z3-14:Ac), (Z)-7-tetradecenyl acetate (Z7-14:Ac), the corresponding alcohols, E3-14:OH, Z3-14:OH, Z7-14:OH, and (ï¿¡)-9-tetradecenyl acetate (E9-14:Ac). Electroantennographic (EAG) analysis of the gland chemicals and their analogs demonstrated mat Z7-14:Ac elicited the largest response, followed by E3-14:Ac. In field trials, traps baited with either Z7-14:Ac or E3-14:Ac alone caught no male moths, while the combination of these two components in a ratio of 1:1 caught significantly more males than other ratio and control traps. Addition of the alcohols, Z7-14.OH and Z3-14:OH or the alcohols plus E9-14:Ac did not significantly enhance male catches in the field. We conclude that the sex pheromone of H, hippophaecolus is composed of a (1:1) blend of Z7-14:Ac and E3-14:Ac. Pheromone-baited traps could be used to monitor populations of H. hippophaecolus, serving a role in an integrated pest management program for sandthorn in China.The EAG responses of the female and male adults of H.armigera to a range of host-plant volatile components were examined. The results showed that the antennae of both male and female moths could response to a wide variety of host-plant volatile components. There were no significantly different responses between the female and male moth antennae. The oviposition tests showed that the presence of some host-plant volatile components greatly increased the attractiveness for oviposition, The field tests showed the attractiveness of sex pheromone plus host-plant volatile component was significantly higher than that of sex pheromone alone. In this thesis, the EAG responses of female Helicoverpa armigera (HUbner) to the single or mixture of volatile component of the wheat blossom were examined. For single compound or mixture compounds, there were no significant different between EAG responses of virgin females and mated females (P<0.05). But, when Heptanal, with the consistency of 1 X 10"5 -5X 10~5(V/V), add to the mixture of green-leaf volatile compounds, the antenna of mated female of cotton bollworm strongly responded to the mixture of compounds with significent different as compounds to that the virgin female (P<0.05).