Abstract: The volatiles of stem tip, square and flower of cotton, male flower and female filament of corn, celery, leaf and flower of peanut possessing attraction activities to cotton bollworm (CBW) Helicoverpa armigera (Htibner) were extracted onto TenaxTA or Tenax GR and collected with hexane separately. Electroantennography (EAG) was used to explore the electrophysiological responses of CBW to the tested volatiles,The amplitude values of receptor potential ranged from 0.1 to 1.2mV. The EAG responses of virgin female to the volatiles of square, flower and stem tip of cotton and flower and seedling of peanut increased with its age (1-10 days old). The mated females had significantly stronger EAG responses than the virgin females, suggesting that these plants emit some chemicals which are capable to promote the oviposition of females. The curves of dosage-EAG amplitude showed that mating can significantly reduce the threshold of female electrophysiological responses to the volatiles of stem tipand flower of cotton. The results of four-arm olfactometer tests indicated that the CBW moths were strongly attracted by these plant volatiles. The selective indices to cotton square, cotton tip, corn silk and peanut were 0.78, 0.61, 0.49 and 0.31 respectively.

Key words: cotton bollworm, olfactory, EAG, allelochemics