Abstract: To elucidate the parsimony of floral volatiles to Helicoverpa armigera, we determined the effects of two key floral volatiles, phenylacetaldehyde and benzyl acetate, on the ovipositional choice, sex pheromone trapping, and neonatal approaching behavior. The oviposition bioassay shows that the percent of eggs deposited by mated females on the gauze covered on the binary blend of phenylacetaldehyde and benzyl acetate did not differ from those covered on all the host leaves (hot pepper, tobacco, cotton, and maize) but tomato leaves, suggesting that these floral volatiles had fairly strong ovipositional attractiveness. The addition of floral attractant to H. armigera sex pheromone could enhance the field trap catch of H. armigera moths, and the trapping of other moth species, such as Argyrogramma agnate, Agrotis ypsilon, Spodoptera exigua, Ostrinia nubilalis, Cnaphalocrocis medinalis, and Hymenia re-curvalis,  was not influenced by the presence of H. armigera sex pheromone, indicating that the floral attractant had good compatibility with H. armigera sex pheromone. Additionally, the floral volatiles could enhance the perception of neonates to tobacco leaf discs. Taken together, floral volatiles have multiple ecological functions to H. armigera, and this semiochemical parsimony might be favored by natural selection.

Key words: state-space method, optimum population, carrying capacity, Jilin Province.