The Synergistic Electroantennogram Responses of Spodoptera litura to Plant Volatiles and Sex Pheromones

Abstract The common cutworm Spodoptera litura (Lepidoptera: Noctuidae), an important pest of tobacco, has substantial detrimental effects on many crops production. Sex pheromone has been widely used in pest forecasting and controlling. Plant volatiles as a kind of synergists may provide more efficient services to avoid the limitation of sex attractant in comprehensive trapping pests. To improve the effectiveness of its female-produced sex pheromone were evaluated using electroantennography. The 21 volatile compounds were tested in S.litura, several compounds with strong responses were selected and compared the responses of different concentrations, different proportions and mixed preparation. The both females and males had strong responses by Benzaldehyde, Heptaldehyde, cis-3-Hexen-1-ol, Ethyl benzoate, Myrcene, Benzyl alcohol, with the increase of concentrations, the EAG response values also increased gradually. Cis-3-Hexen-1-ol was mixed with Heptaldehyde, the strongest responses of females and males were elicited when the ratio was 9:1 and 8:2, respectively. And cis-3-Hexen-1-ol mixed with Myrcene, the strongest responses were elicited when the ratio was 1:1 and 3:7. Heptadehyde mixed with Benzyl alcohol, the strongest responses were elicited when the ratio was 1:9 and 6:4. Also, three formulations including single Heptaldehyde, the mixture of cis-3-Hexen-1-ol and Heptaldehyde, the mixture of cis-3-Hexen-1-ol and Myrcene were strongly significantly enhanced the EAG responses of the moths to sex pheromone. This study demonstrates the capability of S. litura females and males to detect and discriminate among different volatiles,and provides a theoretical basis for further olfactometer and field trapping works.