Antennal sensilla and electrophysiological response of male and female Spodoptera frugiperda (Lepidoptera: Noctuidae) to conspecific sex pheromone and plant odors

The olfactory system of male and female Spodoptera frugiperda (J. E. Smith) was studied by examining the morphology and distribution of antennal sensilla and determining the responses of both sexes to conspecific female sex pheromone components and plant volatiles using electroantennography (EAG). Seven types of sensilla were observed on the flagellum of the antennae: trichodea, chaetica, coeloconica, styloconica, auricilica, squamiformia, and basiconica. Only one type of trichodea sensilla was found on the antennae of both sexes, but these sensilla were more abundant on male than on female. EAG records of both sexes to 10-µg stimulus loads of six pheromone components showed that (Z)-7-dodecenyl acetate (Z7-12: Ac) and (Z)-9-dodecenyl acetate (Z9-12: Ac) elicited larger responses than those evoked by (Z)-11-hexadecenyl acetate (Z11-16: Ac), (Z, E)-9,11-tetradecadienyl acetate (Z9, E11-14: Ac), (Z, E)-9,12-tetradecadienyl acetate (Z9, E12-14: Ac), and hexane in female antennae. In the case of male antennae, (Z)-9-tetradecenyl acetate (Z9-14: Ac) and Z9, E12-14: Ac evoked larger EAG responses than those elicited by Z7-12: Ac, Z11-16: Ac, Z9, E11-14: Ac, and hexane.