Response of Pteromalus cerealellae to conspecific odor: Evidence for female- and male-produced pheromones?

Pteromalus cerealellae (Ashmead) (Hymenoptera: Pteromalidae) is an ectoparasitoid of several pests of stored products. We investigated the role of semiochemicals in mediating intraspecific communication in this parasitoid using electroantennogram (EAG) and behavioral bioassays. Responses of virgin male and female P. cerealellae were tested to airborne volatiles from live male and female conspecifics and to whole body extracts of both sexes. Females showed significantly greater EAG responses than males to whole body extracts of both sexes. Results from Y-tube olfactometer bioassays demonstrated significant attraction of both sexes to live conspecifics of the same (intrasexual attraction) or opposite sex (cross attraction). Females also showed significant attraction to whole body extracts of females, but not to the extract of males. These findings provide preliminary evidence for possible existence of a female-produced sex pheromone and close range cuticular chemicals by both sexes of P. cerealellae, which may play a role in courtship and species recognition. Further studies are needed to characterize these chemicals and determine their roles in the behavioral ecology of P. cerealellae.

► Pteromalus cerealellae is a parasitoid of larvae of stored product insects.
► We investigate response of both sexes to conspecific odor.
► Both sexes are attracted to live conspecifics of the same or opposite sex.
► Results provide evidence for existence of sex-related pheromones in the parasitoid.