Comparison of courtship songs in Cotesia (Hymenoptera: Braconidae)

Acoustic signals play an important role in premating isolation based on sexual selection across many taxa. Within several genera of parasitic wasps, males produce a characteristic courtship song that is used by females to identify conspecifics and/or assess mate quality. In Cotesia, courtship songs are generated by wing fanning and pulses in stereotypical patterns. We compared male courtship songs among 10 of ca. 80 described Cotesia species in North America, including eight species that have not been recorded previously. Songs of emergent males from wild caterpillar hosts in five different families were recorded with miniature omnidirectional microphones in a noise reduction booth. Pattern, frequency, and duration of song components were analyzed using Raven Pro. Species-specific songs varied significantly in structure and duration of repeating pulse and buzz components, and in fundamental frequency (175 to 328 Hz). Differences in courtship songs generally mirrored the most recent proposed molecular phylogeny for Cotesia spp. by Michel-Salzat & Whitfield (2004) in that songs of more closely related species were more similar than those of more distantly related species. Courtship song analysis may aid in identifying closely related cryptic species and provide insight into the evolution of this highly diverse and agriculturally important taxon.