High frequency and counterstroking: calopteryx splendens female threatening flight

Abstract

A hitherto unknown flight pattern of female Calopteryx splendens is described. On a day with heavy winds, when no damselfly could fly in open space of the river, I observed and filmed four to six females foraging in a small bay sheltered by bank vegetation. Females fought for perches and showed a threatening flight with counterstroking and high frequency wing-beating. In all other female flight modes the fore and hind wings were beaten nearly in parallel with a much lower beat frequency. As the newly observed flight mode resembles the courting flight mode of males of C. splendens the female’s threatening flight is compared with it. At landings of both sexes the wings were beaten in a counterstroking mode for one to seven beats, as well. The possible development of female’s threatening flight from wing beating during landing of C. splendens is discussed. The relevance of these findings is to extend the knowledge about the variety of flight modes in Calopteryx females.