Wing morph-related differences in the pattern of mating activity in a flightless bug, Pyrrhocoris apterus (L.) (Heteroptera)

Abstract

Summary The mating activity of the long-winged (macropterous) and short-winged (brachypterous) adult males and females from a temperate population (Czech Republic) of the firebug Pyrrhocoris apterus (L.) was studied during the first 14 days of adult life under constant laboratory conditions. The study showed that macropterous pairs copulated almost three times less frequently than the brachypterous pairs. The mean inter-copulation period was significantly longer in macropterous females than in brachypterous ones. Despite the fact that there was no significant difference between the total courtship frequencies of macropterous and brachypterous males, the mean duration of the inter-mating period was significantly shorter in brachypterous males than in macropterous ones, which indicates higher mating vigour of the former. Thus, the lower mating propensity of macropterous pairs was mainly due to lowered receptivity of females and in some extent to lowered mating vigour of males. The courtships of males and copulations of pairs of both wing morphs occurred predominantly throughout the photophase. The mean (peak) time of courtship and copulation activities of brachypterous pairs occurred at about 17:30 MET and 19:00 MET before the onset of the scotophase, respectively. In macropterous pairs the mean peak time of courtship and copulation occurred 2 h earlier. The study showed that the wing morph-related differences in mating activity characteristic for many flying wing-polymorphic insects are maintained also in insects whose all macropterous specimens have evolved flightlessness.