CONTRASTS IN THE TERRITORIAL BEHAVIOUR OF THREE SPECIES OF HOVER FLIES (DIPTERA: SYRPHIDAE)

Abstract

Among territorial syrphids, males of Eumerus tuberculatus (Rond.) are less aggressive than Merodon equestris (Fab.) and Eristalis tenax (L.) males. This difference in aggressiveness persists even when territorial pressures increase with increasing numbers of conspecifics.Males of each species recognized conspecific females mainly by a combination of visual and behavioural cues. A territorial male might approach any intruder, but would only attempt to mate if, like the appropriate female, the intruder did not respond to the male's approach. Differences in behavioural patterns may be due to different mating strategies.