BEHAVIORAL-RESPONSES OF DROSOPHILA-MELANOGASTER AND DROSOPHILA-SIMULANS ADULTS TO CONSPECIFICS

Adults of Drosophila melanogaster and D. simulans transmit and receive signals at some distance from their conspecifics. The behavioral responses differ according to species, sex and physiological state of the flies. Non-virgin D. melanogaster females increase their locomotor activity when male and female signals are received, without discriminating between the sexes. Non-virgin males of D. melanogaster do not increase dispersal in response to signals emitted by conspecifics, but they may avoid non-virgin females. Virgin and non-virgin flies of D. melanogaster move towards conspecifics when they detected flies of the sibling species D. simulans. However, virgin and non-virgin males and females of D. simulans are unable to discriminate the presence of physically distant conspecifics. It is argued that the substances referred to as sex pheromones may also serve to recognize physically distant conspecifics of Drosophila.