On head and body movements of flying flies

Head and body movements of flies (Musca domestica and Calliphora erythrocephala) have been studied during sustained flight. Two main points emerge from the analysis: a) Changes in body direction and head direction occur simultaneously in almost all cases. b) During visually guided flight active neck movements are initiated together and in the same direction of body movements. This does not hold in absence of a visual pattern (“search”). Implications of these findings with respect to the organization of the control system underlying head-body coordination in flies are briefly discussed.