AN EXPERIMENTAL ANALYSIS OF THE COURTSHIP PATTERN OF TIPULA OLERACEA (DIPTERA)

Abstract

The courtship pattern of Tipula oleracea consists of a complex series of reciprocal stimulus–response reactions. The sequence of the reactions (grabbing, mounting, pinning, searching, kissing, and sliding reaction) is rigidly fixed, whereas the procedure of a reaction exhibits a certain degree of flexibility. Courtship may be broken off at any point between the males' grabbing response and the actual copulation if a reaction cannot be completed, a sign stimulus is missing, or a sign stimulus is given at the wrong time.The grabbing and the pinning reactions of the stimulus–response pattern have a specific "filter effect" leading to the copulation of active males with unfertilized, receptive females and preventing a mating between two males or between a male and a fertilized or too young female. The grabbing reaction is also involved in the prevention of an interspecific mating.