A Causal Ethological Analysis of the Courtship Behaviour of an Insect (the Parasitic Wasp Nasonia Vitripennis, Hym., Pteromalidae)

Abstract

AbstractWe focus on the causal organization of courtship behaviour of an insect, i.c. that of the pteromalid wasp Nasonia vitripennis, a parasite of the pupae of various flies. We observe uninterrupted displays of male Nasonia, and analyse temporal structures in order to infer causal relations between display elements. These relations are put to a test by manipulations: displays are interrupted at pre-defined points, or re-started after pauses of various durations, or specific motor patterns are prevented from being executed. The results are summarized in Fig. 13, in which we outline the structure of the underlying organization. The main conclusion is that the performance of courtship is a self-inhibiting process in which head-nodding behaviour (a component of the display) appears to play a key role. Inhibitive effects deteriorate during pauses in between displays (in a non-linear way), but also - albeit less extensively - in periods of non-nodding, during the display itself. We discuss the issue of similar or different principles of organization in courtship behaviour of insects and vertebrates. Although a common basis cannot be excluded, we have to leave open a more definite conclusion for the time being.