Description du comportement sexuel de Calliphora vomitoria (Diptera: Calliphoridae) par une technique d'analyse de textes.

Description of the sexual behaviour of Calliphora vomitoria (Diptera: Calliphoridae) with a lexical analysis software package. The sexual behaviour of Calliphora vomitoria was described using a lexical analysis software package considering courtship as a series of words, without any arbitrary categorization. Normal as well as manipulated partners of both sexes were presented to the males. Results showed that normal courtship and copulation occurred when the wings were modified but present and correctly oriented, whereas perturbations were observed and copulation disappeared after inversion and various head modifications. Missing elements (head and wings) were less disruptive than their inversion. If the partner was supposed to be scanned from the head to the abdomen via the wings and if it was supposed to perceive the relative position of these different parts, it is obvious that the absence of an element did not act as an error message and courtship and copulation were preserved. On the other hand, inversion of the same elements seemed to induce wrong or inconsistent informations affecting courtship structure, probably because of sequence disturbance. The courtship preservation in front of every kind of manipulation leads us to question what image of the sexual partner is constructed.

Les modalités de communication dans le comportement sexual de Calliphora vomitoria (Diptera: Calliphoridae): vers une interprétation de la parade.

During sexual behaviour, the body and the behaviour of the partner provide a pattern of distant or contact signals. In order to evaluate in which respect courtship behaviour and its success depend on the comparison between the male's expectancy (template) and its actual perception, we have presented to male flies partner bodies with modified odours or shapes or both from different sexes and ages. Our data demonstrated the simultaneous use of different sensory channels. They suggest two different processes which might be involved in the construction of the template. Firstly, it could result from sensory reafferences, with a shuttle between stimuli and responses. In that case, the mismatch between expectancy and actual perception might induce disturbances in the courtship behaviour. If the differences are too high, it could stop the courtship sequence which resumes at its beginning. Secondly, the template could result from a process of representation. Then, when expectancy does not fit the perceived image, courtship would not be disturbed and the male could extract a new significance from the network of stimuli provided by the partner's body.