SENSORY EXPLOITATION AND THE EVOLUTION OF MALE MATING-BEHAVIOR - A CLADISTIC TEST USING WATER MITES (ACARI, PARASITENGONA)

The sensory exploitation hypothesis explains male secondary sexual characters as adaptations to exploit female responses that evolved in non-sexual contexts. The water mite Neumania papillator takes up a characteristic posture, the net-stance, in order to detect vibrations produced by copepod prey. Courting males vibrate their legs ('male courtship trembling') near females, and previous research shows that females respond to the vibrations as if they were produced by prey. The sensory exploitation hypothesis for male courtship trembling was tested by constructing a cladogram of N. papillator plus nine confamilial ingroup species and three outgroup species using 28 morphological and behavioural characters. Courtship and predatory behaviour were mapped onto the resultant tree. Net-stance evolved once and male trembling either evolved concomitantly with net-stance or twice thereafter. When taken together with previous behavioural evidence, this cladistic study strongly supports sensory exploitation as an explanation for male courtship trembling in unionicolid mites. © 1992 The Association for the Study of Animal Behaviour.