Studies on the stridulation of Hylotrupes Bajulus (L.) (Cerambycidae, Coleoptera): Communication through support vibration - Morphology and mechanics of the signal.

The stridulation of Hylotrupes bajulus (L.) is examined with respect to ethology and functional morphology. The morphology outlines a defined species-specific structure. Biophysical aspects of sound emission are discussed. The sound pattern of stridulation is described. Its time structure is species-specific. Only the vibrational component of stridulation is an effective signal in the intraspecific communication of H. bajulus . It is a part of aggressive behaviour, where it constitutes menacing or impressing elememts. It is also found within the mating behaviour, where it forms a part of the tactile stimulation of the female by the male beetle. The 'open' organisation of the behaviour analysed is of interest. This open arrangement of the behaviour is somewhat surprising in view of the complex differentiation of the morphology. The specifity of the ethological structure is discussed.