The distribution of the eggs of Mammalian Lice on their hosts. 2. Analysis of the Oviposition behaviour of Damalinia ovis (L)

Abstract

The behaviour pattern of Damalinia ovis (L.) is adapted to the physical features of the environment in which the louse lives. In stage 1, the louse was attracted to temperatures between 35 and 40°C and this temperature zone was necessary for oviposition to proceed satisfactorily. Optimum temperature conditions were between 37 and 39°C. In stage 2, the louse orientated itself so that its head was directed towards the warm end of a temperature gradient or towards the saturated end of a humidity gradient, but when these gradients were antagonistic the orientation to temperature dominated. At the commencement of stage 3, the louse reversed its orientation to both temperature and humidity gradients but again the attraction to temperature was dominant. Before egg laying commenced, a fibre of suitable diameter had to be caught by a gonopod and held next to the abdomen. The resulting tactile stimulus was critical and its absence inhibited oviposition. Other factors which influenced oviposition were the depressant effect of high humidities, the orientation to light, and the attraction to other ovipositing lice and eggs.