Articles written in Proceedings – Animal Sciences
Volume 96 Issue 6 November 1987 pp 673-678
The terminal velocity of first instar
Volume 97 Issue 1 January 1988 pp 79-87
A unique club-shaped hair on the first instars of an Australian geometrid caterpillar is described. The sensory hairs occur on the body segments and is absent on the head and the last abdominal segment. These hairs have different orientations and are replaced by filiform hairs after the first moult. Regression lines describing the movement of hairs of different orientations in relation to a force is presented. With these results the deflection in the sensory hair due to gravity when the caterpillar is on a vertical plane was calculated. These calculations suggest that the hairs may not function as gravity receptors. The possible role of these hairs in the behaviour of caterpillars is discussed.