Distribution of Fat Body around the Air Sacs and Muscle Fibres in the Imago of Oryctes rhinoceros

Abstract

IN general, the fat bodies of insects are distributed in two anatomical positions: they exist as a peripheral layer beneath the epidermis and a perivisceral layer surrounding the alimentary canal. The lobes lie freely in the haemocoel; in most insects they are held in position by means of the tracheal branches, but in some the individual cells of the fat body seem to float freely in the haemocoel. In many insects the fat body fills all the available space within the body cavity, and can be seen to surround the visceral organs such as the gonads. They are never directly attached, however, to the organs, but are connected to them by means of tracheae. Recently, we have observed a unique distribution of the fat bodies in the imago of Oryctes rhinoceros.