SEM Study of Insect Tissue Using Ethanol-Infiltrated Cryofracture Followed by Critical Point Drying

Abstract

Transmission electron microscopy has been used for most ultrastructural study of insect tissue. This is particularly true for investigations of glands associated with the insect epidermis and cuticle (1). The advent of ethanol-infiltrated cryofracture of biological tissue followed by critical point drying, however, enables closer examination of surface topography and three dimensional conformation of glands and other structures associated with the insect cuticle by scanning electron microscopy (2).In the queen honey bee (Apis mellifera L.), a wide band of gland cells is located beneath tergites three, four and five of the abdomen, called subepidermal glands (3). Epidermal cells and modified epidermal cells, tormogen cells, are also found beneath the cuticle near the subepidermal glands (4).Scanning electron microscopy of ethanol-infiltrated fractured tergites of the queen honey bee which have been critical point dried revealed that the subepidermal gland cells were spherical in shape (Fig. 1).