Fine structure of the body wall cuticle of females of Bellodera utahensis and Ekphymatodera thomasoni (Sarisoderini, Heteroderinae)

Abstract

The female body wall cuticle of Bellodera utahensis and Ekphymatodera thomasoni (Heteroderinae) has an external sub-crystalline layer and four concentric layers, A, B, C, and D. Surface striae of the cuticle of B. utahensis are transverse, whereas those of E. thomasoni are longitudinal. The surface patterns are reflected in the A layer, which is thickest in the elevated regions between striae. The B layer consists of vertical columns and is continuous in young females but is broken into discontinuous patches as the female increases in girth. The C layer and adjacent D layer tend to merge at an intermediate zone in B. utahensis and E. thomasoni. The D layer is composed of fibrils about 31 nm in diameter arranged in a helicoidal pattern. An E layer adjacent to the hypodermis is present only in B. utahensis. The D layer is not resolved in newly molted females of B. utahensis, contrary to E. thomasoni. The presence of a D layer is a phylogenetic character shared with most other Sarisoderini. Although further investigation of Rhizonema and Hylonema is needed, existing knowledge of the body wall cuticle in females strengthens hypotheses of the monophyly of Sarisoderini.