Fine structure, function and distribution of antennal sensilla in the saw‐toothed grain beetle, Oryzaephilus surinamensis

Abstract

ABSTRACT. Antennae of the saw‐toothed grain beetle (Oryzaephilus surinamensis L.) (Coleoptera: Silvanidae) were examined using scanning and transmission electron microscopy to determine the fine structure and distribution of sensilla. Seven morphologically different sensilla types are distinguished. Mechanoreceptor hairs account for over 68% of all sensilla. Mechanoreceptors are also found in conjunction with contact chemo‐receptors; this dual function is demonstrated by electrophysiological recordings. Three different types of olfactory chemoreceptor are found, accounting for 26% of all sensilla, plus two sensilla types with possible hygro/thermo‐receptor functions. Counts show the numbers of chemo‐receptors to be small, though this many simply reflect the small size of these beetles.