Reconstruction and morphometry of silkmoth olfactory hairs: A comparative study of sensilla trichodea on the antennae of male Antheraea polyphemus and Antheraea pernyi (Insecta, Lepidoptera)

Abstract

Olfactory trichoid hairs on the antennae of male Antheraea silkmoths were reconstructed with respect to the following parameters: number, shape, course, and dimensions of outer dendritic segments as well as the numbers of their microtubules; inner and outer dimensions of the cuticular hair shafts; and number and distribution of pores and pore tubules in the hair walls. The smallest distances between dendritic membranes and inner hair surfaces were determined with respect to the possibility of pore tubule contacts. It was shown that most hairs contain one thick and one, or frequently two, thin dendrites. The number of microtubules in the dendrites is correlated with dendrite diameter, which decreases towards the hair tip. The dendrites form numerous swellings and constrictions: this “beading” occurs especially along the thin dendrites. The dendrites do not run straight, but rather follow a sinuous course in the hairs. The density of wall pores is lowest in the basal region of the hairs. Only in relatively few places do the dendritic membranes get near enough the hair walls to come into the probable range of the pore tubules. In the sensilla trichodea of A. polyphemus, the hairs as well as the dendrites have markedly smaller diameters than in A. pernyi.