Ovipositor Internal Microsculpture in the Relic Silverfish Tricholepidion gertschi (Insecta: Zygentoma)

Abstract

The microsculpture on the inside surface of the ovipositor of the relic silverfish Tricholepidion gertschi (Wygodzinsky, 1961) (Insecta: Zygentoma) was studied with scanning electronic microscopy for the first time. Both the first and second valvulae of T. gertschi bear rather diverse sculptural elements: (1) microtrichia of various shapes and directed distally, (2) longitudinal ridges, (3) smooth regions, and (4) scattered dome-shaped sensilla. As in several other insects, the distally directed microtrichia most likely facilitate unidirectional movement of the egg during egg laying. Involvement of the ovipositor internal microsculpture also in the uptake of male genital products is tentatively suggested. From a phylogenetic point of view, the presence of internal microsculpture appears an ancestral peculiarity of the insect ovipositor.