Stridulatory Apparatus and Analysis of the Acoustics of Four Species of the Subfamily Lamiinae (Coleoptera: Cerambycidae)

Investigation of 4 species of the subfamily Lamiinae—Tylocerina nodosus (F.), Neacanthocinus obsoletus (Olivier), Monochamus titillator (F.), and Plectrodera scalator (F.)—shows that both sexes of each species produce a stridulatory sound when disturbed. The stridulatory apparatus of each species consists of a plectral ridge on the inner surface of the posterior margin of the pronotum and a pars stridens on the dorsal surface of the mesocutellum of the mesothorax. Scanning electron micrographs show the plectral ridges to be smooth, while the pars stridens consists of regularly spaced striae with height, width, and spacing measurements characteristic for each species. Audiospectrographic analysis of the beetle-produced sounds reveals definite frequency bands, pulse lengths, and relative intensities for each species. Investigation of behavioral aspects of the sounds indicates that they are not a necessary component of courtship and mating behavior, but they may serve as an alarm signal.