Mating Behavior of Letana inflata, a Duetting Phaneropterine Bush-Cricket Species with Unusual Male Genitalic Organs (Orthoptera: Tettigonioidea: Phaneropteridae)

Abstract

In the mate recognition system of bush-crickets (Tettigonioidea) two character complexes are most important: acoustic communication for long-distance attraction and genital fitting during the actual mating process. Here we describe these both components for Letana inflata, a species of the subfamily Phaneropterinae in which the females typically do not approach the singing males phonotactically but respond with their own acoustical signals to the male song. In this duet males and females use extremely short signals. As a calling song the males produce mainly one single loud impulse of less than one millisecond duration, which is answered by the female after about half a second again only with one or up to three short loud impulses. Male and female signals have similar carrier frequencies, although their stridulatory organs are not homologous and possess different forms. When mating, males and females engage in an unusually prolonged copulation which lasts more than three hours. Most phaneropterine species studied before mate for less than four minutes. The long duration may be related to the presence of a titillator (phallic sclerite), not present in most phaneropterines studied so far, and a very unusually shaped male subgenital plate which allows the male a stable hold of the female ovipositor. Already 30–60 min after beginning of the copulation the males were found to carry the sperm-containing ampulla inside their body with the tip of the ampulla being in contact with the female genital opening. The mating behavior is discussed especially in comparison with the other tettigonioid species with prolonged copulation.