Sound-producing mechanisms of Buenoa macrotibialis Hungerford (Hemiptera: Notonectidae)

Abstract

In Buenoa macrotibialis, experimental results indicate that the stridulatory mechanism composed of the tibial combs and rostral prongs is involved in producing trills, chirps, and dart-chirps; the femoral ridges and coxal peg mechanism is involved in producing grasping-chirps and cleaning-chirps; and the forelegs probably stridulate in unison. Either half of the tibial comb can produce trills, chirps and dart-chirps, though these signals are usually altered from normal. Both combs are normally involved in signal production, but one tibial comb can produce these signals with only slight alterations. The frequency spectrum of acoustic signals of macrotibialis is generated by resonation, not by rate of stridulation. The body proper, or some part(s) thereof, apparently functions as the resonator. Vibrations created by stridulation of the tibial comb-rostral prong and femoral ridge-coxal peg mechanisms probably are transmitted to the resonator by the rostrum and/or coxae.