No abstract

Mating behaviors of the predaceous spined soldier bug, Podisus maculiventris (Say) (Pentatomidae: Asopinae), were observed, and vibrational signals used in intraspecific communication were recorded and analyzed. Only males produced vibrational signals, using three different vibrational modes: vibration of the abdomen, percussion with the front legs, or tremulation of the body. When recorded on a nonresonant substrate (a loudspeaker membrane), the mean dominant frequency of signals produced by abdominal vibration varied between 90 and 140 Hz, and of tremulatory signals between 8 and 22 Hz. Percussion signals were broad-band, with the dominant frequency ≈97 Hz and lower amplitude spectral peaks between 1,500 and 3,000 Hz. In the courtship phase of mating behavior, males emitted pulse trains composed of an abdominal vibration after a tremulatory pulse. Females stimulated by signals of abdominal vibration and composite signals expressed searching behavior and orientation toward the source of vibration, whereas no specific reaction to tremulatory signals was observed. Observations of mating behavior and playback experiments showed that the abdominal vibration signals had both long range calling and short range recognition functions. Tremulatory signals were emitted at close range and were essential for copulation to occur. The sequences of fast and repeated percussion signals were emitted both as individual signals during calling and courting or between vibratory and tremulatory pulses. However, unlike the other vibrational signals, percussion did not seem to be emitted in a particular behavioral context, and its possible function in eliciting responses from females is unclear.

No abstract

Recent work suggests that closely related cerambycid species often share pheromone components, or even produce pheromone blends of identical composition. However, little is known of the pheromones of species in the subfamily Prioninae. During field bioassays in California, males of three species in the prionine genus Tragosoma were attracted to 2,3-hexanediols, common components of male-produced aggregation pheromones of beetles in the subfamily Cerambycinae. We report here that the female-produced sex pheromone of Tragosoma depsarium “sp. nov. Laplante” is (2R,3R)-2,3-hex-anediol, and provide evidence from field bioassays and electro-antennography that the female-produced pheromone of both Tragosoma pilosicorne Casey and T depsarium “harrisi” LeConte may be (2S,3R)-2,3-hexanediol. Sexual dimorphism in the sculpting of the prothorax suggests that the pheromone glands are located in the prothorax of females. This is the second sex attractant pheromone structure identified from the subfamily Prioninae, and our results provide further evidence of pheromonal parsimony within the Cerambycidae, in this case extending across both subfamily and gender lines.