The communicative behavior of five species and subspecies of
Tropisternus Solier (Coleoptera: Hydrophilidae) was studied. These
aquatic beetles have stress and calling chirps (both sexes), a second
male calling signal (one species), a single male courtship sound
(usually), a male copulatory sound, and a female aggressive rejection
buzz (three species)....
Three sympatric species of Ips, colonizing Sitka spruce, were
investigated with regard to their infestation habits, stridulating
apparatus and acoustic signals. The above phenomena are evaluated
qualitatively and/or quantitatively and the acoustic signal differences
are proposed as a possible factor for maintaining species isolation,
although function is not shown.
Field...