Sound Production in Scolytidae: Aggressive and Mating Behavior of the Mountain Pine Beetle

Abstract

Dendroctonus ponderosae Hopkins males emitted interrupted chirps both while fighting a rival male and when attracted into a virgin female's gallery. Behavior accompanying interrupted chirps was aggressive in both contexts. Females became silent and permitted entry when chirping males touched them, but chirped continuously, attacked, and usually ejected surgically silenced males, indicating a premating recognition function for the ♂ interrupted chirp. Non-aggressive, courting behavior occurred in the gallery as ♂ stridulation changed to simple, uninterrupted chirps just before mating. Females responded to ♂ stridulation at the gallery entrance by simple, multi-impulse chirps similar to the ♀ territorial chirp reported earlier. The ♀ chirp is not emitted during courtship and appears to be mainly a territorial response to intruders. Phonostimulus of acoustic response between the 2 sexes, in addition to the previously shown olfactory response, is now established.