Acoustic characteristics of dynastid beetle stridulations

Abstract

Oryctes rhinoceros (L.) (Coleoptera: Scarabaeidae: Dynastinae) causes economically important damage to ornamental and commercial coconut palm trees in the western Pacific region that could be mitigated significantly by early detection and treatment. Adults are difficult to detect visually because they attack the crowns of the trees and feed internally before mating and dispersing to new hosts. Visual inspection is nevertheless the most widely used detection method, augmented with pheromone traps. This species is an ideal candidate for acoustic detection because the adults are large, active borers that produce stridulations during courtship and mating. The stridulations have distinct, easily recognized temporal patterns. Larvae and pupae also produce stridulations. To assist in development of new detection methods, acoustic characteristics of the adult and larval stridulations have been quantified and compared with stridulations produced by larvae of other dynastids recorded in the western Pacific region.