Acoustical Detection of Early InstarRhynchophorus ferrugineus(Coleoptera: Curculionidae) in Canary Island Date Palm,Phoenix canariensis(Arecales: Arecaceae)

Abstract

ABSTRACT The red palm weevil (RPW), Rhynchophorus ferrugineus (Olivier), recently found in Curacao and Aruba, has become an economically significant palm tree pest in many tropical and subtropical regions. By the time a palm infested with RPW displays visible damage, larvae have destroyed much of the trunk internal structure, typically resulting in tree mortality. Acoustic technology may enable pest managers to detect and treat early RPW infestations before tree mortality, and to reduce unwanted importation and/or exportation of infested palms. Experiments were conducted in Aruba to determine the detectability of sounds produced by early instars in open, urban environments and in enclosures with ca. 10 dB acoustical shielding. To distinguish RPW signals from background noise, recordings first were analyzed to identify larval sound impulse bursts, trains of 7–199 impulses, 3–30-ms in duration, where impulses within the train were separated by less than 0.25 s. For a burst to be considered a larval sound, i...