Use of an Acoustic Emission Detector for Locating Formosan Subterranean Termite (Isoptera: Rhinotermitidae) Feeding Activity when Installing and Inspecting Aboveground Termite Bait Stations Containing Hexaflumuron

Abstract

Soft- and hard-style aboveground bait stations containing 0.5% hexaflumuron in a cellulose matrix (Recruit R AG), were installed indoors in two condominium buildings and in one home. Bait stations were affixed to wood where Formosan subterranean termites [FST (Coptotermes formosanus Shiraki)] were observed in foraging tubes and subsurface galleries and adjacent to these locations where termite feeding was detected using an acoustic emission detector (AED). Bait stations were inspected monthly for the presence of termites, bait matrix consumption, and acoustic emission (AE) counts on adjacent wood. Bait stations were added as needed. Six to fourteen aboveground bait stations were installed in each structure at 3 or 6 placement sites. Termites fed in a mean of 73.3% of the stations installed to consume a total of 42-149 g of bait matrix. FST at the home had ground contact and consumed 2- 3.5 times more bait matrix than aerial infestations of FST at the condominiums. Acoustic emission counts generally declined from pretreatment levels at all monitoring locations following installation of the bait stations, with the exception of one condominium where AE counts peaked 6 weeks following installation. At all sites, bait matrix consumption in stations peaked during the first two months following installation of the aboveground bait stations. Baiting eliminated detectable FST activity in all structures, as indicated by lack of visual signs of termites and AED activity for at least two months. Elimination of detectable activity followed two or more months of bait matrix consumption by termites. Mean time to elimination of detectable activity for FST populations was 3.3 months (range 2-4 months).