A NOVEL, LOCALIZED TREATMENT USING SPINOSAD TO CONTROL STRUCTURAL INFESTATIONS OF DRYWOOD TERMITES (ISOPTERA: KALOTERMITIDAE)

Abstract:
Intragallery application of 0.23% or 0.5% spinosad (suspension concentrate, SC) resulted in 98-100% drywood termite mortality in a laboratory simulated gallery bioassay and significantly reduced drywood termite activity, as measured using an acoustic emissions detector (AED), in a comparative field trial through one year posttreatment. In the same trials, currently available localized treatments (Tim-bor and PT-270) provided inconsistent or incomplete reduction in drywood termite mortality. Tim-bor, (10% disodium octaborate tetrahydrate, DOT) applied as an intragallery treatment or surface treatment, did not result in mortality significantly different from untreated controls in the laboratory bioassay and did not have significantly lower termite activity by 5 months after surface treatment in the field trial. Intragallery application of Tim-bor dust (98% DOT) performed better in laboratory bioassays, but not in the field trial, compared to Tim-bor liquid treatments. Intragallery application of PT270 (0.5% chlorpyrifos aerosol) resulted in variable termite mortality in the laboratory trial and did not result in significant reduction in termite activity by 2 months after treatment in the field trial. In the field trial, drywood termite activity recovered in all treatments except spinosad SC by one year after application. Pest control operators demonstrated they could effectively use spinosad SC and the acoustic emissions detector to significantly reduce termite activity by a mean of 94%, with at least 90% or greater reduction in 89% of the treated infestations.