Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/3/2014
Publication Date: 4/1/2014
Citation: Osbrink, W.L., Cornelius, M.L., Showler, A., Pound, J.M. 2014. Effects of a Fipronil spot-treatment on field colonies of Coptotermes formosanus (Isoptera: Rhinotermitidae). Journal of Economic Entomology. 107(2):727-740.
Interpretive Summary: The Formosan subterranean termite (Coptotermes formosanus Shiraki) is the most destructive termite where it occurs. Chemical control strategies have failed to protect structures from this termite, costing Americans more than a billion dollars a year in structural damage over most of the continental United States and Hawaii. Fipronil (Termidor, BASF Corp., Research Triangle Park, NC) is a new category of termite control chemical which is non-repellent and slow acting. If a spot treatment resulted in distribution of Fipronil throughout an entire colony of termites causing elimination, its application would save time, money, labor, and client inconvenience. However, this study demonstrated that spot treatments of Fipronil applied to Formosan subterranean termite colonies did not result in distribution throughout the entire colony; distance being a limiting factor in its colony effect. This study indicates that because of the large range and size of the Formosan Subterranean Termite colonies, Fipronil may not be a good candidate for exterior perimeter and localized interior treatment. This study provides pest control professionals the knowledge they need to optimize efficacy of the tools available to them.
Technical Abstract: This field study investigated the colony effect of a Fipronil spot-treatment applied to active infestations of Formosan subterranean termite, Coptotermes formosanus Shiraki. Spot-treatments were applied to a single active independent monitor from each of four colonies in which multiple independent monitors were established. All treated monitors were abandoned and the contents of the treated monitors were replaced with untreated wood at the 30 d post-treatment inspection. All colonies survived their treatment and only one colony exhibited long term effects, which included significant reductions in termite collections and increased worker size. The affected colony was treated within 1 m of its primary nest. Two colonies exhibited significant correlations between termite production and monitor distance from treatment. Distance appears to be factor limiting Fipronil's colony effects. The Formosan termite may not be a good candidate for the exterior perimeter and localized interior treatment label option because of the large range and size of the colony.