|Su, N - UNIV OF FL IFAS|
|Scheffrahn, R - UNIV OF FL IFAS|
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 1, 1995
Publication Date: N/A
Interpretive Summary: Subterranean termites that damage buildings typically invade through the soil below structures. The most common method to prevent their damage is to pretreat soil with insecticide prior to construction of new buildings or to create a chemical barrier around existing structures. The integrity of these barriers depends on several factors, among them, the thickness and the type of insecticide used. This study determined the most effective combination of insecticide brand, concentration and soil depth that would prevent disruption of this chemical barrier by two subterranean termite species. We found that a barrier created by any product at greater than 100 ppm only 0.15 cm thick was effective at preventing penetration by both termite species. The specific results of many combinations of these factors are presented. Dursban caused much high termite mortality than did the pyrethroid products which act more as termite repellents. These results are important as they describe the precise amount of each product needed to protect structures and thereby reduce the amount of insecticide applied.
Technical Abstract: Penetration of the Formosan subterranean termite, Coptotermes formosanus Shiraki, and eastern subterranean termite, Reticulitermes flavipes (Kollar), into sand treated with 1 of 4 termiticides, Dursban, Biflex, Dragnet, or Prevail, at treatment thicknesses of 0.15 - 5 cm was studied using a laboratory bioassay. Neither termite species penetrated sand containing greater than 100 ppm termiticide, even when the treated barrier was only 0.15 cm thick. Sand treated with 10 ppm Dursban at less than 0.63 cm was breached by both termite species. Sand treated with 10 ppm Dragnet or Biflex was broken through by C. formosanus only when the treatment thickness was 0.15 cm. Prevail at 10 ppm prevented penetration by both termite species. Sand treated with 1 ppm Dursban at thickness of 2.5 cm did not prevent penetration by C. formosanus. Biflex was not penetrated by R. flavipes at any concentration or thickness. C. formosanus broke through the sand treated with 1 ppm Biflex when the treatment was less than 0.63 cm thick. Dursban caused higher mortality than other pyrethroid termiticides.