Effects of nootkatone on behavior and physiology of Coptotermes formosanus. New Orleans, Louisiana, USA, May 13-15 2001.

Nootkatone, one of over 300 components of vetiver oil, is a mildly pungent sesquiterpene ketone with a distinctive grapefruit flavor, largely responsible for vetiver oil unique aroma. As part of our research on natural products efficacy against Formosan subterranean termite, previous experiments suggested that vetiver oil and some of its components acted as a repellant and toxicant to this pest. In order to better understand how nootkatone affects the behavior and physiology of these termites. Treatments consisted in: Sand treated with nootkatone and both slices of non-treated wood; Non-treated sand and both slices of nootkatone-treated wood; Non-treated sand, one slice of nootkatone-treated wood and one slice of non-treated wood; Control with non-treated sand and both slices of non-treated wood. Daily observations on the number of feeding termites on each wood slice, evaluations of tunneling behavior, weekly measurements of food consumption, variation in the number of different species of symbiont protozoa present over time and termite survival were recorded. Our results showed that exposure to nootkatone disrupt normal termite behavior, significantly affecting feeding ability and survival. Effects on the protozoa suggest that nootkatone may also act directly as a toxicant. For its negative effects on termite physiology and behavior, nootkatone may represent a promising natural alternative for termite control.