Toxicity and Feeding Deterrent Effect of 2-Methylanthraquinone from the Wood Extractives of Tectona grandis on the Subterranean Termites Coptotermes formosanus and Reticulitermes speratus

Abstract

No-choice feeding tests using ethanol, chloroform, and acetone extractives of teak (<i>Tectona grandis</i>) heartwood clearly showed feeding deterrent activity and toxicity to the subterranean termite <i>Reticulitermes speratus</i>. The amount of 2-methylanthraquinone (MAQ) in teak wood extractives was not related to the feeding deterrents or toxicity, as shown by the no-choice feeding tests conducted using crude extractives containing various amounts of MAQ, MAQ alone, and fractions of crude extractives. As a native pest, the subterranean termite <i>Coptotermes formosanus</i> was more tolerant to the fractions of crude extractives than <i>Reticulitermes speratus</i>, and the mortality observed in <i>C. formosanus</i> was not due to the presence of MAQ.