Termite-resistant heartwood. Effect of antioxidants on termite feeding deterrence and mortality

Biocides currently employed to prevent termite damage face environmental and toxicity concerns. We recently proposed that heartwood which is naturally resistant to termites might be due to the extractives having both toxicity and antioxidant properties and we reported that the artificial and benign antioxidant butylated hydroxytoluene (BHT) had termite feeding deterrence and toxicity properties. Here, we investigate other antioxidants, both natural and synthetic, and analogs which lack antioxidant properties, on Reticulitermes flavipes Kollar. Laboratory no-choice tests according to AWPA Standard E1 were performed. Antioxidants that are benign to humans had feeding deterrence and mortality properties to R. flavipes. Conversely, the non-antioxidant analogs, with the exception of the heterocyclic flavanone which was previously shown to be active against decay fungi, had little effect on R. flavipes. We conclude that R. flavipes avoids wood which contain high levels of antioxidants, such as heartwood with phenolic extractives.