Evaluation of Tung Oil (Vernicia fordii (Hemsl.)) for Controlling Termites

Abstract
In worldwide, the use of chemical pesticides to protect wood has been greatly restricted. In recent years, a large number of researchers devoted to the search for natural, safe and non-polluting bioactive chemical compounds from plants as an alternative to synthetic organic chemical preservative. In Chinese folk, tung oil can be used as paint for wooden furniture to protect them from pests. This study aimed to evaluate the chemical compositions of raw and heated tung oil and their activity against termite. In choice bioassays, weight loss of wood treated with 5% raw or heated tung oil after 4 weeks was significantly less than that of the control group. In no-choice bioassays, there was a significant difference in termite survival and wood weight loss on raw and heated tung oil-treated wood. When tung oil-treatment concentrations increased to 5%, wood weight loss was less than 10%. There was no significant difference in termite survival and wood weight loss between raw and heated tung oil-treated wood. Survival of termites in both tung oil wood treatments was significantly lower than that in the starvation control after 4 weeks. Raw and heated tung oil significantly improved the resistance of pine wood to termites, and have the potential for the development of natural wood preservatives.