Evaluation of the Resistance of Gmelina arborea Wood Treated With Creosote Oil and Liquid Cashew Nut Shell to Subterranean Termites' Attack

This study examined the resistance of Creosote oil (CREO) and Cashew nut shell liquid (CNSL) on theprotection of Gmelina arborea wood against subterranean termites’ attack. Gmelina wooden stakes weretreated with undiluted CREO and with diluted CREO/ kerosene mixtures ratio 1:1 and 1:3; undiluted CNSLand diluted CNSL/kerosene mixtures ratio 1:1 and 1:3, using cold dipping method. Termites’ field exposuretest was carried out at the timber grave yard for 36 months (3 years) to test the resistance of CREO andCNSL preservatives to subterranean termites. Weekly visual observations according to American Standardsfor Testing Materials (ASTM) were taken to find out the effect of prolonged exposure of treated woodsamples to termites’ attack. CREO treated samples had 54.2, 65.0 and 76.0% weight loss compared to thecontrol (untreated) sample having 86.7% respectively for the same period. CNSL treated samples had 80.0,80.8 and 85.0% weight loss respectively compared with the control with 86.7%. These results indicated thatCREO treated samples provided a better protection against subterranean termites compared with CNSLtreated samples for the 36-month period.