Natural durability of some selected wood species against Macrotermes sybhylinus termites

Abstract

Natural resistance of some wood species used consistently for construction in Nigerian to termite was examined in this study. Wood samples were collected from a Sawmill in Akure and cut to stakes of 35 × 35 × 450 mm which were to be buried half way in the soil, their density was determined and classified across three density classes; high, medium and low. They were exposed to subterranean termites attack for 12 weeks (3 months) in a timber graveyard. Weekly visual estimation of the stakes was done in accordance with ASTM D 3345/1980 rating scale and gravimetric weight loss assessment was carried out after 12 weeks of exposure. Results showed that there was significant difference (p<0.05) in the resistance of the species to Macroterms sybhylinus, a native of subterranean termite, identified on the site. It was discovered that there is a strong negative correlation between weight loss and wood density, which implied that species in higher density classes exhibited greater resistance to termite attack after the exposure period. Other factors such as presence of toxic extractives and age could also be responsible for higher resistance. This study proved the importance of wood protection for all wood species irrespective of wood density class using appropriate technologies to ensure a longer service life. It reduces cost of wood replacement and sustainable management of our forest resources.