Evaluation of Anti-termitic Properties of Nigerian-Grown Eucalyptus camaldulensis for the Treatment of Selected Susceptible Timbers

Abstract

This study addresses the protection of Nigerian-grown lower-class timbers (Afara-N6, Abura-N4, Ayure-N5, Mahogany-N5, and Obeche-N6) according to the Nigerian NCP2 classification. Subterranean termites, particularly Coptotermes formosanus, are recognized as significant destroyers of timber and timber products in tropical regions. To combat this, higher-class (N1) Nigerian-grown Eucalyptus camaldulensis timber was utilized to develop non-synthetic anti-termite extracts for treating the susceptible lower-class timbers. These extracts offer advantages over synthetic chemicals by minimizing harm to non-targeted organisms in the ecosystem. Phytochemical analysis revealed significant concentrations of tannin (0.440mg/100g), phenol (0.402mg/100g), saponin (0.208mg/100g), flavonoids (0.025mg/100g) and alkaloids (0.024mg/100g) in the aqueous solution extracts. Graveyard tests, conducted according to ASTM D 1758-74, demonstrated effective treatment of Ayure, Abura, and Mahogany, with minimal percentage weight loss of 0.08, 0.31, and 0.48 respectively. However, Obeche and Afara exhibited higher percentage relative weight loss of 1.05 and 9.05 respectively, possibly due to the absence of phlobatannins and hydroxyl anthraquinone phytochemicals in the extracts. Overall, the Eucalyptus camaldulensis extract shows promise in significantly reducing termite damage in Nigerian-grown timbers such as Ayure, Abura, and Mahogany.