LAUSR

Certain elements and compounds of biological importance are sequestered by many pesticidal plants, and are of global interest for wood protection. While manifold studies have demonstrated the protective properties of these elements and compounds, little is known about Spondiathus preussii (SP) biological activity and its closely related responsible chemicals. In this study, the leaf extract (LE) and stem bark extract (SBE) from SP, an ethnomedicinal plant reputed as rodenticidal agent in Nigeria were investigated to ascertain their termiticidal effects on Vitex doniana wood. Total contents of toxic elements (Al, As, B, Cd, Cr, Cl−, Cu, Hg, I, Pb, Si and Zn) and compounds (alkaloids, flavonoids, phenol, saponins and tannins) of wood protection concerns were measured in LE and SBE of SP. Four extracts’ concentrations of SP LE and SBE in 1 L of 50% ethanol, including solvent alone (0%) and water (control) were developed to treat V. doniana wood samples. Extracts treated wood samples were evaluated for the levels of field termiticidal effects after 4 months using visual rating and weight loss techniques. Extract yields of leaf (1.66 ± 0.02%, n = 2) and stem bark (1.84 ± 0.08, n = 2) were significantly not different. Concentrations of all the metals and compounds were significantly higher in leaf compared to those in stem bark. Both LE and SBE showed better significant acceptable wood protection profile at 20% concentration. In all, LE remarkably exhibited higher differential termiticidal effects than those of SBE. These findings support further wide scope study on the biological activity of SP grown under varying ecological conditions in Nigeria against wood pests, and development of SP-based biocides for wood treatment.