Termiticidal Effect of Methanol Extract of Deguelia utilis (A.C.Sm.) A.M.G. Azevedo Vine (Fabaceae) on Macrotermes bellicosus

Termites, particularly Macrotermes bellicosus, are major pests of agricultural and structural resources in sub-Saharan Africa, causing significant economic losses. Conventional synthetic termiticides are effective but are associated with environmental hazards and the development of resistance, creating a need for safer botanical alternatives. This study evaluated the termiticidal activity of methanol extracts of Deguelia utilis (A.C. Sm.) A.M.G. Azevedo vine (Fabaceae) against worker and soldier castes of M. bellicosus. Vine samples of D. utilis were collected, shade-dried, pulverized, and macerated in methanol. Serial dilutions (10–80 mg/mL) of the extract were prepared, and 20 μL of each concentration was topically applied to groups of ten termites per caste. A 2% Solignum solution served as the positive control. Mortality was recorded over hours. Data were analyzed using one-way ANOVA followed by Dunnett’s post hoc test, with significance set at p < 0.05. The extract exhibited dose- and time-dependent termiticidal effects in both castes. In worker termites, 10 mg/mL caused 33.33 ± 12.00% mortality at 0.5 h, increasing to 56.67 ± 26.00% at 2.5 h. At 80 mg/mL, mortality reached 100% within 2.5 h, comparable to the control. Soldier termites showed slightly lower susceptibility at lower concentrations, with 13.33 ± 3.33% mortality at 10 mg/mL (0.5 h) and 46.67 ± 3.33% at 2.5 h, but 80 mg/mL induced 100% mortality by 2.5 h. The methanol extract of D. utilis vine demonstrates potent concentration- and time-dependent toxicity against M. bellicosus, indicating its potential as a natural alternative to synthetic termiticides in sustainable pest management strategies. Keywords: Deguelia utilis, methanol extract, Macrotermes bellicosus, termiticidal effect, botanical pesticide, Fabaceae, subterranean termites [PDF Full Text]