The cowpea weevil, Callosobruchus maculatus
(F.), is a major pest of cowpea ( Vigna unguiculata
(L.) Walp.) in storage. A laboratory study was conducted to investigate the inhibition potential of Guiera senegalensis
galls on C. maculatus
detoxification enzymes. Methanol extract from galls of G. senegalensis
exhibited strong inhibitory effects of the activity of C. maculatus
acetylcholinesterase (AChE) and mixed-functional oxidase enzymes. The chemical composition of the extracted oils was examined by gas chromatograph (GC)-flame ionisation detectors (FID) and mass spectrometry. Twelve components were identified, namely 2-Hydroxy-4-methoxybenzophenone, n-Pentadecane, Octadecane, 1,2-Benzenedicarboxylic acid, dibutyl ester, Palmitic Acid, Hexadecane, Cis-vaccenic acid, Oleyl alcohol, stenol, n-Eicosane, n-Heneicosane and vincubine. This plant could be used for improving the efficacy to various insecticide classes against C. maculatus
and as an alternative to synthetic insecticides.