First report of toxicity of<i>Xylopia</i><i>parviflora</i>(A. Rich.) Benth (Annonaceae) root bark's essential oil against cowpea seed bruchid,<i>Callososbruchus maculatus</i>Fabricius (Coleoptera: Chrysomelidae: Bruchinae)

Abstract

The fumigant toxicity of Xylopia parviflora (A. Rich.) Benth (Annonaceae) root bark's essential oil (EO) against cowpea seed bruchid, Callosobruchus maculatus, was investigated in the laboratory. Dose had significant (P < 0.0001) effect on mortality at 6 hours after treatment (HAT) at a concentration of 6.25 μL/mL air which exerted 81.70% mortality, while there was no mortality in all other lower doses. At 12 HAT, 75.05% and 90.00% mortality were observed at doses of 3.15 and 6.25 μL/mL air, respectively. It was significantly (P < 0.05) higher than the mortality (50.58%) observed when 0.78 μL/mL air was applied. The lethal time for 50% of assayed adults (LT50) obtained when the bruchid was exposed to X. parviflora EO at a dose of 6.25 μL/mL air (2.71 h) was significantly lower than LT50 obtained at exposure of bruchid to other lower doses of 0.78-3.15 μL/mL air.