• 2020-11-10
• Amulejoye F.D
• Volume 2, Issue 2

Abstract

The larvicidal activity of Dermestes maculatus larvae by the oils of Allium sativum (Garlic), Cocos nucifera (Coconut), Zingiber officinale (Ginger), Jatropha curcas (Jatropha) and Azadirachta indica (Neem) was evaluated. Late instar larvae of D. maculatus were introduced into Kilner jars containing fish treated with these oils, whose physicochemical properties and the fatty acid compositions had been previously determined. Untreated fish were also placed in jars to serve as control. Results showed that the oils caused significant mortality (P<0.05) on the larvae of D. maculatus in treated fish compared to the untreated fish at 96h after infestation. 100% mortality was recorded for all the oils at the highest concentration by the 96th hour of exposure. The fatty acids detected in the oils were: oleic acid (in J. curcas and A. indica); octadecanoic acid (in Z. officinale and C. nucifera); stearic and palmitic acids (in A. indica and C. nucifera); lauric, linoleic and myristic acids (in C. nucifera); octadecanoic acid (in J. curcas) and cyclopropanepentanoic acid (in Z. officinale). The larvicidal potential of the oils in offering effective protection against infestation and damage by D. maculatus have been clearly demonstrated in this study; the oils are therefore recommended for utilization in post-harvest preservation of smoke-dried fish.