Insecticidal Activity Of The Leaf Extract Of Hyptis Spicigera Against Callosobruchus Maculatus On Grainsharvested In Zaria, Northern Nigeria

The insecticidal properties of H.spicigera leaf extracts (hexane, ethylacetate and methanol) tested against Callosobruchus maculatus on cowpea was carried out using Azadirachtin as a standard. Ethylacetate extract and standard azadirachtin showed the highest percentage mortality of 98% each at 72hr, while methanol, hexane and control gave percentage mortality of 75%,87% and 21% respectively. Percentage emergence of Azadirachtin standard and ethylacetate extract showed 6% and 8% while methanol, hexane and control gave percentages emergence of 18%,13% and 87% at 72hr respectively. Ethylacetate and methanol extracts showed oviposition deterrent at 3.16% and 5.56% while hexane, and control gave 11.11%, and 76.39% respectively. These results showed that ethylacetate and methanol extracts were active in controlling C.maculatus eggs laid relative to azadirachtin (2.78%) used as standard in this study. At 16wk, hexane extract showed the least percentage (2%) seed damaged while ethylacetate, methanol and control gave 5%, 23%,88% relative to standard azadirachtin (10%).The data showed ethylacetate leaf extract of H. spicigera with 3.16% oviposition deterrent,98% mortality and 6% emergences having potentials for use as a bio-control agent in post- harvest storage on grains susceptible to insect attack/infestation than methanol and hexane extracts.