Evaluation of botanical extracts against Callosobruchus maculatus F. (Coleoptera: Chrysomelidae) on different host grains

As the damage of stored legume grains by Callosobruchus maculatusis severe in Sri Lanka, the present study was conducted to find the remedial solution for this existing problem. The experiment was designed to select the most effective botanical insecticides; Azadirachta indica 10 %, Vitex negundo10 %, Eucalyptus globulus10 %, Annona squamosal 10 % and Allium sativum 10 % against the insect pest, Callosobruchus maculatus (bruchid beetle) on stored grains; Vigna unguiculata var. Waruni (red cowpea), Vigna unguiculata var. Dhawala (cowpea with black eye), Vigna radiate (green gram) and Cicer arietinum (chickpea). Among these treatments, A. indica 10 % and A. sativum 10 % were found to be the significantly best along with 80 % of mortality in adult weevils and zero damaged seeds in all treated grains whereas V. negundo 10 % and E. globulus 10 % had average mortality effect (40-50 %) at the beginning of the study. Apart from this zero seed, damage was observed in chickpea treated with all treatments including untreated control. The study showed the non-preference of chickpea by C. maculatus as the seed coating was resistant to the beetle attack.