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

Abstract

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.

Film seeds coating with hexane extracts from Illicium verum Hook.f. and Syzygium aromaticum (L.) Merrill & Perry for controlling Callosobruchus maculatus (F.) and Callosobruchus chinensis L

“…Many reports have used essential oils or crude extracts of some plants to control stored product insect pests such as the botanical extracts of neem, nochi, eucalyptus, annona and garlic against the bruchid beetle on stored grains 17 . The essential oils of star anise and dill presented the highest repellency and ovipositional inhibition against red flour beetles and saw‐tooth grain beetle 18 .…”