Entomology, Ornithology & Herpetology: Current Research
Open Access

Abstract

The Herbal Insecticides from Root Stock of Alocasia indica as Potential Sources for Control of Stored-Product Insect Pests

Yallappa Rajashekar and Ngaihlun Tonsing

In the present study the insecticidal activity of organic extracts from root stock of Alocasia indica (Linn.) against three major important stored grain insect pest viz; rice weevil, Sitophilus oryzae; the lesser grain borer, Rhyzopertha dominica and the rust-red flour beetle, Tribolium castaneum is reported. The fumigant toxicity of hexane extract shows LC50 value 108.4 μg/l for adult T. castaneum, 96.2 μg/l for S. oryzae and 84.6 μg/l for R. dominica, respectively and toxicity was species specific. A concentration of 300 μg/l for a period of 72 h exposure resulted in 100% mortality of mixed age culture of these three species. An extended exposure period of 72 h has increased the rate of mortality in all three species. Further the results confirm that there are no significant differences between seed germination of control and treated grains. The study proved that efficacy of Alocasia indica when extracted with hexane is more effective when compared with other type of solvent extractions. The probable use of this extract as a bio fumigant is here with discussed.