Growth-inhibiting and larvicidal effects of Melia volkensii extracts on Aedes aegypti larvae

Abstract

Extracts from dry Melia volkensii fruits contain growth-inhibiting activity against larvae of the mosquito Aedes aegypti. The active fraction may be eluted from silica gel using hexane-ethyl acetate (1:1, v:v). At a concentration of even 2 μg/ml in water, this fraction prolongs larval instars. Mortality in treated larvae is high, especially during the moulting and melanisation processes. The LC50 for larval mortality is 50 μg/ml in 48 h. The active compound of this fraction is not identical with azadirachtin. It may be more potent as an insect growth-inhibitor and more lethal to Aedes larvae than azadirachtin