Potential for Melia volkensii fruit extract in the control of locusts

Abstract

Fruits from the East African tree, Melia volkensii (Gurke) contain terpenoid compounds with well-establishcd insecticidal activity. At high doses a concentrated M. volkensii extract (Mv) causes death or lack of physical fitness in locusts by irreversible paralysis of the locust skeletal muscles, without affecting the malpighian tubules or the pulsation of the dorsal heart. This effect is temperature related, with lower doses becoming more effective as the temperature increases. This action favours Mv toxicity against locusts in hot desert areas. Mammalian toxicological studies showed that Mv does not present any acute or chronic toxicity effects when orally administered to laboratory mice. It was thus not possible to establish an oral LD50 for the product in mice. Mv production in bulk and shelf-life are discussed with a view to demonstrating its advantages as a possible locust control product.