Full Length Research Paper

Toxicity, growth regulatory and repellent activities of medicinal plant extracts on Musca domestica L. (Diptera: Muscidea)

Hervé B. D. Bisseleua^1,2*, Seth W. K. Gbewonyo³, Daniel Obeng-Ofori⁴

¹Laboratory of Entomology, IRAD, P.O. Box 2067, Yaoundé, Cameroon.

²Department of Crop Sciences, Entomological Section, Grisebachstr. 6 37077 Goettingen Germany.

³Department of Biochemistry, University of Ghana, P.O. Box 52 Legon Accra.

⁴Crop Sciences Department, University of Ghana, P.O. Box 82 Legon Accra.

*Corresponding author. E-mail: hbissel@gwdg.de.  Tel: +49551 39 22010.  Fax: +49 551 39 12 105.

Accepted 8 September, 2008

Housefly, Musca domestica, is a major vector for many medical and veterinary pathogenic organisms. The development of naturally occurring insecticides, represent one of the most promising approaches for their ecochemical control. Petroleum-ether extracts of Griffonia simplicifolia and Zanthoxylum xanthoxyloides were assessed for their toxicity, growth regulatory and repellency to the housefly. Percent mortality and index of repellency induced by the extracts against the insects were found to be dose-dependent. Seed extracts of G. simplicifolia and root extracts of Z. xanthoxyloides were the most effective as toxicants and repellents against the fly. The LD₅₀ in 24 h topical application of seed extracts of G. simplicifolia and root extracts of Z. xanthoxyloides were 0.28 and 0.35 µg, respectively. Seed extracts of G. simplicifolia evoked a very strong regulatory effect against the second larval instar of the housefly. The RD₅₀ of crude extracts of G. simplicifolia and Z. xanthoxyloides against housefly ranged from 1.0 to 6.8 and 1.3 to 1.7 µg cm^–2, respectively. Extracts of the two plant species may be useful as insecticides for controlling the housefly and should be exploited as a component of integrated vector control strategies or could be useful in the search of new larvicidal natural compounds.

Key words: Botanical insecticides, crude extracts, integrated vector management, larval growth inhibitor.