Larvicidal activity of Nerium oleander L. (Apocynaceae) flower extracts against Culex quinquefasciatus Say (Diptera: Culicidae)

摘要

Culex quinquefasciatus is the vector responsible for serious disease filariasis among human beings.Plant derived products have received increased attention from scientists as they serve as a rich sourcefor novel natural substances possessing insecticidal properties which are safe to human andecosystem. During the last decade, various studies on natural plant products against vector mosquitoindicate them as possible alternatives to chemical and synthetic insecticides for mosquito control. Inthe present study, the crude hexane and aqueous extract of Nerium oleander flowers were reportedfor larvicidal activity against the filarial vector, Culex quinquefasciatus. Mortality was observed for24 and 48 hours. Hexane flower extract exhibited highest larvicidal activity with a LC50 value of102.54 ppm and 61.11ppm after 24 and 48 hours respectively. Further investigations are needed toelucidate this activity against a wide range of all stages of mosquito species and also the activeingredient(s) of the extract responsible for larvicidal activity should be identified.