Mosquito adulticidal activities of crude extracts from above ground part of Laggera pterodonta (D.C) Sch.Bip and Laggera aurita (D.C) Sch.Bip against malaria vector, Anopheles gambiae

Abstract

Mosquitoes are small, midget flies that transmit harmful infections such as malaria, yellow fever, and dengue fever in Nigeria. Its control using a synthetic insecticide is becoming increasingly difficult due to high cost, persistence in the environment, and development of resistance by the mosquitoes. The aim of this study is to evaluate the adulticidal activity of crude ethanolic extract of the above ground parts of Laggera pterodonta and Laggera aurita against adult Anopheles gambiae. Dried Laggera pterodonta and Laggera aurita were individually macerated with 70% ethanol to obtain the crude extract. Phytochemical screening revealed the presence of saponin, flavonoids and terpenoids in both Laggera pterodonta and Laggera aurita while tanins and alkaloids were present in Laggera aurita only. The extracts were tested against 4-5 days old laboratory-reared adult Anopheles gambiae. The findings revealed that the adulticidal lethal concentration LC50 of L. pterodonta crude extract was 4553 mg/L while the LC50 of L. aurita was 5582 mg/L. The result suggests the extracts are potential natural insecticides against adult An. gambiae mosquitoes.