Larvicidal and ovicidal activity of Retz. (Family: Combretaceae) medicinal plant extracts against , and .

Insect-borne diseases remain to this day a major source of illness and death worldwide. The resistance to chemical insecticides among mosquito species has been considered as a setback in vector control. Mosquito control programs, botanical origin may have the potential to eliminate eggs and larvae. So, the larvicidal and ovicidal activities of crude benzene, hexane, ethyl acetate, chloroform and methanol extracts of were assayed for their toxicity against three important vector mosquitoes, viz., , , and The larval mortality was observed after 24 h of exposure. All extracts showed moderate larvicidal effects; however, the highest larval mortality was found in the methanol extract of against the larvae of , , and with the LC values were 87.13, 93.24 and 111.98 ppm, respectively. Mean percent hatchability of the ovicidal activity was observed 48 h post treatment. The percent hatchability was inversely proportional to the concentration of extract and directly proportional to the eggs. All the five solvent extracts showed moderate ovicidal activity; however, the maximum egg mortality (zero hatchability) was observed in the methanol extract of at 200 and 250 ppm against , and showed 100% mortality at 300 ppm. No mortality was recorded in the control. The finding of the present investigation revealed that the leaf extract of possesses remarkable larvicidal and ovicidal activity against medically important vector mosquitoes and make this plant product promising as an alternative to synthetic insecticide in mosquito control programs.