Larvicidal and adult emergence inhibition activity of Abutilon indicum (Linn.) (Malvaceae) leaf extracts against vector mosquitoes (Diptera: Culicidae)

The crude leaf extracts of Abutilon indicum were evaluated for larvicidal, pupal deformities and adult emergence inhibition activity against vector mosquitoes viz., Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus. Larvicidal activity was carried out using WHO protocol. Hexane extract with LC50 value of 261.31 ppm after a period of 24 hr was found to be effective against Aedes aegypti larvae. Larval and pupal development was arrested resulting in decreased pupal transformation and adult emergence. Larval and pupal periods were prolonged with appearance of larval–pupal and pupal–adult intermediates, with an overall increase in the developmental period. Hatching was delayed and its rate was reduced compared to control. Disrupted egg shells and dechitinized body walls were observed, indicating clearly the anti-juvenile potential of the extract. The growth index was considerably reduced. These results suggest the leaf extracts of Abutilon indicum as a promising adult emergence inhibitor against vector mosquitoes and might be used in small volume aquatic habitats or breeding sites of limited size in and around human dwellings.