Mosquito larvicidal, pupicidal and ovicidal effects of the extracts of Peltophorum pterocarpum flowers on Aedes aegypti and Culex quinquefasciatus.

Mosquitoes are the vectors of several diseases like dengue, chikungunya, malaria etc. The three important mosquito species in India are Aedes aegypti, Culex quinquefasciatus and Anopheles stephensi. Several plant extracts have been tested for their anti-mosquito activity. In this dissertation, the larvicidal, pupicidal and ovicidal activities of the successive hexane, chloroform and methanol extracts of Peltophorum pterocarpum (Fabaceae) on mosquitoes are reported. The larvicidal activity of those extracts on both Aedes aegypti and Culex quinquefasciatus mosquitoes was found to be in a decreasing order of hexane, methanol and chloroform - the LC50 values for these extracts were 111.81 and 104.84 ppm, 121.92 and 121.56 ppm, 357.2 and 352.0 ppm respectively. Their pupicidal activity on both mosquitoes was found in the order of methanol, chloroform and hexane - the LC50 values for these extracts being 172.8 and 162.35 ppm, 425.8 respectively. Their ovicidal activity on both mosquitoes was found to be very low, even at the higher concentration of 500 ppm. This is the first report on the effect of the extracts of Peltophorum pterocarpum flowers on the two mosquito species of Aedes aegypti, Culex quinquefasciatus. In the present work, the results showed that the hexane extract had the highest larvicidal activity, while methanol showed the highest pupicidal activity besides larvicidal activity. Hence, the methanol extract holds promise to be used as mosquitocidal agent against the above two vectors.