Mosquito Larvicidal Activity of Mangrove Plant Extracts and Synergistic Activity of Rhizophora apiculata with Pyrethrum against Culex quinquefasciatus

Abstract

Plant samples were collected from 15 mangrove species, Acanthus ilicifolius, Aegiceras corniculatum, Avicennia marina. A. officinalis, Bruguiera cylindrica, Ceriops decandra, Excoecaria agallocha, Rhizophora apiculata, R. Lamarckii, R. mucronata, Salicornia brachiata, Sesuvium portulacastrum, Sonneratia apetala, Suaeda maritima, S. monoica and Xylocarpus granatum. The 22 samples were extracted in acetone and petroleum ether separately, and the extracts were tested for their activity against the larvae of mosquito, Culex quinquefasciatus. Petroleum ether extract of R. apiculata was found most effective with LC 50 of 25.7 mg/l. The extract was studied further with pyrethrum for its synergistic larvicidal activity. The extract exhibited synergism and the synergistic factor was 0.81 at 5 mg/l.