Larvicidal Effects of Three Plant Ethanolic Extracts against Culex quinquefasciatus SAY. Larvae (Diptera: Culicidae)

Abstract

Laboratory experiments were conducted to evaluate the
larvicidal activity of ethanol extracts from the leaves of three plant
species: Ricinus communis L. (castor plant), Vinca rosea L. (vinca) and
Lantana camara L. (lantana). Each of three extracts was used at five
rates; namely, 250, 500, 1000, 2000 and 3000 ppm, against the 3rd instar
larvae of Culex quinquefasciatus SAY. Larval mortality percentages were
recorded 24 hours after treatment. The larvicidal effect of each extract
was compared with the standard larvicide temephos (Abate® ). The three
tested extracts showed larvicidal effects at all rates. Castor extract had the
greatest larvicidal effect with the lowest LC 50 (323.0 ppm), followed by
vinca and lantana extracts. These results suggest that the leaf extracts of
the three plant species should be considered as promising larvicides
against Cx. quinquefasciatus larvae