THE TOXICITY OF HEXANOLIC EXTRACT OF Xylopia aethiopica TO LARVAE OF CULEX P. quiuefasciatus

Abstract

The hexanolic extract of Xylopia aethiopica (Ethiopian pepper) was tested for acute toxicity on the larva of Culex p. quiquefasciatus reared in the laboratory of the Department of Biological Science University of Agriculture Abeokuta, Nigeria. Five concentrations: (50ppm, 100ppm, 200ppm, 300ppm and 400ppm) were evaluated for acute toxicity on the larvae and total percentage mortalities recorded at intervals of 1,12,24,48 and 96 hours in each test. Effects of sunlight and ultra violet radiation on stability of the extract’s potency at 2,4, and 8 hours respectively were equally examined. The mean lethal concentration LC50 was 257ppm. Toxicity of Xylopia aethiopica on Culex p. quiquefasciatus larvae was gradual and persisted throughout the test period. Sunlight exposure has no significant effect on the potency of Xylopia oil while ultra-violet radiation activated its larvicidal properties.