Guntharee Sripongpun

pp. 667 - 672

Abstract

Contact toxicity of the ethanol crude extract of Chinese star anise fruits, Illicium verum Hook. F. (Illiciaceae) to house fly larvae, Musca domestica L. (Diptera: Muscidae) and their development were determined by a dipping method. Younger larvae were more susceptible than older. The median lethal concentration (LC₅₀) values of the crude extract to the 2^nd instar larvae at 24, 48 and 72 hours were 7.4x10⁴, 4.1x10⁴ and 3.2x10⁴ mg/l, respectively. Furthermore, treated extracts affected house fly development in pupal and adult stages. The number of test larvae developed to pupae and adults was less
than that of control group. The crude extract at concentration 8.5x10⁴ mg/l completely inhibited development from larvae to pupae. In addition, small pupae were found at every concentration between 2.5x10³ -105x10³ mg/l. Small treated pupae were observed more at higher concentrations. Some of them could continually develop to adults but their developmental percentages were less than those of normal sized pupae in treatments and in control group. The crude extract of Chinese star anise fruits can be applied as an optional point source control of house fly.