Abstract
The effects of dieldrin emulsion to Sarcophaga peregrina were studied by treating them in larval stage, comparing with that of lindane emulsion. The mortalities of larvae after 24, 48 hours, and those in the total larval stage and in larval and pupal stages, were obtained by treating the 3 rd instar larvae through the rice-husks immersion method, thus obtaining the retarded lethal effect of the chemicals. The lethal efficacy of concentration-mortality regression equation was lower in dieldrin than in that of lindane. The ratio of LC-50 of dieldrin to that of lindance were 1.6 for the larval mortality after 24 hours, 1.9 for after 48 hours, 2.0 for the mortality in total larval stage, and 9.7 for that in larval and pupal stages, so that it was concluded that the retarded lethal effect of dieldrin was higher than that of lindane. It was also recognized that the application of dieldrin or lindane to the larvae would tend to promote their emerging time, though the degree of the promotion was not so remarkable. The number of the flies emerged in the night time was greater than in the daytime, both in the treated and in the untreated by the chemical.
