Toxicity of Gamma-Benzene Hexachloride to Preimaginal Stages of the Housefly

Abstract

The results of a study of the toxicity of 7-benzene hexachloride to ova, to 2d- and 3d-instar larvae and to pupae of the housefly, Musca domestica, are reported. Toxicity was detd. by placing test insects either on or between treated paper-toweling discs, in finely-milled softwood sawdust or in an artificial culture medium consisting of crimped oats, alfalfa meal, brewer''s malt, fresh yeast and tap water. 7-Benzene hexachloride is nontoxic to ova, but is strikingly toxic to the other exptl. stages. LD50''s of 3.21, 18.54, and 618 mg./liter were calculated for 2d- and 3d-instar larvae and pupae, and 4.52 and 6.86 mg./liter for 3d instar larvae in synthetic culture and sawdust media, respectively. Some repellency was exhibited toward both larval stages.