The Differences Between Male and Female American Roaches in Total Lipid Content and in Susceptibility to DDT

Abstract

In Periplaneta americana the total lipid content is highest (6.8% of wet wt.) in large nymphs, but falls rapidly during the 1st half week of adult life and therafter declines slowly. Females (nymphal or adult) exceed males of the same age in quantity of total lipids by a small amt. The resistance of roaches to DDT shows a high correlation with their lipid content; but there seems to be an additional difference in resistance of the 2 sexes not accounted for by their difference in lipid content.