Svoboda, J.A., Insect Physiology Laboratory, Beltsville, 20705, Maryland, United States
Thompson, M.J., Insect Physiology Laboratory, Beltsville, 20705, Maryland, United States
Elden, T.C., Applied Plant Genetics Laboratory, Beltsville, 20705, Maryland, United States
Robbins, W.E., Insect Physiology Laboratory, Beltsville, 20705, Maryland, United States

Three saturated sterols, cholestanol, campestanol, and stigmastanol, constituted 54, 72, and 77% of the total sterols of the egg, prepupa, and adult, respectively, of the Mexican bean beetle, Epilachna varivestis (Mulsant), reared on soybean plants. Lathosterol (7-cholesten-3β-ol), possibly formed from cholestanol in this insect, constituted 12, 16, and 11.8% of the total sterols isolated from egg, prepupa, and adult, respectively. None of these sterols have been isolated and identified previously as components of the sterols of a phytophagous insect reared on a natural host plant. Cholesterol, a major sterol of most plant feeding insects studied thus far, comprised less than 5% of the total sterols in any of the stages examined. The unique composition of the sterols in this insect in relation to the sterol composition of the host plant is compared to dietary sterol utilization and metabolism in other phytophagous insects. © 1974 American Oil Chemists' Society.