Effects of filipin and cholesterol on housefly, Musca domestica L., and wax moth, Galleria mellonella L.

Abstract

The effects of filipin on insects are dependent on the molar ratio of cholesterol to filipin. The larvicidal effects of the polyene antibiotic, filipin, can be prevented by excess cholesterol (“excess” herein is defined as a molar ratio of cholesterol to filipin of greater than 2 : 1) in housefly, Musca domestica L., and wax moth, Galleria mellonella L., larvae. Excess cholesterol also prevents the chemosterilant effect of filipin in housefly adults. The filipin-induced inhibition of [ 14C]cholesterol uptake by wax moth larvae is prevented by excess cholesterol; cholesterol uptake is increased severalfold. Dietary filipin, in the absence of added cholesterol, caused loss of 32P from housefly tissues and decreased the incorporation of 32P- and [ 14C]methyl-labeled choline into phospholipids of wax moth tissues. Addition of excess cholesterol to filipin-containing diets enhanced incorporation of 32P into the different classes of phospholipids, and phospholipid synthesis was nearly doubled.