Effects of steroid metabolism inhibitors and ecdysteroid analogs on honey bee sterol metabolism and development

Abstract

AbstractThe effects of two azasteroids, an alkyl amine, and two ecdysteroid analogs on honey bee (Apis mellifera L.) sterol metabolism and development were compared by feeding each compound in a chemically defined diet supplemented with 24‐methylenecholesterol. Although each of the inhibitors, 25‐azacoprostane, 25‐azacholestane, or N,N‐dimethyldodecanamine, has been shown to severely inhibit steroid metabolism and larval development in a number of species of omnivorous and phytophagous insects, none of them affected honey bee brood development to the adult stage. Compared to the controls, there was a strikingly higher relative percentage of 24‐methylenecholesterol in the sterols from prepupae reared by workers fed diets containing each of these inhibitors, but the level of this sterol was reduced considerably in the adults reared from the brood in these test colonies. Each of the ecdysteroid analogs, 22,25‐dideoxyecdysone or 2,22,25‐trideoxy‐5β‐hydroxyecdysone, severely suppressed larval development when fed in the chemically defined diet. This effect apparently results from the presence of the dietary ecdysteroid or its metabolite in the brood food placed in the larval cells or the inability of the worker bees fed the ecdysteroid to include some essential factor in the brood food. The importance of this information relative to the possible application of certain steroid inhibitors to control pathogens of honey bees is discussed.