Abstract
Polyunsaturated hydrocarbons with a C17-C23 straight chain and the epoxy derivatives constitute a second major class of lepidopteran sex pheromones and are referred to as Type II pheromones. While regionspecific epoxidation proceeds in a pheromone gland, the hydrocarbons are biosynthesized from dietary polyunsaturated fatty acids outside the pheromone gland and transported into the gland after association with lipophorin. In vivo as well as in vitro experiments using Japanese giant looper (Ascotis selenaria cretacea, Geometridae) demonstrated that pheromone biosynthesis-activating neuropeptide (PBAN) accelerated precursor uptake by the gland but not the biosynthetic step, which was contrast with the biosynthesis of Type I pheromones. The neuropeptide of A. s. cretacea, Assc-PBAN, was characterized to clarify its mode of unique action.
