Analysis of the Labial Gland Secretion of the Cuckoo-Bumblebee (Psithyrus vestalis) Males and Synthesis of Abundant Geranylcitronellol

Labial glands of the cuckoo-bumblebee males of the species Psithyrus vestalis were extracted and the components of their secretions were identified. Chemical composition of the males' signal of Psithyrus vestalis has not yet been described in the literature. We found geranycitronellyl acetate to be the main component (48%). Geranylcitronellol and (Z)-15-eicosen-1-ol were present in the secretion in lower amounts. Long-chain aldehydes, acetates, and hydrocarbons formed only minor components of the mixture. The identification of minor components was based on GC-MS, while the more abundant compounds were isolated and fully characterized by spectral and chemical methods. For the structure confirmation, geranylcitronellol was prepared from geranyl bromide via a three-step synthesis.