Chemistry of male mandibular gland secretions of Philanthus triangulum

Males of the European and African beewolf, Philanthus triangulum, possess a sex specific mandibular gland secretion that is used for marking plant stems in mating territories. The secretion is composed of 90% (Z)-11-eicosen-1-ol plus small amounts of 10-nonadecen-2-one, nonadecenal, octadecanoic and octadecenoic acids, and eicosenal, The chemistry of this secretion differs markedly from the secretions of North American Philanthus, which consist of a larger number of components that possess differ ent chemical functionalities and are more volatile. We postulate that the chemical differences between P. triangulum and its New World relatives reflect phylogenetic differences plus a possible reduced necessity for species isolating mechanisms in P. triangulum