The Secretion of the Ventral Glands in Nematus Sawfly Larvae

Abstract Nematine larvae possess ventral glands which contain compounds that protect the larvae from predation. More than 50 volatile compounds have been identified in secretions from the glands of 13 Nematus species. Monoterpenes constitute the major part of the secretion of five species in which long-chain aliphatic compounds (LCAC; C 15–29 ) are also detected. In four other species, short-chain aliphatic compounds (SCAC; C 6–8 ) and aromatic compounds are predominant, LCAC are also present, but monoterpenes are absent. In the four remaining species, the secretion is composed basically of LCAC. The diversity of chemotypes within the genus is discussed.