Chemical Ecology, Göteborg University, Box 461, 40530 Göteborg, Sweden.
In collaboration with colleagues in Lund and Sundsvall, Sweden, and in Finland, Poland, Germany, France and Italy, we have studied the sex pheromones of pine sawflies from a comparative evolutionary point of view and as a prerequisite for controlling these forest pest insects by monitoring. This has been done first as a collaboration between groups in Sweden, then as a collaborative EU project: "PHERODIP" during the time period 1996-1998. The work is now continued further. An earlier report with the emphasis on our analytical-chemical efforts was given at the ISCE Syracuse meeting five years ago. The present contribution concentrates on work done since then. We have found that in 8 species of pine sawflies (fam. Diprionidae), viz. Neodiprion sertifer, Diprion pini, Diprion similis, Microdiprion pallipes, Macrodiprion nemoralis, and three species of Gilpinia the active pheromones are esters - acetates and/or proprionates - of straight long chain secondary alcohols with one, two or three methyl groups in different positions (3, 7, 9, 11). It means that there are, respectively, 4, 8 or 16 stereoisomers for which the absolute configuration has to be determined. The compounds occur at the 1 ng level (per female). The work calls for very sensitive, well-separating and informative analytical methods, involving derivatives, for studies of single individuals.A final goal of this work, apart from the applied aspects, is to compare the pheromones of the different species in an evolutionary perspective. Preliminary studies of the site of production of pheromone precursor and its esterification have been made.