AGGREGATION PHEROMONE OF PITYOKTEINES ELEGANS

In laboratory bioassay experiments, the beetles Pityokteines elegans w ere attracted to volatiles captured from bolts of grand fir, Abies gra ndis, colonized by P. elegans males. Male-specific volatiles detected by coupled gas chromatographic-electroantennographic detection (GC-EAD ) analysis and by CC-mass spectrometry employing a chiral column were: (S)-(-)-ipsenol, (+)- and (-)-ipsdienol, and ipsenone. Field experime nts demonstrated that 1:1 combinations of (-)-ipsenol and (+/-)-ipsdie nol strongly attracted insects of both sexes to multiple-funnel traps. No beetles were attracted to any of these compounds alone, and both e nantiomers of ipsdienol were required with (-)-ipsenol to induce attra ction. Ipsenol and ipsdienol are now reported as pheromones of five Pi tyokteines species. Specificity of semiochemical-based communication b etween sympatric P. elegans and P. minutus appears to be based on host preference and on the composition and chirality of the pheromone blen d.