Sex-specific production of ipsdienol and myrcenol byDendroctonus ponderosae (Coleoptera: Scolytidae) exposed to myrcene vapors.

Male mountain pine beetles,Dendroctonus ponderosae Hopkins, produced ipsdienol [97.0% ± 0.3S-(+)] and myrcenol (90.3% ± 4.0E) when exposed to myrcene vapors. Females which were exposed to myrcene vapors did not produce any ipsdienol, but did produce low levels of myrcenol (98.0% ± 0.7E). Neither sex produced detectable levels of ipsdienol or myrcenol when fed for 24 hr on lodgepole pine,Pinus contorta var.latifolia Engelmann. The sex-specific conversion of myrcene to ipsdienol and myrcenol suggests that these compounds may have behavioral significance within the species. In addition, the S-(+)-ipsdienol produced by maleD. ponderosae probably functions as a repellent allomone againstIps pini (Say).