The current, massive outbreak of mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae) in British Columbia has provided glimpses into beetle behaviors not generally observed during smaller outbreaks or suboutbreak periods.  An example of this is the ability of MPB to reproduce in mature spruce, Picea spp.  While MPB exhibits a large host range within pines, Pinus spp., attacks on Picea spp. are rare, and usually only occur when spruce are directly adjacent to mass-attacked pines.  In previous outbreaks, such attacks were not known to produce brood.  Recently, however, a number spruce were successfully colonized in the area around Prince George, British Columbia.  Two of the first MPB-colonized interior hybrid spruce detected in 2006 were extensively analyzed, along with two nearby, colonized lodgepole pines, Pinus contorta.  A number of parameters indicated that, in some circumstances, MPB reproduction can be as successful in spruce as in host pines.  Preliminary results of a subsequent replicated, paired-tree pheromone baiting experiment indicate differential attack timing of MPB on pine and spruce in a heavily infested stand.  Successful reproduction of MPB in spruce may simply be an artifact of extremely high population levels and/or due to the fact that the outbreak is occurring in populated areas with many observers who notice, and report, rare but normal phenomena.  In either case, the ability of some MPB to reproduce in spruce may relate to the insectÕs coevolutionary history with its various hosts and may provide insight into aspects of incipient speciation events.