Widespread and severe tree mortality can occur during epidemics. The broad and prominent head has a distinct notch or frontal groove on male beetles. The rear end or abdomen of adults is rounded. Eggs are ca. 1.5 X 1.0 mm, oval in shape, shiny, opaque and pearly white.
Pupae have the same general color of larvae and the same general form and size of adults.
After locating a suitable host tree, a female beetle bores through the bark to initiate gallery construction in the inner phloem. This pheromone, in conjunction with host odors stemming from resin exudation at attack points, attracts more SPB to the tree. Mass-attacking enables the beetles to overcome the natural defense mechanism of the tree, its resin production system. Resin under pressure within the tree can successfully force out or pitch out beetles if there are only a few beetles and the tree is relatively healthy. Mass-attacking SPB deplete the resin production capabilities of the tree causing resin flow to cease, after which point the tree is easily overcome.