Adults of this species are born between mid-June and mid-August, and males can grow to double their body length.
Both sexes have a white patch at the base of their wings, and they may have white dots all over their wings. Adults graze mostly on pine and spruce species for up to seven days after emerging.
Females carve little egg niches into dead or decaying trees or logs after mating, into which they deposit one egg each.
Both sexes mate with various partners repeatedly, and females lay between 15 and 20 eggs on average per lifespan. When the larvae hatch, they burrow into the phloem and cambium to feed until they emerge.
Host plants: Balsam fir, spruces and white pine
Territory:
The white-spotted sawyer, often known as the spruce sawyer or spruce bug, is a widespread wood-boring beetle found in North America. It is a North American natural species.
Damage caused by Whitespotted Sawyer:
The adult beetles feed on the bark on the underside of twigs, causing the tips to die and become red. Look for a wound near the base of the dead shoot. Otherwise, the beetle is typically a secondary pest, attacking the trunks of weaker, dying, or dead trees. Small mounds of sawdust may be found around the base of trees where larvae have tunnelled.
Life history and Habits:
The life cycle lasts one or two years. Adults emerge from circular exit holes in the wood throughout the summer. They eat on twig bark, causing the tips to flag. Eggs are placed in the fissures of the bark of frail, recently deceased, or newly cut trees. When the eggs hatch, the tiny larvae burrow a tunnel into the cambium through the phloem. Larvae mine beneath the bark as they grow. Later, instars burrow into the heartwood. The larva twists its tunnel toward the surface before pupating, where it pupates behind a chip plug.
