Monochamus obtusus Casey 1891

Uncommon.

Adults are active from June till August (Linsley and Chemsak, 1984).

Occur in British Columbia, Idaho, Washington and California (Linsley and Chemsak, 1984).

14-24 mm, integument reddish brown, abdomen black, hairs gray or brown. Antennae extending 5 segments past elytra in males and 3 segments past in females. Small round lateral projections on pronotum. Scutellum v-shaped with white hairs on sides. The subspecies Monochamus o. obtusus is distinguished by darker integument and hairs with reduced gray hairs. Monochamus o. fulvomaculatus has light brown integument with numerous gray hairs (Linsley and Chemsak, 1984).

Pine woodlands.

As in other Monochamus species adults will feed for a short period, mate, and the female will lay eggs in irregular shaped holes in coniferous trees. Larvae will emerge and begin feeding on the wood under the bark causing oval shaped tunnels. No information on the duration of the lifecycle is mentioned, but since they only occur in warmer areas one could assume it is the 1 year cycle.

Larvae and adults have been known to feed on dead and dying pine, true firs, and Douglas fir (Linsley and Chemsak, 1997).

Monochamus obtusus is a species of beetle in the family Cerambycidae. It was described by Casey in 1891.