Pine Sawyer Beetle

On the morning of June 3, 2017, I discovered a dead Pine Sawyer Beetle floating in my swimming pool. Having read several descriptions of its habitat, I think it is strange to have this beetle in the Coachella Valley of Southern California. I have a picture of it, but being brand new to this site, I do not see a way to display it here.

Description: This is the largest beetle in western North America. They can reach 65 mm in length. They are slender and flattened. Elytra are reddish brown with a few distinct ridges. The pronotum and head are much darker. The margins of the thorax have a few large spines and usually several smaller ones. Antennae are over half of the body length and tend to lay back along the length of the body. The eyes partially surround the base of the antennae. The mandibles are fairly large.

Habits: Adults lay eggs in crevices in the bark of the snags, logs, and stumps of Douglas fir, pines, firs, and redwoods. Larvae excavate large tunnels within the sapwood and heartwood. Although detrimental to the logging industry, they are a naturally occurring element of western forest ecology. La... read morervae significantly help to speed the deterioration of dead trees. Trees killed by fire or infestation or other insects are often mined at the base by the Pine Sawyer, making them fall quickly. This helps to deter forest fires. The feeding habits and form of the larval mandibles gave a logger the idea for the modern chain saw. Their life cycle lasts several years. Adults emerge in July and August.

Range and Habitat: Ergates spiculatus occurs throughout mountain forests of the western states and north to British Columbia. Adults can be found in the canopy and amongst snags, stumps, and downed logs. Larvae are found within wood.

Abundance: Uncommon.

Ecological Role: Pine Sawyers significantly increase the rapidity of snag, stump, and log decomposition by mining large burrows into the heartwood. Unfortunately, they can also greatly diminish the value of salvage timber where they are abundant.