Subject: large 2” beatle
Location: Fairmont, West Virgina
June 25, 2013 8:27 pm
I saw some of these last year around the same time ( June, July). I see them around an old rotting stump with their tail ends in the air, or just running along the ground. I live in northern West Virginia and thought they may be hardwood stump boring beetles, but I didn’t think we had them this far north. They are probably the biggest beetles I have seen in person. Is that what these are, and are they supposed to be this far north?
This is a female Broad-Necked Root Borer, Prionus laticollis. The reason you have seen them around an old stump is that the larvae are borers. According to BugGuide: “Eggs are inserted into ground (or under litter) in groups. Larvae tunnel downward to feed on living roots of a variety of trees and shrubs. At first they may feed on bark, but then proceed to hollow out small roots. Pupation occurs in spring, about 10 cm under the ground. Life cycle probably three years.” BugGuide reports sightings as far north as Maine and they are also found in Canada, so your West Virginia sighting is not unusual.