Hardwood stump borer (July 11, 2013)

Guest post by Sydney Glass, Integrated Pest Management Intern.

Two people from Texas submitted hardwood stump borer beetles for identification this week.


The hardwood stump borer is around two inches long, having a black to almost dark violet or dark purple tint. Sometimes the beetles have patterns to help camouflage them into their surroundings. The hardwood stump borer male has long antennae,and the females have shorter antennae. Males have a slender body whereas the females are rounder. Both sexes have very visible mandibles (mouth pinchers).


Hardwood stump borer beetles are nocturnal and found in open places like sandbars, rocky areas, and anywhere close to trees and woodlands.  The beetles are fast, fly quickly, and are extremely active. The hardwood stump borer is a predator and is an opportunistic feeder on any insect it can catch. The adult mates in the late summer/fall and lays eggs on the underside of tree bark. When the egg hatches, the larva “bores” into the wood and feeds, later to pupate and emerge as an adult.


The hardwood stump borer is not an aggressive beetle and is not considered dangerous, the hefty mandibles it has will draw blood if handled carelessly and aggressively.


Hardwood stump borer. Photo Credit: Ron Becker