Require 1-3 years to complete development. Adults lay eggs on bark. Larval galleries score the sapwood. Later larval instars bore into the sapwood where they complete their development. Grubholes flattened, upper and lower surfaces parallel, packed with frass.
Exit holes elliptical.
Larvae have been known to take 30 years to complete their development in structural timbers. The emergence holes sometimes penetrate roofing materials which results in leakages.