Ten species of flatheaded borers of the family Buprestidae feed on spruce and fir, but hemlock is their preferred food source (Rose and Lindquist 1985). As with roundheaded borers, most feeding occurs in dying or dead trees, or close to injuries on living trees. Damage becomes abundant only where a continuing supply of breeding material is available. The life history of these borers is similar to that of the roundheaded borers, but some exceedingly long life cycles have been reported under adverse conditions. Full-grown larvae, up to 25 mm long, are characteristically flattened, the anterior part of the body being much broader than the rest. The bronzed adults are usually seen only where suitable material occurs in sunny locations.