Larvae feed in the inner bark of live, healthy dogwood trees. The damaged area of the trunk or branch swells and eventually the bark will fall off.
Leaves turning red prematurely in mid-summer on a lone branch are an early sign of dogwood borers.
Infested branches and limbs will die. Dogwood borers often will not kill the tree in the first year, but reinfestation in successive years will. Dogwood borer larvae are white with pale brown heads and they bore in the cambium of dogwood, gaining entrance under rough bark or through wounds. Late-summer adults are clear wing moths and somewhat resemble wasps. The body is blue with yellow stripes and yellow-banded legs.