Overview
Oak splendor beetle is native to Asia. It has not been found in North
America. Like other metallic wood-boring beetles, including emerald
ash borer, they are strong fliers which are able to fly several miles in
search of a suitable host. They are readily moved in wood products
such as firewood or other materials with attached bark. Oak is the
primary host, but chestnut and beech are also susceptible. This beetle
may have one generation a year in warm climates, but a two-year cycle
is more common. Adult females feed on oak foliage before depositing
clusters of 5-6 eggs in bark crevasses. The south side of large oaks
(diameter at breast height of 11-15 inches) is preferred. Larvae feed in
the cambium creating frass-filled, ‘zig-zag’ galleries. Mature larvae are
creamy white, legless grubs around 1-1 3/4 inches in length. The first
thoracic segment is wider than the other body segments. Two hornlike
projections (urogomphi) are found on the last abdominal segment.
Pupation occurs in the bark. The insect overwinters in both the larval
and pupal stages. In May to June, adults emerge leaving D-shaped
exit holes. Adults are attractive, metallic green, slender insects about
1/3 to 1/2 of an inch in length. The posterior third of the wing
covers have two distinct white marks on their interior edge. Damage
typically results in dieback, development of epicormic branches, thin
crown, and tree mortality.