Oak splendor beetle can be found in Europe (north to southern England), Middle East, Siberia and northern Africa. It has not been reported in North America.
Eggs are laid in bark crevasses in clusters of 5-6 eggs. The larvae are creamy white, legless grubs around 25-40 mm (1-1 3/4 inches) in length when mature. The first thoracic segment is wider than the other body segments. Two horn/pincer-like projections (urogomphi) are found on the last abdominal segment. The pupae are white and can be found in chambers within the bark. Adults are attractive, metallic green, slender; 8-13 mm (1/3-1/2 inch) in length; present May to July. The end third of the wing covers have two distinct white marks on the inside edge.
This beetle may have one generation a year in warm climates, but a two-year cycle is more common. Like other metallic wood-boring beetles, including emerald ash borer, they are strong fliers which are able to fly several kilometres in search of a suitable host. Adults engage in some maturation feeding in addition to laying eggs. The south side of large oaks (diameter at breast height of 30-40 cm (11-15 inches)) is preferred for oviposition. Larvae feed in the cambium creating frass-filled 'zig-zag' galleries. Pupation occurs in the bark. The insect overwinters in both the larval and pupal stages. In mid-spring, adults emerge leaving D-shaped exit holes.
Plant Response and Damage
Dieback, development of epicormic branches, thin crown, and tree mortality are typical. This is due to the destruction of the cambium. Callus growth and bark cracking may be observed as the tree attempts to compartmentalize the injury.