Violet tanbark beetle-Callidum violaceum (L.)
From Bugwoodwiki
From: Kolk A., Starzyk J. R., 1996: The Atlas of Forest Insect Pests (Atlas skodliwych owadów lesnych) - Multico Warszawa, 705 pages. Original publication in Polish. English translation provided by Dr. Lidia Sukovata and others under agreement with The Polish Forest Research Institute.
Occurrence: The northern, central and south-eastern Europe, reaching to the northern Mongolia, Korea and Japan, sporadically in the eastern North America
Host plants: Various conifers, rarely deciduous (oak, beech, alder).
Morphology: Adults are 8-18 mm long, flattened. Pronotum and elytrae are metallic blue, violet or greenish. The ventral part of the body is dark brownish. The body is covered with dark hair. Eggs are elongated, oval, 1.6 mm long. Larvae are up to 26 mm long, flattened. Pupae are 9-17 mm long, white.
Biology: Adults are active from May through July. They are often observed on breeding materials. Females lay eggs in bark crevices. Larvae feed under the bark. Galleries are up to 15 wide and 2-3 mm deep, curved, with sharp margins, filled with frass and shredded bark and wood. At the end, galleries are widened up to 2-3 cm, where larva enter into wood up to 10 cm deep and construct pupal chambers. Adult emerge through the same hole as the larva entered the wood, and chew the exit hole of 6 x 2-3 mm in the bark. This species has one generation per one or two years, in dependence climatic conditions
Damage: It is a technical pest of wood and wooden materials with bark. C. violaceum attacks weakened, dying and dead trees in 20-60 year old stands, choosing trees exposed to the sunshine.
Preventive measures and control: Debarking of wood. The exit holes found in wooden materials in different constructions should be closed by impregnated corks to avoid infection by fungi.
 Photo by Robert Dzwonkowski, , Bugwood.org |  Photo by Stanislaw Kinelski, , Bugwood.org |
 Photo by Stanislaw Kinelski, , Bugwood.org |  Photo by Stanislaw Kinelski, , Bugwood.org |
 Photo by Stanislaw Kinelski, , Bugwood.org |  Photo by Stanislaw Kinelski, , Bugwood.org |
 Photo by Stanislaw Kinelski, , Bugwood.org |  Photo by Stanislaw Kinelski, , Bugwood.org |
 Photo by Stanislaw Kinelski, , Bugwood.org |  Photo by Stanislaw Kinelski, , Bugwood.org |
