Great spruce bark beetle (Dendroctonus micans)

Kolk A. and Starzyk J. R. 1996.The Atlas of Forest Insect Pests. The Polish Forest Research Institute. Multico Warszawa. 705 pp.

Occurrence

The central and northern Europe, Siberia and Japan.

Host plants

The Norway spruce, rarely Scots pine and larch.

Morphology

It is the biggest European bark beetle of 6-9 mm in length. The body is robust, cylindrical, black or dark brown, covered with tiny yellowish hair. Elytrae are with rows of punctures. The declivity is covered with reddish hair.

Biology

Adults fly from May through August. After mating, females chew egg galleries under the bark. Egg galleries are up to 10 cm in length, irregular and made in the basal part of the stem. They infest living trees, thus pink-whitish, funnel-shaped pitch tubes are formed around entrance holes. The female lays up to 100 eggs in interconnecting chambers, on one side of the chamber. Young larvae feed in groups on inner bark and phloem packing a mixture of frass and shredded bark behind them. Pupae are found in pupal cells among the larval frass. Emerged adults have maturation feeding near pupal chambers. The overwintering occurs in the imaginal or larval stage. This species usually has one generation per year.

Damage

In Poland this beetle is quite rare. Locally it can make damages in 20-40 year old stands, first of all infesting wounded trees or trees damaged by lightning.

Preventive measures and control

Avoiding wounds on living trees during harvesting operations. Removal of infested trees, especially those attacked by root fungi or other pests, is recommended.