Dendroctonus micans (Kug.) and cambioxylophagous fauna of blue spruce (Picea pungens Engelm.) in Central Europe

Cambioxylophagous fauna was studied in monocultures of introduced blue spruce (Picea pungens) in the air-polluted area of the Ore Mountains (Krušné hory), Czech Republic, Central Europe.The great spruce bark beetle (Dendroctonus micans) was the most important mortality factor of blue spruce trees in the study area. It created smaller but long-persistent gaps in forest stands, causing gradual death to healthy trees with living phloem.The tree stems attacked by the beetle were subsequently colonized by other scolytid species, of which Ips amitinus, Pityogenes chalcographus and Cryphalus abietis were the most important. Diameter at breast height (dbh) of analysed blue spruce trees was not a limiting factor for the occurrence of Dendroctonus micans with respect to the markedly thickened basal part of even low-diameter trees. Two scolytid species, Cryphalus abietis and Pityogenes chalcographus, occurred predominantly in branches.