Attracttion of bark beetles (Coleoptera: Scolytidae) to Norway spruce in timberline forest in Tatra Mountains, West Carpathians

Attraction of bark beetles (Coleoptera: Scolytidae) to Norway spruce was studied in the timberline forest in Tatra Mountains, West Carpathians, Central Europe, by trapping bark beetles in flight interception traps fixed to the lower parts of the 18 trunks of spruce trees, and by recording colonizations of bark beetles on those trees in 2004. The trees were devoid of needles in the upper crown (1/4 up to 1/3 of the tree top dead) and were growing in three distant sample plots. Each plot was representing three different situations (biotopes) in the timberline spruce forest - forest, forest line and tree line, in altitudes between 1,280-1,560 m. A total of 18 traps yielded a total of 5,015 individuals and 19 bark beetle species associated with spruce, the five of which, Phtorophloeus spinulosus, Xyloterus lineatus, Pityophthorus pityographus, Pityogenes chalcographus, Ips typographus, were also documented to be developing in the the studied trees. Traps in the forest line yielded more individuals of bark beetles (all species considered together) than those in the forest and the tree line, although this was not significant (P>0.05, K-W Anova). The bark beetle assemblages showed very low dissimilarity in their structure between the forest and forest line, however, the assemblages in these two situations, aparently, differed from the assemblage in the tree line. Over the period 2004 - 2008 three (16.7%) of the 18 studied trees died. All documented cases of the tree mortality were associated with colonization by I. typographus.