The Evaluation of the Bark Beetles Populations on Spruce Logging Debris

Abstract

Today, when somebody is talking about bark beetles management, there are two different approaches. The first one includes bark beetles in the category of pests and the second one includes bark beetles in the category of insects with important ecologic role in forest. From our point of view, up to particular limits, both approaches remain valid. Thus, in our research raise the problem of bark beetles population level into logging debris, which remains in the forest after clear-cutting. In our research, we started with the hypothesis that in logging debris a high number of bark beetles can multiply sufficient to install after that in neighbors standing trees. From our samples resulted seven bark beetles species as follows: Ips typographus, Ips amitinus, Ips acuminatus, Pityogenes chalcographus, Dryocoetes autographus, Hylurgops palliatus, Hylurgops glabratus. The most numerous were I. typographus (43%), P. chalcographus (40%), and H. palliatus (9%). The preferences for the thickness of logging debris had just P. chalcographus and H. palliatus. All the rest of the species preferred in equal mode thick or thin logging debris. Regarding the felling date of trees, we can affirm that cutting of trees early in spring may limit the beetles spreading. About logging debris management, our results show the necessity of their removal from forest and capitalization, because they are hosts for many bark beetles.