bark wood beetle pest ips typographus infestation, spruce and bast tree infested attacked by european spruce, making

attacked bark bast beech beetle burrow calamity caterpillar caused chop closeup cut cycle czech dead detail down ecological environment europe european forests hole infestation infested insects interactions ips larva larvae logging making opening part pest phloem pine planting pupa salvage scolytinae small spruce stands stump tree trees typographus way wood