Bark beetle dron aerial video shot pest Ips typographus dead, spruce, planting of fast-growing white birch trees Betula pendula silver birch, warty birch, European white birch and bast tree infested and attacked by European spruce view flying fly flight show, cutting deforestation making their way in wood larva and larvae, clear cut calamity wood small-reed caused bushgrass, by bark beetle due to global, opening part of hole, non-original planting of spruce stands, Czech Republic, Europe