Several species of butterflies damage the cork oak, the most important being the gypsy moth ("Lymantria dispar"). The species lays its eggs in the bark of the branches and trunks, and the caterpillars that hatch in spring are distributed in the crown and eat them bare. The bacterial species "Bacillus thuringiensis" is used as a biological plant protection agent against the gypsy moth. Another pest is the green oak tortrix ("Tortrix viridana"), whose caterpillars eat flowers and young leaves and roll them up with thread to form typical coils. The lackey moth ("Malacosoma neustria") also causes damage to the leaves, sticking its eggs to the bark of thin twigs in multiple rows, and also the brown-tail moth ("Euproctis chrysorrhoea"), whose caterpillars skeletonize the leaves and further damage the tree after overwintering in spring . A special cork pest is the jewel beetle Coraebus undatus, which lays its eggs in the cork tissue. A special cork pest is the jewel beetle "Coraebus undatus", which lays its eggs in the cork tissue. Another harmful species of beetle is the great capricorn beetle ("Cerambyx cerdo"), whose larvae eat long corridors in the oak wood.