Black locust borers are beetles that specialize in attacking one genus of tree, the black locust. Females lay eggs on the bark and larvae tunnel into the trees. They hibernate over the winter. In spring, they become active again, and by late summer, a larva has dug up to 10 cm (4 in) of tunnel, .6 cm (¼ in) in diameter. This tunnelling weakens the trees to the point that some break from the wind.