They are North America's largest weevil. They start as eggs laid in the leaves or damaged areas of a tree. About three days later the eggs hatch and the grubs begin to feed on the tissues of the tree. The larvae grow by moulting and with each new moult their appetites increase. In their final stage the larvae move from deep within the tree to the outer area and spin cocoons around themselves.
Weevils emerge from the cocoons several weeks later to mate.
This entire cycle takes about 12 weeks. Mature insects are most noticeable in late spring and early summer.