California, and east, into the Rocky Mountains. Hosts: Prevalent in oak, madrone, poplar and apple; also attacks cherry, walnut, chestnut, willow, serviceberry, eucalyptus, pear, almond, peach, plum, quince, alder, hop, some conifers, brambles and certain shrubs. Biology: Adults fly June to September; females may lay up to 600 eggs; lifecycle takes 3-5 years. Importance: Larvae bore into bark at plant bases, and penetrate roots; leaves yellow, then defoliate; bark on larger branches dries and cracks. Plants often die the following season. Serious pest of apples in New Mexico.