There are two species of tent caterpillars that can be found in Washington. The western tent caterpillar is most commonly found in western Washington. It attacks a wide range of hosts including apple, peach, plum, cherry, pear, wild rose, poplar and willow. The forest tent caterpillar is the other species found in Washington. It is approximately 2″ long and has a bluish body with black and white markings. Its silk mats are found on branches and trunks. It prefers maple but will also feed on the foliage of most types of fruit trees.