Tent caterpillars on their way home after a hearty vegetarian meal.
A recurring epidemic on the Point, tent caterpillars are once again defoliating local trees this year. The infestation at Lily Point is so severe in areas that some park users have taken to wearing hoods to prevent the orange and black caterpillars, and their rain of feces, from falling onto hair and clothes.
The caterpillars prefer alder and fruit trees. To protect your fruit trees from the pest, Washington State University Extension recommends checking for and removing the spongy egg masses in early spring before they hatch. Once the eggs have hatched and the tent has been spun, it is best to cut the nests out of fruit trees and dispose of them.
Burning the nests in the tree is not recommended because of the fire hazard. If the caterpillars are already out and feeding, biological control can be achieved by spraying or dusting with Bacillus thuringiensis (Bt).
For more information, visit gardening.wsu.edu/library/inse003/inse003.htm.