Pest description and crop damage A dark green caterpillar with two white stripes down each side feeds on needles. They do little damage except during outbreak years.
See "Pine" in:
Christmas Tree Plantation Pests
Chemical Control of Nursery Pests
For more information
Johnson, W.T. and H.H. Lyon (1991), Insects That Feed on Trees and Shrubs, 2nd ed., Cornell University Press (p. 24).