Pest description and crop damage Larvae of a clearwing moth feed in tree limbs and trunks. Trees under attack are almost always previously stressed. A mass of pinkish pitch at the feeding site is evidence of infestation.
See "Pine" in:
Christmas Tree Plantation Pests
Sampling and thresholds Pheromone traps are available.
Keep trees vigorous.
Chemical Control of Nursery Pests
Apply materials to the trunk and lower limbs. Avoid contacting foliage. Apply generally in late spring or when adults are active.
For more information
Johnson, W.T. and H.H. Lyon (1991), Insects That Feed on Trees and Shrubs, 2nd ed., Cornell University Press (p. 72).
PNW Nursery IPM: Sequoia pitch moth (http://oregonstate.edu/dept/nurspest/sequoiapitchmoth.htm)