Cinara strobi
See:
Pest description and crop damage Colonies form in groups on needles. An extensive infestation yellows the tree and promotes sooty mold.
See "Pine" in:
Christmas Tree Plantation Pests
Management-biological control
See:
Biological Control of Nursery Pests
Management-chemical control
See:
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. 84).