Lachnus salignis and other species
Pest description and crop damage Large gray to gray-black aphids often are in large numbers on twigs, branches, and trunk. Their legs generally are light brown. A prominent black tubercle is in the center of the back with slightly smaller tubercles on either side. Aphids may be a nuisance around homes when they collect on the sides of the house and crawl through window openings.
For more information
Johnson, W.T. and H.H. Lyon (1991), Insects That Feed on Trees and Shrubs, 2nd ed., Cornell University Press (p. 310).