identified in interior Alaska: white spruce/feathermoss; white spruce/dwarf birch/feathermoss; white spruce/dwarf birch/sphagnum; white spruce/avens/moss; and white spruce/alder/bluejoint. Of the Eastern Forest Cover Types recognized by the Society of American Foresters, only one, White Spruce, names that species in its title. The eastern White Spruce Cover Type, as defined, encompasses white spruce both in pure stands, and in mixed stands "in which white spruce is the major [undefined] component." In most of its range, white spruce occurs more typically in association with trees of other species than in pure stands. White spruce is an associated species in the following Eastern Forest cover types, by the Society of American Foresters; in the Boreal Forest Region: (1) jack pine, (5) balsam fir, (12) black spruce, (16) aspen, (18) paper birch, and (38) tamarack; in the Northern Forest Region: (15) red pine, (21) eastern white pine, (24) hemlock-yellow birch, (25) sugar maple-beech-yellow birch, (27) sugar maple, (30) red spruce-yellow birch, (32) red spruce, (33) red spruce-balsam fir, (37) northern white-cedar, and (39) black ash-American elm-red maple. Predators Outbreaks of spruce beetles have destroyed over of forests in Alaska. Although sometimes described, e.g., by Switzer (1960), as relatively resistant to attack by insects and disease, white spruce is far from immune to depredation. Important insect pests of white spruce include the spruce budworm (Choristoneura fumiferana), the yellow-headed spruce sawfly (Pikonema alaskensis), the European spruce sawfly (Gilpinia hercyniae), the spruce bud moth (Zeiraphera canadensis), and spruce beetle (Dendroctonus rufipennis). As well, other budworms, sawflies, and bark beetles, gall formers, bud midges, leaf miners, aphids, leaf eaters, leaf rollers, loopers, mites, scales, weevils, borers, pitch moths, and spittlebugs cause varying degrees of damage to white spruce. A number of sawflies feed on spruce trees. Among them European spruce sawfly, yellow-headed spruce sawfly, green-headed spruce sawfly and the spruce webspinning sawfly. More than a dozen kinds of looper feed on the spruces, fir, and hemlock in eastern Canada. The full-grown larvae of the larvae vary in length from 15 mm to 35 mm. Some feed briefly in the fall and complete their feeding in the spring; others feed mainly in the summer; still others feed mainly in the late summer and fall. The fall and spring feeding group includes the dash-lined looper (Protoboarmia porcelaria indicataria), the diamond-backed looper (Hypagyrtis piniata), the fringed looper (Campaea perlata), and the false loopers (Syngrapha species). The summer feeding group includes the false