Walks, benches, or cars parked beneath infested trees are often badly soiled. The 
related species, the Norway maple aphid, P. /yropictus (Kessler), often completly 
defoliates Norway and sugar maple trees. Honeydew dripping from infested leaves 
is a nuisance. P. americanus (Baker); Drepanaphis carolinensis Smith; D. 
nigricans Smith; D. sabrinae Miller; the painted maple aphid, D. acerifoliae 
(Thomas); and Drepanosiphum platanoidis (Schrank), the sycamore maple aphid, 
are also found on maples. 
Numerous species of Myzocallis such as M. bellus (Walsh), the greater striped 
red oak aphid; M. punctatus (Monell); M. discolor (Monell); and M. melanocera 
Boudreaux & Tissot feed on various oaks. Other common members of related 
genera and their hosts include: Prerocallis alnifoliae (Fitch)—alder; Eucallipterus 
tiliae (L.), the basswood aphid—native and introduced lindens; the crapemyrtle 
aphid, 7inocallis kahawaluokalani (Kirkaldy)—crapemyrtle; the black pecan ap- 
hid, Melanocallis fumipennellus (Fitch)—hickory and pecan; and the elm leaf 
aphid, Jinocallis ulmifolii (Monell)—elm. 
Many other species of free-living aphids also occur commonly on various 
deciduous trees. These include the black-margined aphid, Monellia costalis 
(Fitch), M. caryella (Fitch), M. microsetosa Richards, and M. nigropunctata 
Granovsky on hickories; Chaitophorus stevensis Sanborn, C. populicola Thomas, 
and Tuberolachnus salignus (Gmelin) on poplars; Pterocomma populifoliae (Fitch) 
and P. smithiae (Monell), the black willow aphid, on poplars and willows; P. 
salicis (L.), on willow; the tuliptree aphid, ///inoia liriodendri (Monell), on 
yellow-poplar and magnolia; the cowpea aphid, Aphis craccivora Koch, on black 
locust seedlings; Phyllaphis fagi (L.), on nearly all species of beech; Calaphis 
betulaecolens (Fitch), the common birch aphid, on birch (often in large numbers); 
C. betulella Walsh, on birch and beech; Euceraphis punctipennis (Zetterstedt), the 
European birch aphid, on various birches, especially yellow birch; FE. lineata 
Baker, on gray birch; and E. mucida (Fitch), on river birch. 
Three species of woolly aphids are commonly found on elms in the Eastern 
United States. The woolly apple aphid, Eriosoma lanigerum (Hausmann), feeds on 
new terminal leaves, causing them to curl or appear in the form of rosettes. It 
attacks apple, pear, hawthorn, and mountain-ash. Damage to elms is not especially 
severe. The presence of large numbers of distorted leaves on shade trees is 
unsightly. The woolly elm aphid, EF. americanum (Riley), has elm as a primary 
host and serviceberry as an alternate host. It feeds at the edges of young elm leaves 
in the spring, causing them to swell, curl, and roll inward from the edge. Two 
generations are produced on elm. Members of the second generation then fly to 
serviceberry and attack its roots. The summer is spent here. During the fall, a 
winged generation develops and flies back to the elm, where it lays a cluster of 
overwintering eggs. E. rileyi Thomas, the woolly elm bark aphid, attacks Ameri- 
can and slippery elms. It occurs in dense woolly clusters on the limbs and trunks, 
causing knotty growths to form at the sites of injury. Heavily infested trees may be 
seriously injured. Hawthorn is infested by the closely related species, E. crataegi 
(Oestlund). It occurs in dense colonies in twigs and branches and is occasionally 
injurious to ornamentals. 
‘Several other woolly aphids are also found on various species of hardwoods. The 
beech blight aphid, Fagiphagus imbricator (Fitch), feeds primarily on the bark of 
twigs and small branches, but also can be found on the trunk and undersides of 
leaves of beech trees from New England to Georgia and Illinois. Its body is covered 
with a white, cottony substance that strings out in fairly long threads and forms a 
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