132 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
or apterous, and wax production is ee developed. A discussion of 
this tribe was given by Maxson (292, pp. 319-328). ; 
These aphids are seldom of any importance as pests of forest and 
shade trees. Nevertheless, some species are sometimes so numerous as 
to occasion alarm. 
The beech blight aphid (Prociphilus imbricator (Fitch) ), a large, 
downy-woolly species, infests the under sides of branches and some- 
times the trunks of beech. Moreover, there are records of its having 
infested sycamore (Fitch, 75S, p. 68; Hottes and Frison, 238, pp. 372- 
FIGURE 26.—Females of Prociphilus tessellatus: A, On leaves of soft-maple; B, on 
alder stem; C, on bark of maple. 
373). It occurs from New England west to Illinois and south to 
Georgia and Tennessee. The woolly alder aphid (P. ¢essellatus 
(Fitch) ) is sometimes locally important on alder and maple. It is 
distributed throughout the Eastern States (fig. 26). Prociphilus 
bumeliae (Schrank) i is reported as the cause of root mortality of young 
white pine trees in Michigan. 
The genus Neoprociphilus is another group of aphids in this tribe 
that infests trees. WV. aceris (Mon.), a flocculent species, is reported on 
sugar maple from New England west to Illinois and south to North 
Carolina (Hottes and Frison, 238, pp. 361-363). Owing to lack of in- 
formation on the complete life cycle of this species, it is s considered to 
