The pine leaf adelgid, P. pinifoliae (Fitch), occurs in both the Eastern and 
Western United States. Its range in the East coincides with that of its primary hosts. 
red and black spruces. wherever they grow close to its alternate host, white pine. 
The offspring produced by aduits migrating from spruce provide the easiest means 
of diagnosing an outbreak on pine. The small, scalelike “larvae” are fringed with 
white hair and often become numerous enough to cover a shoot completely. 
The life cycle takes 2 years to complete. During part of this time, including the 
first winter, infestations are found entirely on spruce; during the remaining time, 
including the second winter, they are found on pine (752). 
Infestations on spruce result in the production of terminal compact galls that have 
the appearance of true cones consisting of many chambers, each containing a single 
adelgid. These galls are of minor importance except on ornamentals, where they 
may be undesirable. Heavily infested white pines, especially young pines in 
plantations, may be severely injured. The early symptoms are drooping branches 
that turn red by summer, and die. In heavy infestations, growth is reduced and 
occasionally trees up to 12 cm in diameter are killed. Some outbreaks spread over 
large areas before subsiding. 
Pineus floccus (Patch), the red spruce adelgid, feeds on red and black spruces 
and eastern white pine, spending | year of its 2-year life cycle on each. It produces 
loose, terminal galls on spruce. On pine, its effects are similar to those caused by 
the pine leaf adelgid. Heavy infestations on spruce may kill the tips of branches or 
they may cause an overproduction of laterals, which leads to bushy, deformed trees. 
Damage to pine is usually not serious. 
Pineus similis (Gillette), the spruce gall adelgid. produces terminal ragged galls 
on various spruces but appears to prefer white spruce in the East. No alternate hosts 
have been found for this species. The galls are shorter and thicker than those 
produced by the Cooley spruce gall adelgid and the chambers inside are intercom- 
municating. Small white spruce growing in the open in Canada has been severely 
infested. P. coloradensis (Gillette) has been observed feeding on the needles of red 
and pitch pines in Connecticut, although its host range is much wider (774). 
Laboratory studies indicate that red pine seedlings readily succumb to heavy 
infestations of this species. 
Family Phylloxeridae 
Phylloxeras 
Members of this family res able those of the family Adelgidae except that 
winged forms have fewer antermal segments and all species feed exclusively on 
dicotyledonous plants. 
The genus Phylloxera contains several species that produce galls on hickories 
and pecan. These aphids do not produce waxy threads as do many other members of 
the family. but some of them may be covered with a waxy powder. Their galls vary 
from small disklike or buttonlike swellings, with central openings guarded by 
plantlike hairs or processes, to large, hollow, globelike structures up to 18 mm in 
diameter. 
Phylloxera caryaecaulis (Fitch), the hickory gall phylloxera, is a common 
species that produces almost spherical galls, 16 to 18 mm in diameter, on the twigs 
and leaf stems of hickory. The galls are green when first formed: later, after the 
phylloxeras vacate them, they turn brown or black. The pecan phylloxera, P. 
devastatrix Pergande. and the pecan leaf phylloxera, P. notabilis Pergande. pro- 
duce galls on pecan and other hickories. P. rileyi Riley is found on white and post 
oaks. and P. nyssae Pergande infests blackgum. 
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