FAMILY PHYLLOXERIDAE 
Members of this family resemble those of the family Aphididae 
but differ in that eggs are laid by both sexually perfect and im- 
perfect females. The majority of important eastern species feeds 
on the needles, twigs, limbs, and trunks or in galls on coniferous 
trees. 
The eastern spruce gall aphid, Adelges abietis (L.), an introduced 
species, occurs in southeastern Canada and the Northeastern and 
Lake States. Its preferred hosts appear to be Norway and white 
spruce, but it is also found occasionally on red and Colorado blue 
spruce. The winter is spent as small nymphs under coverings of 
waxy threads at the bases of buds on the undersides of twigs 
(765). The nymphs molt in the spring and become stem mothers 
which lay eggs on the needles. Hatching occurs in about 2 weeks 
and the young nymphs craw! to the bases of expanding buds. Here 
they feed, causing the formation of pineapple-shaped galls (597) 
in which they live and continue their development (fig. 19). Dur- 
ing late August to October the galls open and the full- -grown 
nymphs or “pupae” emerge. These transform to winged adults in 
a couple of days and, although they can fly, many-remain on the 
tree. The females insert their mouth parts through the bark, 
deposit upwards to 60 eggs each and then die. These eggs hatch 
within 16 days and the young nymphs immediately crawl to over- 
wintering sites. There is one generation per year. 
COURTESY CONN. AGR. EXPT. STA. 
FIGURE 19.—Galls of the east- 
ern spruce gall aphid, Adel- 
ges abietis, on spruce. 
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