hosts include elm, ash, maple, hickory, walnut, aspen, willow, 
mountain-ash, and horse chestnut. Female scales vary from pure 
white to dirty gray, are somewhat pear-shaped, and are from 2 to 
3 mm. long. C. lintnert Comstock feeds on willow, birch, dogwood, 
and other trees and shrubs in southeastern Canada and the North- 
eastern States. C. corni Cooley often damages ornamental dog- 
woods in the Midwest. 
Chionaspis salicisnigrae (Walsh), the willow scurfy scale, occurs 
across the Northern States and in southern Canada. Willow ap- 
pears to be its favored host, but it also feeds on several other 
trees such as dogwood, poplar, yellow-poplar, and shadbush. 
Female scales are white, elongate-oval, convex, and about 8 to 4 
mm. long. Infestations are often heavy enough to cover completely 
the twigs and branches of its hosts. These may seriously injure 
young trees. 
The oystershell scale, Lepidosaphes ulmi (L.), occurs in south- 
ern Canada and throughout the United States. Its hosts include 
more than 100 species of forest, shade, fruit, and ornamental 
trees. Important species of forest and shade trees include white, 
European, and black ash, beech, silver maple, elm, willow, poplar, 
birch, and lilac. As its common name indicates, this scale re- 
sembles a miniature oystershell (fig. 31). The female is chestnut 
brown or darker and about 2.5 to 3 mm. long. 
Eggs overwinter under the protective covering of female scales. 
Hatching occurs in early June, or late May, or even earlier, de- 
pending on location. Newly-hatched nymphs wander over the bark 
for a short time, then settle down to feed. Eggs are laid during 
early summer in the South, and during late summer and early fall 
in the North. There are two generations per year in the South but 
only one in the North. 
The oystershell scale often occurs in such large numbers as to 
form a crust on the trunk or branches of its host. Damage to ash 
has been severe during past years. According to some reports, 
entire forest stands have been killed. Lilac and silver maple are 
also subject to serious injury. A related species, Lepidosaphes 
yanagicola Kuwana, first found and identified in Ohio in 1950, 
feeds on Kuonymus. 
The pine needle scale, Phenacaspis pinifoliae (Fitch), occurs in 
southern Canada and throughout the United States. Its hosts in- 
clude various species of spruces and the following species of 
eastern pines: white, red, Scotch, Austrian, Virginia, slash, lob- 
lolly, and mugho. Mature females are white, have a yellow pellicle 
attached to the anterior end, and are about 3 mm. long. They are 
usually widest toward the posterior end. The shape tends to vary, 
however, depending on the shape and width of the needles on 
which they live. Males are white and slender and not more than 
half as long as the females. 
Eggs spend the winter under the dead scale covering of the 
female. Hatching occurs about the time the new needles appear 
and the newly-hatched larvae crawl to green needles to feed. They 
become mature in early July and the new females produce new 
batches of eggs. Offspring of this generation reach maturity by 
fall and lay eggs which overwinter. There are two generations a 
year as far north as Ohio. 
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