filamentous ovisac in late spring and summer and require a period of at least 20 
. days to hatch. First-instar crawlers appear in late summer or early fall and settle in 
cracks or lenticels on the trunk or large branches of the host. Soon after settling, the 
crawler produces a woolly secretion that encloses the body. The crawler is normally 
the overwintering stage, although eggs are occasionally found during this period. 
Through the winter the crawlers change in form from oval to pyriform. In the spring 
the crawlers molt to the second instar, which apparently is short in duration. This 
instar, like the adult female, is enclosed within a woolly, waxlike secretion, 1s 
legless, and is yellow. Adult females are present in the spring and most of the 
summer. 
The first sign of an infestation is the appearance of isolated, minute, white 
woolly dots on the bark, usually near the base of the tree. As the infestation 
increases, the dots appear in the form of thin vertical lines and then as solid patches. 
On heavily infested trees, the trunks (fig. 35) and lower sides of branches may be 
completely whitened. Light infestations are not particularly injurious, but when 
they increase to about 15 scales per square centimeter, the bark is killed and turns 
brown. Depressions or pits in bark tissues around these wounds are frequently 
numerous on young trees. The death and shrinkage of groups of cells within feeding 
areas Cause ruptures in the bark. Death of the tree does not usually occur until 2 to 5 
years after infestation. A fungus, Nectria coccinea Pers. ex Fr. var. faginata 
Lohman, Watson and Ayres, gains entry through these ruptures. It penetrates the 
cambium and sapwood, killing tissues and interfering with the conduction and 
storage processes of the tree. Red fruiting bodies produced by the fungus become so 
abundant in some infestations that large areas on the trunk turn red. This infection 
leads to death of irregular-shaped areas of bark. Individual fungal lesions also 
coalesce and girdle the trunk, leading to crown deterioration and finally to death of 
the tree. The fungus is entirely dependent upon the scale for its incidence and 
spread. 
Figure 35.—Infestations of the beech scale, 
Cryptococcus fagisuga, on the trunk of beech. 
Enormous quantities of beech have been killed; the only way to prevent such 
losses is through cutting and removal of infested trees (/080). This is true despite 
the fact that some degree of natural control is provided by several predators, 
including Chilocorus stigma (Say). Winter temperatures of — 38° C are highly 
effective in the control of infestations exposed above the snow line (45). 
Another species of Cryptococcus may be found in eastern forests. C. williamsi 
Kosztarab & Hale is found on sugar or, rarely, red maple in Maine, New 
102 
