birch. Damage to beech consists of roughened or swollen spots of 
bark up to 2 inches in diameter. These spots dry out as they age, 
and additional cracks form around them. Damaged spots may be 
found over the entire trunk, but they usually occur in narrow 
longitudinal strips, starting at old branch stubs. 
FAMILY KERMOCOCCIDAE 
Kermes pubescens Bogue is often a serious pest of oaks in the 
eastern half of the United States, especially in the Midwest (476). 
Adult females are light brown, almost spherical, and about 2.5 
mm. in diameter. Eggs are laid on new growth from late June to 
late July. Newly-hatched larvae migrate to the trunk and larger 
limbs where they hide, in cracks or beneath loose bark. They 
remain here without much growth until the following spring, at 
which time they craw! to the new growth and resume feeding. 
Heavy infestations on petioles and midveins may cause the distor- 
tion or death of leaves and twigs. On heavily infested trees, the 
flagging of terminals may be so severe by late July that the 
beauty of shade and ornamental trees is greatly reduced. K. galli- 
formis Riley, K. kingw Ckll., K. pettiti Ehrh., and K. trinotatus 
Bogue are also fairly common on oaks in the Eastern States but 
they are seldom injurious (fig. 25). 
FAMILY ERIOCOCCIDAE 
The beech scale, Cryptococcus fagi (Baer.), an introduced 
species, was first recorded in North America in Nova Scotia 
around 1890 and in the United States at Boston, Massachusetts, 
in 1929. It now occurs throughout the beech-growing areas of 
New England, eastern New York, Pennsylvania and New Jersey, 
and the Maritime Provinces of Canada. Its hosts are American 
and European beech and their varieties. Female scales (no males 
have been found) are circular-shaped, 0.5 to 1 mm. long, and. 
covered with a woollike wax. 
Young larvae overwinter and their development is completed in 
the spring. Egg laying begins in early June or later, depending on 
location, and continues into July. Hatching begins by August 1 in 
some areas. The young larvae crawl over the bark until a suitable 
feeding site is found. There they insert their stylets, become 
quiescent, excrete a white, wooly wax and eventually spend the 
winter. There is one generation per year. 
2 
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FIGURE 25.—Female scales of 
Kermes sp. on white oak 
twigs and leaves. 
