144 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
Eggs are laid on the leaves in May and June. After two molts the 
young nymphs migrate in the fall from the leaves to twigs and branches, 
and hibernate there throughout the year. (For control measures, see 
p- 36.) 
The cottony maple scale (Pu/vinaria vitis L.) is larger than the 
maple leaf scale, being from 5 to 7 mm. long and about 4 mm. wide. 
It is brown in color and elongate-oval in shape. It is conspicuous in 
summer, owing to the large. white, cottony egg sac extruding from the 
poster ior end of the body. The species is widespread over the United 
States and southern Canada and attacks many species of trees, includ- 
ing most of the maples, boxelder, white ash, black locust, syeamore, 
red mulberry, and the Japanese angelica tree (Avra/ia elata Seem.). 
Eggs are laid from April to June and hatching takes place through- 
out the summer. U pon hatching, most of the nymphs migrate to the 
undersurface of leaves, where they feed on the principal veins. Some 
migrate to the upper surface of leaves; others remain on the twigs. 
Nymphs complete their development by fall, and after fertilization 
the adult females migrate to the twigs. where they overwinter and 
remain in the spring ‘to produce their characteristic egg masses (fig. 
32). There is one generation annually. 
Heavy populations of this scale seldom occur on the same trees for 
two successive years, owing to the numerous predaceous and parasitic 
insects that attack it when it is numerous. However, it sometimes 
becomes so abundant in 1 year, especially on shade trees, as to require 
the application of control measures (p. 36.) 
The woolly pine scale (Pseudophilippia quaintancii Ckll.), char- 
acterized by the presence of heavy white woolly masses at the bases of 
new-growth needles. may be found on loblolly, mugho, pitch. and long- 
leaf pines from New England and New York to Florida and Louisiana. 
Apparently only young trees below 14 feet in height are attacked 
(Felt, 247, pp. 689-690). 
The magnolia scale (Neolecanium cornuparvum (Thro)) is the 
largest scale insect found in the United States, the adult female measur- 
ing r about 1 4, inch across. It is a rich dark brown and nearly round, 
when uncrowded (fig. 33). It attacks several species of magnolia. 
Herrick (222) mentioned that excessive infestations cause serious 
injury to its host. 
The tuliptree scale (7oumeyella liriodendrvi (Gmel.) ), only a little 
smaller than the magnolia scale, occurs over the eastern half of the 
United States and attacks yellow poplar, magnolia, bay, and cape- 
jasmine. Females are dark ‘brown, hemispherical, and are fr yi! 
found in crowded masses on twigs and branches of the host (fig. 34). 
Houser (239, pp. 301-302) discussed this insect and the awe 
caused by it. 
In the northern part of the United States the pine tortoise scale 
(Toumeyella numismaticum (Pettit and McD.)) is found on Scotch, 
Austrian, and jack pines. Females of the species are reddish brown, 
oval, very convex, and from 5 to 7 mm. long. The species hibernates 
as immature females and has one generation a year. 
Pines heavily infested with the scale become covered with a black 
sooty mold, the foliage drop is unusually heavy, and the needles on 
the trees are much shorter than normal. Whole trees may die within 
a few years. Young trees are preferred hosts apparently, and the 
