168 



TREES IN WINTER 



As a class, they secrete a waxy or scaly covering to their body 

 and for this reason are called scale insects. The 'scaly covering 

 of the San Jose species is circular in outline, either black or 

 gray in color, and about half the size of the head of a pin. That of 

 the oyster shell species is elongated, pointed at one end, either 



Fig. 89. The San Jose Scale. 



Fig-. 90. The Elm Scale. 



bro^vn or black in color, and about one-eighth of an inch in 

 length. The scurfy scale is somewhat fan-shaped, of a pale gray 

 color, parchment-like, and about one-eighth of an inch in length. 

 The tulip scale is much larger and more conspicuous, being- about 

 a quarter of an inch in diameter, hemispherical in shape, and dark 

 brown in color. The cottony maple scale also is a large and con- 



