INSECTS AFFECTING I'AKK AND WOODLAND TREES 211 



Oyster scale 

 LcpidosiXplics III mi Linn. 

 A brownish oyster shell-like scale, about 's inch long, may be found on a consider- 

 able number ot food plants tlunigh usually more al)undant on ash and balm of (iilead. 



This is one of our more common scale insects, well known to many 

 fruit oTowers because of its occurring on apple, pear and other trees pro- 

 ducing valuable fruits. It is also occasionall_\- ([uite abundant on some of 

 our forest trees and the writer has observed a number of cases where ash 

 saplings of considerable size have become literally incrusted with this 

 insect and died. It is sometimes nearly as abundant on balm of Gilead 

 and some poplars, though these trees do not as a rule succumb so readily to 

 attacks by this insect. This species has been noticed so many times that 

 only a brief summary of its life history and habits is ailvisable in this 

 connection. 



Description. The adult female scale is about 's inch long, usually 

 slightly curved and widening from a slender tip to a broad rotmded pos- 

 terior end. The scale has at its anterior end a yellowish very small pel- 

 licle, the lirst cast skin of the young, and the small scale three times its 

 size attached to it. There is usually a larger or second cast skin, to wliich 

 is attached the largest or chief part of the scale wdiich is of a variable 

 brown color marked with curved, transverse lines or wrinkles. The female 

 is found beneath the scale, and when ali\-e is a yellowish, legless, wino-jess, 

 eyeless form about ' [o inch in length. The female scale turned over in 

 winter will be found to contain a large number of minute whitish eggs, and 

 near its anterior end the shriveled yellow or brown body of the female 

 may be detected. The recently hatched young are very minute, yellowish, 

 and to the naked eye appear like specks \scc pi. 13, fig. 9-14]. 



Life history. This insect produces but one generation annualh' in the 

 northern states though in the south there may be two. The winter is 

 passed in the G.^g<g under the protecting scale of the female, and the young 

 appear from the middle of May to early fune, and in the case of badly 

 infested trees, parts of the twigs ma\- be literally )-ellow because of their 



