MONTANA EXPERIMENT STATION. 



169 



THE SCURFY BARK LOUSE. 



The scurfy l-ark louse is an elongated insect similar in shape to 

 the oyster shell bark louse but the substance of the scale is thinner 

 in texture and white in color. (See the accompanying figure). 

 . The winter it passes as eggs closely packed under the scale. The 

 eggs number from thirty to seventy-five and are of a reddish purple 

 color. In the climate of northern United States there is but one 

 brood. The eggs hatch in the spring and by fall the life cycle, 

 which is similar to that of the oyster shell louse, is completed. 



This species is not very liable to be introduced on nursery stock. 

 The white color of the scales renders them conspicuous objects and 

 the nurseryman who desires his trees to have a clean healthy ap- 

 pearance will usually notice them and remove them before shipping. 

 The oyster shell bark louse, on the other hand, is not noticeable, its 

 color being similar to that of the bark. 



Fig. 17, Skurfy bark-louse: a, c, females; o, d, males; a, b, natural size;. 

 c, d, enlarged. (Howard, Year-book, U. S. Dept. of Agr.) 



