COCCIDM 137 



San Jose Scale.— The San Jose scale is an introduced 

 species which has been the source of an immense amount of 

 loss in orchards, nurseries, etc. It presents some modifica- 

 tions from the ordinary forms. It is small with an almost 

 perfectly circular scale. The exuviae remain near the centre, 

 giving it a somewhat nipple-shaped appearance. When 



Fig. 90. — San Jose scale; male adult — greatly enlarged. (After 

 Howard.) 



abundant they give a very scurfy incrusted appearance to 

 the twig on which they occur. The male scales are smaller 

 .and a little more oval in shape. The life history differs from 

 most other species in that young are produced alive, the 

 eggs hatching before extrusion, and the young develop 

 rapidly, mature in a short time, and produce another genera- 

 tion. There may be as high as four to six generations in a 



