88 



ENTOMOLOGICAL SOCIETY OF ONTARIO. 



having been first described by the late J. Duncan Putnam, from Iowa. It is known to 

 occur on the following plants also, ash, beech, bladder-nut, hackberry, linden, oak, osage- 

 orange and water locust. This is often mistaken for the San Jose scale, even by those 



Fig. 83.— San Jose' Scale, female enlarged and part of infested branch (life size.) 



who are quite familiar with the latter. My own manner of distinguishing between these 

 two scales is to first observe if the disc is circularly wrinkled and the elevation in the 

 centre surrounded by a depressed ring ; if the scale is very flat, or if it appears to rise 



UUtixg. 



Fig. 84. 



gradually from the outer edge to the base of the elevation ; if the scales are disposed to 

 crowd in compact patches. If the disc is circularly wrinkled with a deeper ring about 

 the base of the elevation ; if the scales crowd each other closely and give the tree a gray 



