58 



THE REPORT OF THE 



No. 19 



The scale has been reported to us or found by us in very many places 

 in Collingwood on the west to Trenton in the east. 



Its chief food plants in Ontario seem to be the apple and pear. It is 

 said, however, to attack also the plum, cherry, currant, mountain ash, elm, 

 basswood, Carolina poplar, and willow. 

 Natural enemies : 



(1) A white fungus, commonly attacks it at Guelph. See Plate D. 



(2) A few of the scales were perforated in a manner characteristic of 

 Chalcid flies, so that it is probably attacked by one of these tiny parasites. 



Remedies : 



Scrape the rough bark off the trunks of trees and use the same remedies 

 as for San Jose scale. 



Fig. 16. Curtis Scale (Asiyidiotus ostrdjeformis), greatly magnified. 



Xx. 



B'iG. 17. Curtis Scale {Aspidiotus ostreaformis). (a) Young scales which are not nearly 

 full-grown; the nipple is plain, but the circular grove about it is wanting; (h) Full- 

 grown pregnant female ; the nipple is large ; (c) old scale with several young scales 

 hidden beneath it— a characteristic feature. 



