346 Bulletin No. 112. [January, 



the insect, to review the attempts made to destroy it by means of 

 summer and winter sprays, and to present practical instructions 

 for its mastery where it is still present in destructive or threatening 

 numbers. 



A comprehensive article on the insect, prepared by Dr. L. O. 

 Howard, appeared in 1900 in Bull. 22 of the U. S. Bureau of En- 

 tomology, and Circular 64 of that Bureau gives a brief popular 

 account of it and of measures to be taken for its destruction. This 

 paper was prepared with special reference to the Chicago situation 

 of 1905. In Bull. 52 of the Bureau, published in 1905, is a paper 

 by Mr. H. E. Weed describing his experiences in spraying against 

 this scale in Chicago, and Mr. S. A. Johnson has reported on some 

 experiments in Denver, Col., with a winter insecticidal treatment. 

 The last-mentioned author has this year made the species the subject 

 of Bull. 116 of the Colorado Agricultural Experiment Station, in 

 which a summer treatment is especially discussed. 



Food PivAnts. 



The soft maple (Acer saccharinum) is the tree most generally 

 and heavily infested by this insect. The hard maples, on the other 

 hand, are infested but slightly if at all. The box-elder is also greatly 

 subject to injury, and next to this, perhaps, the linden or basswood. 

 Among the other trees and woody plants often more or less injured, 

 are the elm, honey-locust, black locust, black walnut, sumac, willow, 

 poplar, beech, hawthorn, bittersweet, grape-vine, and Viriginia 

 creeper. Dr. Folsom found mature egg-laying females on the horse- 

 chestnut, honeysuckle, dogwood, trumpet-creeper, mulberry, snow- 

 berry, smoke-tree. Spiraea, false syringa (Philadel^hus) , and Wis- 

 taria. Oak, ashj and catalpa are not infested in northern Illinois, 

 but injury to oak is reported from Georgia. According to S. A. 

 Johnson, the pear is most liable to injury among the fruit-trees, and 

 apple, plum, and peach are sometimes infested. Serious damage to 

 fruit-trees is, however, very unlikely. The migrating young, which 

 are often washed from trees by rain, or blown off in considerable 

 numbers, may maintain themselves for a time on a great variety of 

 woody and herbaceous plants, those on the latter, of course, per- 

 ishing with the advent of frosts. 



