INSECTS AFFECTING PARK AND WOODLAND TREES I 77 



Description and habits. The yount; and adults occur here and tliere 

 over the leaves, there heiiii; no clusters, such as are so characteristic of the 

 Chaitophorus occurring- on the Norway maples. The winged adult is 

 yellowish green, and harmonizes very closely with the color of the veins 

 on the underside of the leaves. The very delicate; antennae have each 

 segment tipped with black. The dorsum of the thorax and of the anterior 

 abdominal segments is marked with inconspicuous brownish spots. There 

 are four small, black tipped tubercles on the dorsum of the anterior 

 abdominal segments. The honey tubes are very short. The wings are 

 nearly colorless, except for the light brown and greenish shades along the 

 veins. The wingless individuals are nearly the same color as the adults, 

 and are even less conspicuous. The thorax is spotted dorsally with 

 very small light brown markings [src pi. ii, fig. 12-14]. It frequently 

 happens that the best signs of this insect's presence are the numerous 

 whitish exuviae cast by the growing young. These cling to the leaves for 

 a considerable time, and give a very good idea of the previous abundance 

 of the insect. 



Remedial measures. Thorough spraying with a contact insecticide, 



taking special pains to make the application to the underside of the foliage, 



is a most efficient check on this species, though it is a costly method in the 



case of large trees. 



Bibliography 



1898 Lintner, J. A. Ins. X. Y. 13th Rep't. 1897. 11.362 



Woolly elm leaf aphid 



Schizoiiciira a)iicricaiia Riley 



Curled and gnarled leaves of white elm in June with wliitish pellets of honeydew 

 dropping from the trees, are characteristic of this plant louse. 



This insect is sometimes very abundant on American elms and fre- 

 quently the first indication of its presence is the whitening of foliage under 

 the infested trees, a disfigurement caused by falling wax-covered pellets 

 of honeydew. An examination of the elm usually shows that one side of 

 the leaf has turned under the other, forming a cavity which is frequenth- 



