56 
Psyche 
[March 
entire terminal portion of the twig dies. This is apt to be 
of considerable importance on young trees that are used for 
ornamental purposes. 
A survey of the willows in the Arboretum showed that 
this species infests 53 named species and varieties of Salix. 
Almost every plant in the collection was infested. The in- 
festation varied somewhat in severity among the various 
plants, but this variation could not be attributed to any 
varietal difference. It was usually worse on the young plants. 
The geographical distribution of the origin of these plants 
is as follows: 
25 species and varieties native to Europe : 
11 species and varieties native to Europe and Northern Asia. 
8 species and varieties native to China. 
3 species and varieties native to Asia. 
3 species and varieties native to Japan. 
3 species and varieties native to North America. 
The chances are that this species will attack all of our 
native species of Salix and all the introduced ornamental 
species and that eventually it will become distributed 
throughout the country wherever willows are grown, unless 
measures for its control are undertaken now when it is 
limited to a small area in Eastern Massachusetts. 
Preliminary observations indicate that this spittle bug 
may be controlled by hydrated lime dust containing 4 to 6 
per cent of nicotine sulphate applied to the spittle masses. 
Description of Plate I. 
Figure 1, Twig of willow tree showing mature nymphs in 
individual masses of spittle. 
Figure 2, Large mass of spittle containing many nymphs. 
Figure 3, Same as Figure 2, not so much enlarged. 
