INSECT ENEMIES OF EASTERN FORESTS 2 
which may be serious, that can be attributed to insects in this family 
is the slitting of twigs by ovipositing females for the placement of 
eggs. Both Ceresa bubalus (F.) and Stictocephala inermis (F.) are 
responsible. The three-cornered leafhopper (S. festina (Say), is re- 
ported to be injurious to black locust seedlings in nurseries. Injury to 
the seedlings results from feeding. A callus forms and a point of weak- 
ness develops that may either kill the seedling outright or cause it to 
break off when being pulled for planting. 
FIcuRE 20.—Treehoppers: A, Unusual and fantastic development of the pro- 
thorax of exotic species; B, front view of four species of treehoppers. All 
x 8. (From Comstock. ) 
Famity CERCOPIDAE 
The bodies of the spittle bugs are stout, oval, or elongate-oval (fig. 
21,4). There are two ocelli situated in the vertex between the eyes. 
The antennae are short and inserted between the eyes and below the 
margin of the vertex. The various species produce quantities of white 
froth or “spittle” (fig. 21, 6), from which the family derives its com- 
mon name, “spittle bugs.” 
Nearly all the species in the United States belong to the subfamily 
Aphrophorinae. They are rather dull colored, and feed on a variety 
of trees, shrubs, grasses, and cultivated plants. Most important from 
the standpoint of the forest entomologist is the genus Aphrophora 
(Stearns, 397). 
The pine spittle bug (Aphrophora parallela (Say)), a native of 
North America, is distributed from southern Canada and New England 
west to the Lake States and southwest to Missouri and Arkansas. 
