The whitebanded elm leafhopper lays its eggs in the cork parenchyma of elm 
bark. When the nymphs hatch, they wander in search of leaves on which to feed. 
The first of these to be found usually are on tiny branchlets growing from the trunk. 
A dozen or more young nymphs may be found clustered on the undersurface of one 
of these leaves, where they feed on the midribs or larger veins. Excessive feeding 
often causes the apical portions of the leaves to turn brown and die. Older nymphs 
are more widely distributed throughout the crown of the tree (44). 
Elm phloem necrosis mycoplasm is transmitted by the adults that feed first on the 
leaves of diseased trees and then on the leaves of healthy trees. Studies have shown 
that a period of several days must elapse after the insect feeds on a diseased tree 
before it can transmit the mycoplasm. Not all of the details of the life cycle of the 
species have been determined, but it is known that the winter is spent in the egg 
stage and that there is only one generation per year. 
Homalodisca coagulata (Say), Oncometopia orbona (F.), Cuerna costalis (F.), 
and Graphocephala versuta (Say) transmit the rickettsia causing phony peach, a 
destructive disease of peach trees in the South. 
Family Membracidae 
Treehoppers 
Treehoppers are characterized by the prolongation of the pronotum backward and 
above the abdomen. In some species it not only extends backward but also sidewise 
and upward, and in some, it extends to the top of the abdomen and completely 
covers the wings. The hindlegs are long and adapted for jumping, and the female’s 
ovipositor 1s long and sawlike. The majority of species apparently live on trees, 
most often in open stands but also in woods. Only a few species are of economic 
importance. The species of treehoppers found in Connecticut and Ohio have been 
discussed (456, 950). 
The buffalo treehopper, Stictocephala bisonia Kopp & Yonke, 1s occasionally 
injurious to young ash and elm trees. Injury results from two opposing slits cut in 
the bark by the female during oviposition. Eggs are placed in the slit, and the 
portion of the stem beyond it often dies. Adults are light green to yellowish and 
about 9 mm long. The pronotum is sharply elevated, is widest at the tip, bears two 
sharply pointed horns that extend at right angles to the body, and ends beyond the 
tip of the abdomen in a narrowed acute process. 
The threecornered alfalfa hopper, Spissistilus festinus (Say), occasionally 
damages black locust seedlings in nurseries in the South. Injury results from 
nymphs feeding on the stems, usually 25 to 50 mm above the base. Gall-like 
swellings or calluses that develop just above the feeding punctures kill many of the 
seedlings. Other seedlings are lost when they break at these points. Stictocephala 
militaris (Gibson & Wells) nymphs feed on the veins and petioles of sweetgum 
leaves in north Georgia. Gall-like enlargements may develop at points of injury on 
the petioles, or the leaves may die. Other common membracids and their tree hosts 
are as follows: Micrutalis calva (Say)—abundant on honeylocust; Telamona re- 
clivata Fitch—common to abundant on basswood; 7. decorata Ball—fairly com- 
mon on quaking aspen; Vanduzeea arquata (Say) and Thelia bimaculata (F.)— 
abundant on black locust; Cyrtolobus discoidalis (Emmons)—common on red oak; 
Carynota stupida (Walker)—sometimes abundant on yellow birch; Platycotis 
vittata (F.)—abundant on oak; and the twomarked treehopper, Enchenopa 
binotata (Say)—common on butternut but also attacks walnut. 
71 
