Leafhoppers
Cicaclellidae homalodisca coagulata (Say), Oncometopia orbona (Fab.), Cuerna costalis (Fab.), and Aulacizes irrorata (Fab.)

Morris, R.C.; Filer, T.H.; Solomon, J.D.; McCracken, Francis I.; Overgaard, N.A.; Weiss, M.J. 1975. Insects and Diseases of Cottonwood. Gen. Tech. Rep. SO-8. New Orleans, LA: U.S. Dept of Agriculture, Forest Service, Southern Forest Experiment Station. 41 p.

Four species of large leafhoppers injure young cottonwood trees by piercing plant tissues with their mouth parts and sucking the juices. Heavy feeding removes large quantities of sap from the trees, and this loss of sap can be especially harmful during dry periods in midsummer, when foliage is heavy. In addition, three of the four leafhoppers are known vectors of the virus causing Phony Peach Disease and may carry other viruses to cottonwoods.

There is an obvious sign of leafhopper activity: leaves below the feeding sites may be wet by fluid squirted from the leafhoppers.

Homaladisca coagulata on cottonwood terminal. Photo by James Solomon, USDA Forest Service

Adult leafhoppers are about 1/2 inch (12 mm) long, bullet-shaped, and have strong jumping legs. The two species most common in midsummer are H. coagulata, which is brown. and 0. orbona, which is blue with orange markings.

All four species spend the winter as adults or occasionally as nymphs under trash and debris in woodlands and along ditchbanks. In spring they become active, leave the woods, and feed on a variety of plants. Later they move to preferred herbaceous plants. Females lay eggs in clusters between the upper and lowef leaf surfaces. The nymphs feed on various hosts during their development through five stages to the adult form.

No natural controls are known, but there are some approved chemical controls.