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| A leafhopper, Graphocephala sp. (Homoptera: Cicadellidae). Photo by C. L. Barr. |
Leafhoppers are insects belonging to the family Cicadellidae in the order Hemiptera. They are recognized by their piercing-sucking mouthparts and by the presence of rows of spine-like setae (hairs) in their hind tibiae.
Leafhoppers go through incomplete metamorphosis in their development. Female leafhoppers insert tiny eggs in tender plant tissue, causing pimplelike injuries. Overwintered eggs begin to hatch in mid-April. Wingless nymphs emerge and molt four or five times before maturing in about 2 to 7 weeks. Nymphs resemble adults except that they lack wings; later-stage nymphs have small wing pads. Leafhoppers overwinter in the Gulf States and migrate north each year. They usually arrive in New Jersey in June. There are two to three generations per year in New Jersey.
Leafhopper feeding causes leaves to appear stippled, pale, or brown, and shoots may curl and die. Some species cause a diamond-shape yellowing from the leaf tip. A few species secrete honeydew on which foliage-blackening sooty mold grows. Black spots of excrement and cast skins may be present on leaves and/or fruit. Some leafhopper species transmit plant diseases, but this is troublesome mostly among herbaceous crop plants.
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| Potato Leafhooper Empoasca fabae Life Cycle - University of Kentucky |
Leafhoppers can carry the bacterium, Xylella fastidiosa, which causes bacterial leaf scorch in elms, oaks, maples, and sycamores. Leafhoppesrs can also carry a phytoplasma which causes the disease known yellows, ash yellows affects ash, and elm yellows affects elms. Aster yellows affects coneflower, Echinacea. Aster yellows is spread from plant to plant by the leafhopper, Macrosteles phytoplasma. Once infected, diseased plants should be promptly removed and discarded to reduce further spread.
Managment Strategies
On maple, look for leafhoppers on the leaf underside. Look for stippling of leaves and curled or stunted shoot tips. Inspect trees regularly looking for leafhoppers feeding on the lower surface of leaves. Look also for distorted or stunted growth and yellow leaves.
Remove plants exhibiting the scorch-like symptoms or the distorted and stunted growth of aster yellows.
Avoid over fertilization, which may cause populations of leafhoppers to increase. ‘Autumn Blaze’, a hybrid of silver and red maple, is highly resistant.
Spray where needed, concentrating on regions where leafhoppers prefer to feed, particularly on new growth.
Bigeyed bugs, damsel bugs, assassin bugs and lacewings are common predators of leafhoppers.
Precautionary Statement on Pesticide Use
All pesticides have both benefits and risks. Benefits can be maximized and risks minimized by reading and following the labeling. Pay close attention to the directions for use and the precautionary statements. The information on pesticide labels contains both instructions and limitations. Pesticide labels are legal documents, and it is a violation of both federal and state laws to use a pesticide inconsistent with its labeling. Always read and follow the label.
Additional Information
Leafhoppers Fact Sheet 237 - NJAES - Rutgers University
Leafhopper - Department of Entomology - Texas A&M University
Potato Leafhopper on alfalfa - Penn State University
Virginia Alfalfa IPM Source - Virginia Tech
