By Francesco Pacelli,
Nursery Technical Analyst

Leafhopper is a common name applied to any species from the family Cicadellidae. Leafhoppers belong to one of the largest families of plant-feeding insects. There are more leafhopper species worldwide than the combined species of birds, mammals, reptiles and amphibians.

Leafhoppers feed by sucking the sap of vascular plants. They are found almost anywhere these plants occur, from tropical rainforests to Arctic tundra. Several leafhopper species are major agricultural pests. Many leafhoppers are handsomely coloured and patterned, while others are camouflaged green to blend with foliage. When disturbed, they run in a sideways motion (especially nymphs). As the name implies, they also leap from plant to plant, although adults can fly. The leafhoppers are divided into about 40 subfamilies.
 

Adults

Leafhopper adults are elongated, wedge-shaped and somewhat triangular in cross-section. They jump and fly off readily. Depending on species, they range in size from 2.5 to 3.4 mm and their bodies are yellow, green, gray, or they may be marked with colour patterns. Nymphs resemble adults, but are wingless. They can run rapidly, occasionally sideways, and hop.
 

Eggs

Eggs are laid on leaves or stems in the upper part of the canopy and hatch in about 10 days. Eggs are yellowish and curved and cylindrical with tapering ends and creamy white in colour, less than 1 mm in length. Generally, the shape of the egg depends on the species of leafhopper.
 

Life cycle

Most species over-winter as eggs. They are inserted into leaf veins, shoots or stems of host plants. Wingless nymphs hatch from eggs in about 10 days and begin feeding on the tender new growth of their host plant. They develop through five stages (instars) over a period of 12 to 30 days, leaving shed skins in the feeding area. As nymphs grow larger, they develop wing pads. Most leafhoppers produce one generation per year, but some may develop up to six. Some species, such as potato leafhoppers, do not over-winter in Ontario. Each spring adults are carried by wind currents from the southern Gulf states and across the Great Lakes into Ontario. The first adults arrive as early as mid-May and continue to arrive well into June.
 

Habitat and food source

Species can be somewhat specific to certain host plants. As a whole, leafhoppers feed on leaves of a wide variety of plants, including many types of grasses, flowers, vegetables, fruit trees, shrubs, deciduous trees  and weeds. The rose leafhopper, Edwardsiana rosae (Linnaeus), feeds primarily on plants of the rose family, although foliage of other woody plants (blackberry, Cornus, oak, Prunus, Populus, raspberry, Ulmus, Acer and others) serve as food. The potato leafhopper, Empoasca fabae (Harris), feeds on legumaceous plants like alfalfa, as well as apple, birch, chestnut, maple and others. Species in the genus, Erythroneura, feed on sycamore leaves, as well as apple, grape and willow. The aster, or six-spotted leafhopper, Macrosteles quadrilineatus (Forbes) feeds on vegetables and annual flowers and spreads the aster yellow virus to woody plants like periwinkle and Thunbergia species.The honey locust leafhopper Macropsis fumipennis feeds on Gleditsia species. Nymphs and adults feed on the underside of leaves. Some leafhoppers are readily attracted to lights.
 

Pest status, damage

Species with sucking mouth parts occasionally injure plants and transmit plant diseases. Skins from developing nymphs are commonly associated with an infestation. Removal of sap from the mesophyll or vascular tissues (phloem and xylem) and injection of toxic salivary secretions (e.g., proteinaceous fluid clogs in the vascular tissues) during feeding activity. This causes leaves to develop yellow or clear stipples, spots or leaf portions that are visible on the upper leaf surface. Yellowing and browning of injured leaves is often called ‘hopperburn’ or ‘tip burn.’ Injured leaves can fall prematurely. Some species cause terminal growth of injured plants to become curled and stunted. Heavily injured plant parts or plants can die. Egg-laying habits can also cause some plant injury.
 

Monitoring

Yellow or orange sticky traps can be used to monitor leafhoppers. Traps must be checked daily, so that rapid changes in the population can be detected. Timing is critical for this pest. The sticky trap method is effective to detect major increases in the leafhopper population.
 

Chemical control

The most commonly used chemical pesticides are APM 50 W, Guthion 50 WP, Sniper 50 W (with a minimum re-entry period of 48 hours), Methoxyclor 240 EC, Orthene, Pyrate 480 EC, Sevin XLR plus, Imidan 50 WP, Tristar 70 WSP.
 

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Francesco Pacelli may be reached at fpacelli@landscapeontario.com.

Captions:
Leafhopper nymph.
Leafhopper