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How to identify it
Where it lives
Curly top, the virus it spreads, is common in the western United States from Mexico to Canada. Utah State says the leafhopper overwinters as mated females on weeds and uncultivated land in the southern U.S. and migrates or is blown north in early summer; in southern Idaho it moves from rangeland and weedy breeding areas into crops any time from early May to the end of August.[3][1][2]
Biology and life cycle
When the weeds it overwinters on dry up, adults move into fields and gardens to feed and breed, and wind can carry them long distances. There are several generations a year, and development from egg hatch to adult takes about 2 to 3 months.[1][2]
It picks up curly top virus by feeding on infected weeds in spring. The virus survives in weeds such as Russian thistle (tumbleweed) and mustards like London rocket and flixweed.[1][3]
An infected leafhopper can pass the virus to a healthy plant in a few minutes of feeding and remains able to spread it for life (Idaho notes more than three months), but it does not pass the virus to its offspring.[1][2][3]
The virus infects more than 300 plant species in 44 families, apparently only broadleaf plants. Common hosts include tomatoes, peppers, beets, Swiss chard, beans, potatoes, spinach, squash, melons, cucumbers, cabbage, alfalfa and many ornamentals.[3][2]
Damage and signs
- Heavy feeding by adults and nymphs can shrivel and burn leaves, a condition called hopper burn, but the most severe damage to tomatoes and peppers comes from the curly top virus it transmits.[1]
- On tomatoes and peppers, infected leaves turn thick, stiff and crisp and roll upward while the leaf stems curve down; the leaves yellow and may show purplish veins. Beet leaves become very twisted and curly.[3]
- Young plants infected early often die soon after. Plants infected later survive but stay yellow and stunted, yield drops, and fruit ripens early; dull, wrinkled, immature tomato fruit is a good sign of curly top. Symptoms can appear within 24 hours in high summer heat, in 12 to 14 days at average temperatures, or in up to 30 days when it is cool.[3]
- New Mexico State finds the disease particularly troublesome in home gardens, possibly because weeds the leafhoppers prefer and infected source plants are close by.[3]
- In sugar beet fields, severe outbreaks can cut yields by 30 percent or more.[2]
Health risk
The beet leafhopper feeds only on plants. Utah State, Idaho and New Mexico State treat it as a crop and garden pest because of the virus it spreads and mention no risk to people or pets.[1][2][3]
Control
Prevention
Keep weeds down in and around the garden or field, and clear away plant debris and volunteer plants from earlier crops. Weeds and volunteers can harbor both the leafhoppers and the virus over winter.[1][3][2]
Leafhoppers prefer to feed in sunny spots, so New Mexico State suggests growing tomatoes and peppers in a slightly shaded part of the garden.[3]
Utah State reports that the resistant-labeled tomato varieties 'Rowpac', 'Roza', 'Salad Master' and 'Colombian' performed well in trials in St. George, Utah, and that planting more densely than normal lowers the odds that every plant is infected. New Mexico State says true resistance to curly top is not known, but planting several cultivars may help because some may be somewhat tolerant.[1][3]
Keep them out
Cover young plants. Utah State suggests floating row covers; New Mexico State suggests a netted cage over young plants in full sun, with holes small enough to keep leafhoppers out and the netting kept off the plant. Remove cages once plants mature, since mature plants are less susceptible and need the light to develop fruit.[1][3]
Sanitation
Pull out plants with curly top as soon as you notice them so they stop serving as a source of the virus. No chemical controls the virus itself.[3]
Biological control
Few natural enemies are known. A parasitic fly (family Pipunculidae) attacks beet leafhoppers, but how much it reduces their numbers is unknown.[1]
Pesticides
Insecticides are hard to use well against this pest because of its wide host range, long migrations and fast virus transmission. Sprays may stop some spread within a field and are mostly aimed at weed hosts to keep leafhoppers from moving into the crop, but the results are often costly and less than ideal, so cultural control is the main approach. In sugar beets, tolerant varieties and insecticide seed treatments are the common tools.[1][2]
Common questions
- Why are my tomato leaves curling up, turning yellow and getting stiff?
- That pattern fits curly top, a virus spread by the beet leafhopper. Infected tomato leaves thicken, roll upward and yellow, often with purplish veins, and the fruit ripens early and looks dull and wrinkled. No chemical cures the virus, so pull infected plants promptly.[3]
- Can I spray for beet leafhoppers to stop curly top?
- Spraying gives poor results. The leafhoppers feed on many hosts, migrate in from weedy areas and can infect a plant within minutes, so Utah State relies mainly on cultural steps such as weed control, row covers and resistant varieties.[1]
- Does covering my plants help?
- Yes. Floating row covers or a netted cage over young plants keep leafhoppers from feeding. Keep the netting off the leaves and remove cages once plants mature.[1][3]
Sources
- Utah State University Extension, “Beet Leafhopper (Circulifer tenellus), Utah Vegetable Production and Pest Management Guide.” extension.usu.edu/vegetableguide/tomato-pepper-eggplant/beet-leafhopper (accessed 2026-11-08)
- University of Idaho Extension, “Beet curly top virus (Pest Management: agricultural pests).” www.uidaho.edu/extension/food/ipm/ag-pests/beet-curly-top (accessed 2026-11-08)
- New Mexico State University, College of Agricultural, Consumer and Environmental Sciences, “Curly Top Virus, Guide H-106 (revised by N. Goldberg and P. Lujan).” pubs.nmsu.edu/_h/H106/ (accessed 2026-11-08)
- iNaturalist, “Neoaliturus tenellus taxon page (order and family).” www.inaturalist.org/taxa/482589 (accessed 2026-11-08)