Jassids vs Leafhoppers: How to Tell Them Apart in Crops

Jassids are leafhoppers. “Jassidae” is an old family name, and the USDA National Agricultural Library thesaurus now lists it as a synonym of Cicadellidae, the leafhopper family. So the jassid vs leafhopper question is not about two different insects: in cotton, “jassid” usually means one small leafhopper, the two-spot cotton leafhopper (Amrasca biguttula), whose adults are 2.1 to 2.7 mm long (UF/IFAS).

This guide shows how to tell the cotton jassid apart from other leafhoppers in the field, what the damage looks like, and the action thresholds extension services publish. It also has a scouting calculator you can use with your own counts.

What are jassids?

The word comes from Jassidae, an old family name for leafhoppers. The USDA thesaurus lists Jassidae, leafhoppers and sharpshooters under one preferred name, Cicadellidae. The old name survives as a common name, for example in cotton.

In cotton, the insect meant is Amrasca biguttula. It has many names. UF/IFAS lists it as the two-spot cotton leafhopper, and lists Amrasca devastans and several Empoasca and Chlorita names as older synonyms. Plant Health Australia calls it the green cotton jassid, under the name Amrasca devastans. In US extension notes from 2025 and 2026 it is simply “the cotton jassid”.

It belongs to the subfamily Typhlocybinae, tribe Empoascini. That is the same group as the potato leafhopper (Empoasca fabae), the tea green leafhopper (Empoasca onukii) and the Australian cotton leafhopper (Amrasca terraereginae). These insects look alike to the naked eye, which is the root of the confusion.

Why the name matters for US and Australian growers

The cotton jassid is now a pest in the US Southeast. Alabama Extension reports that it was first detected in the US Virgin Islands and Puerto Rico in 2023 and in Jackson County, Florida, in late fall 2024. A UF/IFAS and Auburn note from April 2026 says that, after a local find in early July 2025, it was found in about 115 counties in Florida, Alabama, Georgia and South Carolina within about four weeks. By the end of 2025 it had also been found in Louisiana, Mississippi, North Carolina and Texas.

Plant Health Australia’s fact sheet treats the cotton jassid as an exotic pest. Plant Health Australia asks growers who suspect it to call the Exotic Plant Pest Hotline (1800 084 881) before spraying. The native Australian cotton leafhopper is a different species, and NSW DPI describes its economic impact as intermittent.

Jassid vs leafhopper: what is really different

Because every jassid is a leafhopper, the useful comparison is between the cotton jassid and the other leafhoppers you are likely to find in the same crops. The table compares six of them using extension and journal descriptions.

Three points stand out. First, size does not separate a jassid from “a leafhopper”: the cotton jassid, potato leafhopper and beet leafhopper are all about 2 to 3 mm. Second, the two black spots are the best field mark for the cotton jassid, but UF/IFAS notes that photos are only a guide and that firm identification needs a microscope look at adult males or a DNA test. Third, some leafhoppers matter mainly because they spread disease, while the cotton jassid and potato leafhopper do their harm by feeding. Plant Health Australia states that the cotton jassid is not known to transmit any virus.

Behaviour is not a reliable test

A common claim is that jassids walk sideways while leafhoppers jump away. In fact, sideways walking is not unique to jassids. Iowa State University describes potato leafhopper nymphs walking away sideways or backwards when disturbed. Iowa State and the University of Missouri describe potato leafhoppers moving sideways, jumping or flying away when disturbed. Use spots, colour, crop and a hand lens instead.

Chart

Four common crop leafhoppers are about 3 mm long

Adult length in mm: upper end of the published range, or the stated typical length; selected species

Jassid or other leafhopper: how to tell them apart in the field

You can sort most samples into “possible cotton jassid” or “other leafhopper” in a few minutes. Keep a 10x hand lens and a few vials in the truck.

1. Look under the leaves. Adults and nymphs of all these species feed on leaf undersides. In cotton, Alabama Extension advises checking the mainstem leaf about four nodes below the terminal.
2. Check the size. If the insect is clearly longer than about 5 mm, it is not a cotton jassid. Large leafhoppers such as sharpshooters reach about half an inch.
3. Look for the two black spots. Adult cotton jassids have a black spot near the tip of each forewing and two small spots on the head. Older nymphs show dark dots on the wing pads; young nymphs cannot be named by sight.
4. Note the crop and the damage. Hopperburn on cotton, okra or eggplant in the US Southeast points to the cotton jassid. V-shaped yellowing on alfalfa, soybean or potato in the Midwest points to the potato leafhopper.
5. Confirm with a lab. Collect adults, ideally males, and send them to your state diagnostic lab or extension office (in Florida, UF/IFAS says regulatory IDs are confirmed by FDACS-DPI). In Australia, report suspected exotic jassids to the hotline.

Leafhopper and jassid damage symptoms

Leafhoppers feed on plant sap with piercing mouthparts. UF/IFAS explains that hopperburn is thought to come from toxins in their saliva together with the plant’s own response. The damage builds in stages.

• Early: faint yellowing or bronzing of the leaf (Alabama Extension).
• Middle: leaf edges curl, and margins turn yellow or red. This is the classic hopperburn on cotton.
• Late: leaves brown, dry out and drop, and the plant may be stunted.
• Potato leafhopper: Iowa State describes V-shaped yellowing at leaf tips, then wrinkling, cupping and stunting.
• Beet leafhopper: UC IPM describes white to yellowish stippling on leaves, plus the risk of curly top virus.
• Honeydew: UF/IFAS notes that cotton jassid honeydew can support sooty mould.

Iowa State notes that potato leafhopper injury is sometimes mistaken for herbicide injury or a nutrient deficiency, and that dry, stressed fields show worse injury. Always find the insect before you decide on a cause.

▶ How to spot leafhopper damage early and the field steps that keep it in check · 16:53

Cotton jassid life cycle

Short generations explain why counts can rise quickly. Alabama Extension says eggs hatch in 3 to 4 days, with five nymph instars over 8 to 10 days, adults that live 2 to 4 weeks, and a new generation about every two weeks. Lab studies give longer egg stages: 5 to 7 days in the studies compiled by UF/IFAS, and 8 to 10 days in Plant Health Australia’s fact sheet. Females insert their eggs into or near leaf veins, so the eggs are rarely seen.

Lab studies compiled by UF/IFAS show how much these stages vary with the host plant. On sunflower, egg to adult took about 22 days; on okra, one study measured about 14 days and another about 23 to 24 days. The studies were run at room temperature that was not recorded, so treat them as a range, not a forecast.

Chart

Cotton jassid stage length in three lab studies (sunflower and okra)

Mean days per stage, egg to 5th nymph instar, three lab studies

Cotton jassid threshold: when to act

An action threshold is the pest level at which treatment is likely to pay. For the cotton jassid, US thresholds are new and still changing. Alabama Extension reports that the preliminary threshold fell during 2025, as more field observations came in, from 5 nymphs per leaf to 3, then 2, then 1 to 2, and finally 1. The April 2026 UF/IFAS and Auburn note gives a working threshold of about 1 jassid per leaf, or early injury in the field. Where spraying may be delayed by acreage or equipment limits, it suggests treating when about 30 to 50% of sampled plants are at threshold. Alabama Extension gives the example of sprayers that can only cross each field every 10 to 14 days.

Chart

How the preliminary cotton jassid threshold fell in 2025

Nymphs per leaf at which treatment was advised, in order of revision (an interim 1 to 2 step is not shown)

Sampling matters as much as the number. The same note advises sampling at least 25 mainstem leaves per field, three to five nodes below the terminal, and counting nymphs on the leaf undersides at least once a week. Populations often start on field borders and on isolated plants.

The cost of waiting can be real. Across 18 trials reported by UF/IFAS and Auburn, untreated cotton jassid infestations caused an average yield loss of about 13%, with a range from 1% to 46% depending on timing and severity (UF/IFAS and Auburn, 2026).

Try the numbers for your own farm below.

Potato leafhopper thresholds in alfalfa and soybean

Thresholds differ by insect, crop and growth stage, so a cotton jassid number cannot be used for alfalfa, and the reverse. Alfalfa thresholds use the average number of leafhoppers per sweep with a 15-inch net. University of Wisconsin guidance (2020) is to treat at more than 0.2 per sweep on 3-inch alfalfa, 0.5 on 6-inch, 1.0 on 8 to 11-inch and 2.0 on alfalfa taller than 12 inches. An older University of Missouri table (2008, revised 2012) gives three times higher thresholds for leafhopper-resistant alfalfa varieties.

Chart

Resistant alfalfa tolerates about three times more leafhoppers

Potato leafhopper threshold, adults and nymphs per sweep, by alfalfa stem length

For soybean, Iowa State suggests treating vegetative fields when leafhoppers exceed two per plant, and flowering fields when they exceed one per trifoliate leaf.

Leafhoppers that spread disease

For vectors such as the beet leafhopper, counts are a poor guide. UC IPM states that treatment thresholds for beet leafhopper in potato have not been set, and it advises weed control in and around the field. For the glassy-winged sharpshooter, UC IPM notes there is no cure for the diseases its bacteria cause.

How to manage jassids and leafhoppers

Integrated pest management combines scouting, cultural steps, natural enemies and, when a threshold is reached, a well-chosen insecticide. The points below come from the extension sources named in this guide.

• Plant early and short. Alabama Extension suggests early planting and short-season, fast-maturing cotton varieties to shorten the time the crop is exposed.
• Balance fertility. The same source notes that excess nitrogen makes cotton more attractive to jassids, and potassium-short plants seem to tolerate injury less well.
• Use hairy varieties where they exist. UF/IFAS notes tolerance in some cotton, okra and eggplant lines, mainly linked to longer and denser leaf hairs.
• Protect natural enemies. In its native range, generalist predators and egg parasitoids attack the cotton jassid, though UF/IFAS says little is known about its enemies in Florida. The UF/IFAS and Auburn note advises conserving beneficial insects early in the season.
• Rotate crops and control weeds. Plan crop rotation with your other pests in mind, and keep weeds down in and around fields, as UC IPM advises for the beet leafhopper.
• Choose and rotate insecticides with care. In trials reported by UF/IFAS and Auburn, pyrethroids such as bifenthrin gave limited or inconsistent cotton jassid control, and UF/IFAS reports that resistance to many classes is common where the pest is native. Rotate modes of action, check your state production guide for registered products, and follow the product label and local rules.

These steps are part of wider crop protection. If you also deal with other crop pests, combine the scouting trips so each field is checked once a week.

Jassids in tea

Tea growers also use the word jassid. In East Asia, the main tea leafhopper is Empoasca onukii. A 2015 study in PLoS ONE examined at least 180 specimens from 18 Chinese provinces and regions and found that the insect called Empoasca vitis in China and Jacobiasca formosana in Taiwan is the same species known as E. onukii in Japan. The authors describe it as one of the dominant tea pests of East Asia, citing average annual yield losses of 15 to 50% in mainland China and Taiwan.

▶ How jassids damage tea bushes and the pest management options tea growers use · 7:57

Where satellite monitoring fits

Satellites cannot see a 3 mm insect. What they can show is a change in plant vigour across a field. The European Space Agency’s Sentinel-2 satellites, for example, give 10 m images with a 5-day revisit time. A patch that loses vigour faster than the rest of the field is a place to scout first, and the cause may be leafhoppers, other pests, drought or a nutrient problem.

The Farmonaut Satellite + AI Farm Monitoring System maps these changes across large areas of farmland, so scouts can go to the right corner of the field. The field check with a hand lens is still what confirms a jassid problem. You can see the crop monitoring system in our web app tutorial, open it from the app redirect page, or use the app on Android or iOS. Developers can read the API documentation and developer docs.

How we checked the numbers

We used extension services and journals only. Insect names and sizes come from UF/IFAS, Iowa State, UC IPM, NSW DPI, Plant Health Australia and a PLoS ONE study. Cotton thresholds, spread and yield loss come from Alabama Extension (October 2025) and a UF/IFAS and Auburn note (April 2026). Alfalfa thresholds come from the University of Wisconsin (2020) and University of Missouri (2008, revised 2012). Cotton jassid thresholds are preliminary and may change, so check your state guide before acting.

FAQ

What does jassid mean?

It is a common name for leafhoppers that comes from the old family name Jassidae. In cotton it usually means the two-spot cotton leafhopper, Amrasca biguttula, a 2 to 3 mm green insect that feeds on cotton, okra, eggplant and sunflower.

Is a jassid the same as a leafhopper?

Yes. Every jassid is a leafhopper. The useful question is whether a given leafhopper is the cotton jassid or another species, such as the potato leafhopper or beet leafhopper.

How do I tell the cotton jassid from the potato leafhopper?

Both are about 2 to 3 mm and green. The cotton jassid has a black spot near each forewing tip and two on the head; the potato leafhopper has six white spots behind the eyes. A lab can confirm the species from adult males.

What is the threshold for jassids in cotton?

The April 2026 UF/IFAS and Auburn working threshold is about 1 jassid per leaf, or early injury in the field, based on at least 25 mainstem leaves. It is preliminary, so check your state guide.

Do jassids spread plant viruses?

Plant Health Australia states that the cotton jassid is not known to transmit any virus. Some other leafhoppers do spread disease, such as the beet leafhopper (curly top virus) and the glassy-winged sharpshooter (Xylella bacteria).

Summary

A jassid is a leafhopper, and in cotton the word usually means Amrasca biguttula. Use the two black spots, the crop and the damage to separate it from other leafhoppers, confirm with a lab, and act on counts against the threshold for your crop. Good scouting and careful insecticide use are part of the wider future of sustainable agriculture.

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