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How to identify it
- Adults are mottled brown, aphid- or gnat-sized insects about 1/8 inch long; UC IPM gives 1/8 to 1/6 inch, with red eyes and short antennae. APHIS adds that the last two antenna segments are black and the abdomen can be blue-green, gray-brown or orange-yellow.[1][2]
- Adults feed head down with the body raised at almost 45 degrees, a posture no other citrus pest uses, and they jump or fly when approached.[1][2]
- Eggs are tiny, yellow-orange and almond-shaped, tucked into the folds of new leaves.[1][2]
- Nymphs are flat and yellow to orange, and each makes a curly white wax tube with a bulb at the end, a shape unique to this psyllid.[1][2]
Look-alikes
| Look-alike | How to tell them apart |
|---|---|
| Redgum lerp and other eucalyptus psyllids | UC IPM separates Asian citrus psyllid by its brown wing band broken by a clear patch, its tilted feeding posture and its nymphs' wax tubes.[1] |
| Eugenia psyllid | Another garden psyllid; it lacks the Asian citrus psyllid's interrupted wing band and body tilt.[1] |
Where it lives
It originated in eastern Asia or the Indian subcontinent. In the US it was first found in 1998 in Palm Beach County, Florida, on backyard orange jessamine, and in California in 2008; it has spread through Southern California and been found as far north as the San Francisco Bay Area and near Sacramento. APHIS reports the disease it spreads throughout Georgia, Florida, Mississippi, Puerto Rico and the U.S. Virgin Islands and in parts of Alabama, Arizona, California, Louisiana, South Carolina and Texas.[1][2]
Biology and life cycle
Females lay eggs in the folds of new citrus leaves, and each can lay several hundred over her life.[1]
Nymphs feed only on soft new growth and molt four times; adults typically live one to two months.[1]
Mature trees flush mostly in spring and fall, but young trees and lemons can flush year round in warm weather, giving psyllids places to breed.[1]
A psyllid picks up the bacterium by feeding on an infected plant and injects it into a healthy one as it feeds. Nymphs can pick it up and spread it as adults only weeks after a tree is infected, long before the tree shows symptoms.[1][5]
Damage and signs
- Nymphs inject a salivary toxin that twists, curls or kills new shoots and leaves notched leaves; their honeydew grows sooty mold. The psyllid alone damages leaves but doesn't kill trees.[1]
- HLB causes lopsided, blotchy yellowing of leaves, with green on one side of the leaf and yellow on the other. Fruit stays small and partly green, turns lopsided and bitter, and drops early, and trees get twig dieback.[1][2]
- APHIS says fruit from infected trees can only be sold for juice, and that the disease has devastated millions of acres of citrus in the US and abroad.[2]
- Hosts include all citrus and close relatives such as calamondin, box orange, Indian curry leaf and orange jessamine.[1][3]
Health risk
It feeds only on plants. APHIS says citrus greening poses no health threat to people or animals, and UC IPM says the fruit is safe to eat.[2][1]
Control
Prevention
Check new leaf flush monthly from spring through fall, walking slowly around each tree and looking for twisted or notched leaves, wax tubes, honeydew and adults.[1]
Buy citrus only from reputable local nurseries; APHIS says to buy only USDA-certified citrus plants.[1][2]
Keep them out
Know the quarantines in your area. Don't move citrus plants, branches, clippings or green waste out of a quarantined area, and don't mail or carry home-grown citrus fruit or plants out of one. In California's quarantine zones fruit may be moved only if it is washed and free of stems and leaves.[2][1]
Biological control
Tiny parasitic wasps such as Tamarixia radiata have been released in California and have reduced psyllid numbers, though not stopped HLB. Control ants on citrus trunks, because ants tend psyllid nymphs for honeydew and fend off their natural enemies.[1]
Pesticides
For home trees with psyllids, UC IPM lists oils and soaps (reapplied every 7 to 14 days), the systemic soil drench imidacloprid (1 to 2 months of nymph control) and foliar sprays; don't apply systemic or broad-spectrum products while trees bloom. APHIS calls intensive chemical control the main tool but costly and increasingly ineffective, and researchers have documented psyllids becoming less susceptible to several insecticides. Follow the label.[1][2][5]
When to call a professional
Report suspected psyllids in new areas or HLB symptoms anywhere: APHIS directs reports to your State Plant Health Director, and in California UC IPM gives the CDFA Exotic Pest Hotline (1-800-491-1899) or the county agricultural commissioner. Infected trees must be destroyed.[2][1]
Citrus greening quarantines
Federal regulated articles for the psyllid and citrus greening include all plants and plant parts, including leaves but not fruit, of citrus, kumquats, trifoliate orange, Murraya (orange jessamine), curry leaf and a list of other citrus relatives.[3]
Texas, for example, quarantines four areas for citrus greening: the Gulf Coast area (Brazoria, Fort Bend, Galveston, Harris and Montgomery counties), the Coastal Bend area (Aransas, Calhoun, Kleberg and Nueces counties), the Valley area (Brooks, Cameron, Hidalgo, Jim Hogg, Kenedy, Starr, Willacy and Zapata counties) and Webb County.[4]
Quarantine maps change as new finds are made, so check the current map with your state department of agriculture or APHIS.[2][4]
Where sources disagree
How fast HLB kills: UC IPM says it can kill a tree in as little as 5 years, while APHIS says most infected trees die within a few years.[1][2]
When symptoms show: UC IPM says it takes one to several years after infection, or 2 or more years in mature trees, and Grafton-Cardwell and colleagues describe a long latent period that lets the pathogen spread widely before it is detected.[1][5]
Common questions
- How can I tell an Asian citrus psyllid from other bugs on my citrus?
- Look for a tiny mottled brown insect feeding head down with its rear raised at about 45 degrees, and for nymphs making curly white wax tubes on new leaves.[1][2]
- Can citrus greening be cured?
- No. There is no cure, so infected trees are removed and psyllids are controlled to slow the spread.[1][2]
- Is fruit from an infected tree safe to eat?
- Yes. UC IPM says the fruit is safe to eat, and APHIS says the disease poses no health threat to people or animals, though the fruit may be bitter and misshapen.[1][2]
- Can I mail home-grown citrus to family?
- Not out of a quarantined area. APHIS asks people not to mail or transport home-grown citrus fruit or plants out of one.[2]
Sources
- University of California Statewide IPM Program, “Asian Citrus Psyllid and Huanglongbing Disease (Pest Notes).” ipm.ucanr.edu/home-and-landscape/asian-citrus-psyllid-and-huanglongbing-disease/ (accessed 2026-11-11)
- USDA Animal and Plant Health Inspection Service (APHIS), “Citrus Greening and Asian Citrus Psyllid.” www.aphis.usda.gov/plant-pests-diseases/citrus-diseases/citrus-greening-and-asian-citrus-psyllid (accessed 2026-11-11)
- USDA Animal and Plant Health Inspection Service (APHIS), “Asian Citrus Psyllid and Citrus Greening Regulated Articles, 7 C.F.R. 301.76-2(a).” www.aphis.usda.gov/sites/default/files/citrus-greening-asian-citrus-psyllid-regulated-articles_2.pdf (accessed 2026-11-11)
- Texas Department of Agriculture, “Citrus Greening Quarantine.” www.texasagriculture.gov/Regulatory-Programs/Plant-Quality/Pest-and-Disease-Alerts/Citrus-Greening (accessed 2026-11-11)
- Annual Review of Entomology, via PubMed, “Biology and management of Asian citrus psyllid, vector of the huanglongbing pathogens (Grafton-Cardwell et al. 2013).” pubmed.ncbi.nlm.nih.gov/23317046/ (accessed 2026-11-11)
- iNaturalist, “Diaphorina citri taxon page (order and family).” www.inaturalist.org/taxa/199388 (accessed 2026-11-11)