Asian Citrus Psyllid: How to Spot It and Protect Your Citrus
This tiny bug is killing citrus trees, and it's already in Southern Arizona. The Asian citrus psyllid is barely 1/8 inch long, but it spreads citrus greening, a disease with no cure. Here's how to spot it on your trees in 5 minutes, and exactly what to do if you find it.
Watch: what Asian citrus psyllids look like on a real tree
WHY THIS MATTERS
The bug isn't the killer. The disease it carries is.
The Asian citrus psyllid feeds on new citrus leaves. On its own it does little damage. The danger is that it spreads citrus greening (also called HLB, or Huanglongbing), a bacterial disease with no cure. An infected tree slowly declines, its fruit turns bitter, and it eventually has to be removed.
It's already in Arizona. Citrus greening was confirmed in Nogales in January 2025, and the area is under state and federal quarantine. The psyllid itself has been found throughout Southern Arizona's citrus-growing areas, including the Tucson region. |
Florida has spent 20 years fighting this disease. Here, we still have time to keep it from spreading, and that starts in backyards like yours.
What citrus greening looks like
 Blotchy, lopsided yellowing. The pattern doesn't match from one side of the leaf to the other. Fertilizer and water won't fix it. |  Uneven ripening. Fruit stays green, especially at the bottom, and is often small, lopsided and bitter. |
HOW TO SPOT IT
Check your new growth. That's where they hide.
Psyllids lay their eggs only on soft, new leaves (the "flush"). Every time your tree pushes new growth, look closely at the tips and the undersides of the young leaves.
 | 1 White, waxy curlsYoung psyllids (nymphs) are tiny and yellow-orange. They push out curly white wax strings, which are the easiest sign to see from a few feet away. |
 | 2 Tiny brown adultsAdults are about 1/8 inch long and mottled brown. They feed with their tail end tipped up at an angle to the leaf, like a thorn sticking out. |
 | 3 Waxy dripsLook for clear, waxy droplets hanging from new shoots, and for new leaves that curl or twist as they open. |
WHAT TO DO
Your 4-step action plan
1. Inspect every week during new growth
Citrus pushes new growth in spring, after monsoon rains, and in the fall. Spend 5 minutes a week checking new tips and leaf undersides.
2. Hang a yellow sticky trap
Catches adults so you know the moment they arrive. Check it weekly.
Monterey Asian Citrus Psyllid Trap & Lure Our pick for early warning |
3. Found them? Spray the new growth
Pick one of these organic options:
Safer Brand Neem Oil Oil spray: smothers nymphs and adults on contact |
Bonide Captain Jack's Deadbug Brew Spinosad spray: a good option when it's too hot for oil |
Soak the new growth, undersides too. These sprays only kill what they touch.
Repeat every 7–10 days until new leaves harden off.
Never spray during bloom (protect the bees), and skip oil sprays above 90°F.
Always follow the product label. In the Nogales quarantine zone, the state sprays for free, so don't spray yourself.
4. Suspect greening? Don't move anything.
Don't cut or remove the tree, and don't move leaves, branches or fruit off your property. Call the Arizona Department of Agriculture:
Tucson office: Pima, Cochise, Santa Cruz, Graham, Greenlee | Phoenix office: Maricopa, Pinal, Yavapai and northern counties | Yuma office: Yuma, La Paz, Mohave |
BEYOND PSYLLIDS
The best everyday protection: water your citrus right
There's no cure for citrus greening, and watering won't stop psyllids. But in our work across Tucson, the most common reason we see citrus trees decline isn't a pest at all. It's watering. Shallow or uneven watering stresses trees, and a stressed tree struggles with heat, pests and disease.
A tree that's watered deeply at the root zone, in healthy soil, puts out stronger growth and holds up better through Tucson summers.
 |  |
ThriveRing Tree Irrigation Kit Our kit for deep, even watering right at the root zone |
Want the full picture? Read The Most Common Fruit Tree Problems (and how to solve them), our guide to the watering, planting and soil mistakes we see most.
Prefer to watch? See our watering and soil care videos on YouTube.
PRINT THIS. TAPE IT BY THE BACK DOOR.
5-Minute Weekly Tree Check
☐ Is my tree pushing soft new leaves right now? ☐ Any curly white wax strings on new shoots? ☐ Any tiny brown bugs sitting tail-up on young leaves? ☐ Any waxy drips or twisted new leaves? ☐ Anything new on my yellow sticky trap? ☐ Any blotchy, lopsided yellow leaves or green-bottomed fruit? |
Common questions
What is the white waxy stuff on my lemon or orange tree?
Curly white wax strings on new citrus growth are a telltale sign of Asian citrus psyllid nymphs. Check the tips and undersides of young leaves for tiny yellow-orange nymphs and small brown adults.
Is citrus greening in Tucson?
Citrus greening (HLB) was first confirmed in Arizona in Nogales in January 2025, and that area is under quarantine. The Asian citrus psyllid, which spreads the disease, has been found throughout Southern Arizona's citrus-growing areas, including the Tucson region.
Can a tree with citrus greening be saved?
No. There is no cure for citrus greening. Infected trees decline over time and are removed. If you suspect greening, don't cut or move the tree yourself; call the Arizona Department of Agriculture.
When should I check my citrus for psyllids?
Check weekly whenever your tree is pushing soft new growth, which in Southern Arizona is usually spring, after the monsoon and in fall.
Not sure what's on your tree?In the Tucson area? We'll come to you. Book a 1-hour on-site visit and we'll check your citrus and fruit trees, irrigation and landscape, find what's attacking your trees, and give you a clear plan to fix it. |
Affiliate disclosure: As an Amazon Associate, Thrive and Grow Gardens earns a small commission from qualifying purchases through the Amazon links in this article, at no extra cost to you. It helps support our small, local business.
Sources: University of Arizona Cooperative Extension, Arizona Homeowner Guide to Citrus Greening Disease (AZ2132); UC Agriculture & Natural Resources, Asian citrus psyllid homeowner management; USDA APHIS citrus greening quarantine notice (Feb 2026). This article is general education. Always read and follow pesticide labels.
Comments