What's Eating My Citrus Tree?
Citrus pests write their signatures on the leaves: squiggles, bumps, stippling, and one caterpillar disguised as something a bird already ate. Here's the handwriting analysis.
Citrus leafminer
The signs: Silvery, winding squiggle-trails inside the surface of new leaves, which then curl and distort.
What it looks like: A tiny moth's larva mining only the fresh flush — older leaves are safe.
What to do: Tolerate it on mature trees (damage is cosmetic), avoid heavy fertilizing that pushes constant tender flush, and let the wasps that parasitize miners work.
Scale insects
The signs: Bumps stuck fast to twigs and leaf undersides — brown domes or white cottony tufts — with sticky honeydew and sooty mold below.
What it looks like: Immobile armored or soft scales; the crawl stage is nearly invisible.
What to do: Horticultural oil sprays timed to crawler emergence smother them; ladybird beetles handle light loads. Control the ants that farm them.
Aphids
The signs: Curled sticky new growth, sooty mold, ant highways.
What it looks like: Colonies on tender flush, often black citrus aphids.
What to do: Blast and soap the flush; band trunks against ants so beneficials can work.
Orange dog caterpillar
The signs: Chunks eaten from young leaves; a caterpillar that looks exactly like a fresh bird dropping on the leaf.
What it looks like: Young giant swallowtail — poke it and red horns emerge with a strong scent.
What to do: On a big tree, leave them and take the spectacular butterflies; on a small potted tree, relocate them to a wild citrus relative or sacrifice a branch.
Spider mites
The signs: Pale stippled leaves with a dusty look in hot dry spells or indoors.
What it looks like: Tap-test specks; webbing at the worst.
What to do: Shower the foliage regularly; oil or soap for outbreaks.
Snails
The signs: Ragged holes in leaves and rasped young fruit rinds, slime trails on the trunk — a big deal in California and Gulf gardens.
What it looks like: Brown garden snails sheltering in the canopy skirt by day.
What to do: Skirt-prune the canopy off the ground, copper-band the trunk, and hand-collect at dusk. Ducks, where you keep them, are the classic homestead solution.
When it's not a pest at all
Yellow leaves with green veins on new growth signal iron or manganese hunger, not feeding — common in alkaline or waterlogged soils. But blotchy asymmetrical mottling with lopsided bitter fruit can be citrus greening (HLB), the industry's gravest disease: if you're in a citrus state and see it, contact your extension office — don't guess.
Or just point your phone at it
Snap a photo of the leaf, the bug, or the droppings, and Harold — the advisor built into Homestead Paradise — names what he sees, tells you friend or foe, and what he'd do next. Honest when he's unsure, and careful where it counts.
Put Harold's Eyes on it — free 14-day trial