Divisi
Citrus leafminer
Phyllocnistis citrella · Insect
Photo: Eiku · CC BY 4.0
Citrus leafminer is a tiny silvery moth (Phyllocnistis citrella) whose grub tunnels just under the skin of soft, new citrus leaves, leaving a winding silvery trail with a fine dark line of droppings down the middle. It attacks only tender new flush on citrus, oranges, lemons and limes, so older hardened leaves and resting trees are safe. The mining curls and stunts young growth and opens wounds that let in citrus canker, and it hurts most on young trees and nursery seedlings that need every leaf to build their frame.
Toby Hudson · CC BY-SA 3.0 
Jeffrey W. Lotz, Florida Department of Agriculture and Consumer Services, Bugwood.org · CC BY 3.0 us
Why it matters
On young citrus trees and nursery seedlings the leafminer can spoil up to 1 in 5 of the new leaves (about 20%) — twisting and stunting the very growth a young tree needs to build its frame, so it grows slowly and comes into fruit late. The grub does its damage hidden inside the leaf, in a tunnel just under the skin, where a spray that only wets the surface cannot reach it. Worse, every mine is an open wound that lets in citrus canker, a disease far harder to cure than the leafminer itself. Once a flush is heavily mined the leaves are already spoiled — so the whole game is protecting each new flush before the grubs get in.
When to act
Fresh flush present with serpentine mines appearing on new leaves; act on young trees and nursery stock when flush is actively mined.
This guidance is general, compiled from published agronomic references including FAO and CABI. Thresholds and timing shift with your crop, your variety and the season.
In much of the region a spray is simply called mushonga — medicine. But a chemical group you cannot name is one you cannot rotate, and a product you did not write down has no pre-harvest interval you can observe. Mushonga, and other farming words →
The full citrus leafminer field guide
- Identify it
- Scout for it
- Control it
14 field-guide sections in the app
The full guide to citrus leafminer — every symptom to check, how and when to walk your field looking for it, and the controls that actually work, ranked. Built into your crop plan, so you are told to look before it costs you a harvest.
Crops it affects
Frequently asked questions
How do I identify citrus leafminer?
The first thing you see is a silvery, winding line on a young leaf — as if a tiny snail had drawn a shiny, twisting trail just under the skin of the leaf. This is the grub's tunnel (a mine). Look closely and a fine dark thread runs down the middle of the trail — that is the grub's droppings (frass) packed inside the tunnel.
When should I take action against citrus leafminer?
Fresh flush present with serpentine mines appearing on new leaves; act on young trees and nursery stock when flush is actively mined.
How do I control citrus leafminer?
Prevent it — don't push out soft growth you can't protect. Go easy on nitrogen fertiliser and on heavy watering of young trees: both force flush after flush of tender leaves, and every new flush is a fresh meal for the leafminer. Aim to make young trees flush all at once rather than a little at a time, so the tender window stays short and easy to guard.
Which crops does citrus leafminer affect?
Among the crops covered here: Lemon, Lime.
Catch it before it costs you a harvest
Divisi builds scouting into your crop plan — it tells you when to walk your field, what to look for at that stage, and what to do when you find it. Free for farmers, works offline.
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