Leafminers 🐛
Various fly, moth, beetle, and sawfly larvae
At a glance
- Looks like: Pale winding tunnels or blotches inside the leaf tissue
- Tell-tale sign: Damage is inside the leaf, not chewed from the edge
- Severity: Usually minor on established plants; more important on seedlings or new citrus flush
How to identify
Leafminers are larvae feeding between the upper and lower leaf surfaces, leaving pale serpentine trails, blotches, or papery windows. On citrus, mines often curl and distort tender new leaves. The larva may be visible as a tiny pale speck at the end of an active mine.
Damage
Most damage is cosmetic on mature plants. Heavy mining can reduce photosynthesis on seedlings or tender new growth, and citrus leafminer can make young citrus flush look badly twisted.
Treatment (least-toxic first)
Following Integrated Pest Management:
- Remove badly mined leaves on small plants if it is easy, but do not strip a plant bare.
- Avoid pushing constant tender new growth with heavy nitrogen; leafminers target soft flush.
- Protect natural enemies outdoors; many leafminers are heavily parasitized.
- Do not chase old mines with sprays — the larva may already be gone.
Prevention
For citrus, avoid frequent pruning that triggers repeated new flush. Monitor seedlings and young plants more closely than established shrubs or trees.
Affects (in this guide)
Citrus, vegetables, many herbaceous plants, and occasional ornamentals