Madrone Leafminer
Marmara arbutiella
2 host plants
Last updated
You will observe thin, winding serpentine trails on Pacific madrone leaves created by moth larvae tunneling within the leaf tissue. Damage appears unsightly on individual leaves but does not impact long-term tree health. Multiple leafminer species attack madrone, producing these characteristic blotch and linear mines. Damage is most evident in midsummer as miners mature.
No treatment is necessary for cosmetic leaf damage. Trees tolerate mining without health decline. If appearance is a concern, remove heavily infested leaves by hand during peak season. Madrone leafminer is a natural part of the ecosystem. Conserve parasitic wasps by avoiding insecticide applications.
Quick Reference
Adult moths are about 0.12 inch in length. Wings are held roof-like over the body and are golden bronze with white bands. The larvae vary in appearance depending on their age, as they progress through five instars. Young larvae are legless and cream-colored. Older instars have legs and are cylindrical in shape, cream-colored and about 0.125 inch in length. Mature larvae are yellow and about 0.167 inch in length. The larvae feed within the leaf tissue creating dead discolored areas on leaves. If...
Cultural Controls
- Natural predators may help control populations.
- Encourage predators such as green lacewings and spiders.