Pest

Leafminers

Liriomyza, Pegomya and others

Fly or moth larvae that feed between the upper and lower leaf surfaces. On vegetables the damage is mostly cosmetic except on crops grown for the leaf; heavy outbreaks on aspen can slow growth and kill branches.

Signs

• Pale winding trails or blotches that widen as the larva grows.
• Rows of small pale puncture dots where adults fed.

What favors it

Spinach leafminer on beets, chard and spinach; aspen blotch leafminer on stressed aspens.

Prevention

• Row cover on spinach, chard and beets from sowing, in beds that had no leafminers last year.
• Remove lamb's quarters and other host weeds.

Often confused with

Sources

• Leafminers in home gardensUniversity of Minnesota Extension
• Leafminers on VegetablesUniversity of Maryland Extension
• Aspen Blotch LeafminerMontana State University Extension

Why →