Leafminers

Leafminers are immature stages of flies, wasps, beetles, or moths.  The larvae make winding or large blotch mines on the foliage of broad-leaved plants.  Or they may tunnel into evergreen needles.

Plants commonly infested with leafminers include hawthorn, holly, locust, birch, elm, and vegetables, such as spinach, beets, and tomatoes.  Control by picking and destroying infested leaves.  Or thoroughly spray the foliage at times recommended for your area.