Extension > Garden > Diagnose a problem > What insect is this? > Garden Pests > Flies, moths, wasps,and other insects with obvious wings - Under 1/4 inch long > Spinach leaf miner

Spinach leafminer

Pegomya hyoscyami

Whitney Cranshaw, Colorado State University, Bugwood.org

Description: 1/4 inch long. Gray to black slender body. Has dark stripes on the thorax. Has clear wings. Note: Similar looking flies may also be present. Have flies identified if there is concern that they may be pests.

Where/When: Adults lays eggs on the leaves of spinach, beets, chard, lambsquarter, and other plants. Larvae feed between the two leaf surfaces, creating mines inside the leaves. Active April and May. A second generation can be seen in June.

Significance: Their feeding has little impact on plant growth so is not considered a pest to beets. However, they can be quite destructive to vegetables grown for edible greens, like spinach.

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