Spinach Leaf Miner
The spinach leaf miner (Pegomya hyoscyami) is a small grey fly in the family Anthomyiidae whose larvae feed inside the leaf tissue of spinach, beets, Swiss chard, and related plants. The damage appears as pale, papery blotches where the interior of the leaf has been hollowed out, rendering affected portions inedible. It is one of the most dependable cool-season pests in Northeast vegetable gardens.
Adult flies emerge in April and May, timing that puts them squarely on early spring plantings of spinach and chard. Females lay small clusters of white eggs on the undersides of leaves. Larvae hatch and immediately tunnel between the upper and lower leaf surfaces, feeding on soft tissue without breaking through the outer skin. A single larva can hollow out a large patch, and several feeding together can kill an entire leaf. The species completes two or more generations per season, so summer and fall plantings are also at risk. Pupae overwinter in the soil, allowing populations to build steadily in beds where host plants grow year after year.
A direct pest of leafy greens whose larvae mine and destroy internal leaf tissue, making crops inedible or unmarketable.
Pale, winding tunnels or blotchy translucent patches between the upper and lower leaf surfaces, caused by larvae feeding inside the leaf.
Remove and destroy mined leaves promptly. Cover plants with floating row cover to block egg-laying flies. Clear nearby weeds like lambsquarters and chickweed that host the pest.