Leafblotch miner larvae are pale green, slightly flattened with a retracted head, up to 4 mm long, living singly within distinct leaf mines. The tiny adult moth is seldom seen, but it ranges over much of the Eastern United States. Ectoedemia leaf injury appears as a brown, circular blotch mine (+ 1 cm diameter) just below the leaf cuticle. Mines originate from a narrow entrance mine and are filled with frass in the center (fig. 8). Heavily mined leaves drop prematurely. Injury is unsightly, but its impact on tree health usually is slight to negligible. Natural enemies control most populations. Direct controls are rarely needed.

Drab prominent larvae are light green with a broad, yellowish-white dorsal stripe (with brownish patches) and narrow indistinct lines on each side. A pair of taillike projections is borne on the last abdominal segment. Mature larvae are 30 to 42 mm long (fig. 9) and may be present from April to September. Young larvae feed close together and skeletonize the undersides of leaves. Large larvae become solitary feeders and will devour all but a leaf’s major veins. There are two to three generations per year. Parasites keep most populations in check.