The adult female Echinothrips americanus is about 1.6 mm long and the male about 1.3 mm long. The general body color is dark brown with red between the abdominal segments.
Forewings are pale gray at base, middle, and tip with light brown in between.
Laid in plant tissue, elongate and clear to white. Immediately after hatch the larvae are clear but they change to white and then become light or pale yellow after feeding. The second-stage larvae become cream colored before molting to prepupae. Both are found on leaf tissue and move only when disturbed. Prepupa is white with short wing pads and antennae extend forward.