The Lesser Maple Spanworm has a wingspan of approximately 1 inch. The white forewing is crossed with variably fragmented orange to brown lines that widen towards the costa. There may be brown marks on the postmedial and terminal lines. However, in some individuals only marks along the costa are visible. The labial palps are beak-like projecting forward beyond the eyes. The caterpillar is green with contrasting narrow white, cream or yellow lines. The head is green. It grows to less than 1 inch.