Any butterfly in the subfamily Theclinae (family Lycaenidae), sometimes known as gossamer-winged butterflies.
Adults are delicate and have a 0.75–1.5-in. (18–38-mm) wingspan. Rapid fliers, hairstreaks usually have iridescent wings and are typically brown or gray with delicate stripes on the bottoms of the wings. Larvae are short, broad, and sluglike. Some species eat plants, many are cannibals, and still others secrete honeydew, a sweet by-product of digestion that attracts ants . Found in open areas on every continent, hairstreaks are most abundant in the New World tropics.