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How to identify it
- The hindwings are bright orange in males and usually more yellowish and less bright in females. The forewings are gray, tan or brown with variable markings, usually straight lines and often a single dark spot.[1]
- The wingspan is 1/2 to 1 inch. Like other geometrid moths it has a slender body and rests with its wings held flat.[1]
- The caterpillar is a slender inchworm under 2 cm (about 3/4 inch) long, green or brown, with many fine lengthwise stripes. The stripes along the back tend to be tawny, while those lower on the sides are whiter and often broken into spots. MDC describes the green caterpillars as having a brownish-orange head.[2][1]
Look-alikes
| Look-alike | How to tell them apart |
|---|---|
| Other geometrid moths | Most geometrids have markings that run smoothly from the forewings onto the hindwings. The orange wing stands out because its orange hindwings contrast with its bark-colored forewings, and it is the only species in its genus in North America.[1] |
Where it lives
The USDA Forest Service gives its range as extreme southern Ontario to New Jersey and Florida, west to Illinois and Texas, and notes that it is particularly common in the Midwest and South. Although honey locust has been planted throughout the East, the moth has not yet followed it into many states where the tree is now a common shade tree. In Missouri it is found statewide.[2][1]
Biology and life cycle
Honey locust is the host. The USDA Forest Service reports that the caterpillars refuse black locust, while the Missouri Department of Conservation says they may possibly feed on other woody legumes.[2][1]
Adults are active both day and night. In Missouri they fly from early April into September, and there are several broods a year; Maryland and Ohio have at least three generations, with full-grown caterpillars from late June through November.[1][2]
By day the moths are easily flushed from foliage and often fly some distance before settling again.[1]
It spends the winter as a pupa.[2]
Damage and signs
- The caterpillars eat honey locust leaves. The Missouri Department of Conservation describes them as a natural pruning mechanism on the tree, and every stage of the insect is food for predators.[1]
Health risk
Neither the Missouri Department of Conservation nor the USDA Forest Service mentions any bite, sting or other risk to people.[1][2]
Control
Prevention
Neither source recommends any control; the Missouri Department of Conservation calls the orange wing an abundant resident whose caterpillars act as natural pruners on honey locust.[1][2]
Common questions
- What is the little orange moth that flies up from my honey locust?
- Most likely an orange wing. It is active by day and night, is easily flushed in the daytime, and shows its bright orange hindwings even in flight.[1][2]
- Will orange wing caterpillars hurt my honey locust?
- They feed on its leaves, but neither the Missouri Department of Conservation nor the USDA Forest Service treats them as a pest; MDC calls them a natural pruning mechanism.[1][2]
- Does the orange wing feed on black locust?
- No. The USDA Forest Service reports that the caterpillars refuse black locust; honey locust is the host.[2]
Sources
- Missouri Department of Conservation, “Orange Wing (Field Guide).” mdc.mo.gov/discover-nature/field-guide/orange-wing (accessed 2026-11-09)
- USDA Forest Service, Forest Health Technology Enterprise Team, “Geometroid Caterpillars of Northeastern and Appalachian Forests, FHTET-2001-10 (D. L. Wagner, D. C. Ferguson, T. L. McCabe and R. C. Reardon, September 2001; scanned copy).” archive.org/details/geometroidcaterp00wagn (accessed 2026-11-09)
- iNaturalist, “Mellilla xanthometata taxon page (order and family).” www.inaturalist.org/taxa/118501 (accessed 2026-11-09)