Moths in Michigan

In Michigan, the moths you are most likely to find at a porch light right now depend heavily on the month. Across the open GBIF records we draw from, the state's most-recorded species shift dramatically through the season. In late spring and early summer you get the showpieces: the Luna Moth (Actias luna), Polyphemus Moth (Antheraea polyphemus), and the Blinded Sphinx (Paonias excaecata), all peaking in June alongside the day-flying Virginia Ctenucha (Ctenucha virginica), which is one of the single most-recorded moths in the whole state. Midsummer swaps in the Painted Lichen Moth (Hypoprepia fucosa), the Ailanthus Webworm Moth (Atteva punctella), and the Hummingbird Clearwing (Hemaris thysbe), a day-flying hawkmoth often mistaken for a tiny hummingbird. By August and September the lineup tilts hard toward tiger and tussock moths, including the Milkweed Tussock Moth (Euchaetes egle), Banded Tussock Moth (Halysidota tessellaris), and Hickory Tussock Moth (Lophocampa caryae). Then in October the Isabella Tiger Moth (Pyrrharctia isabella), whose larva is the famous woolly bear, spikes hard as caterpillars wander. These are the most-recorded, most-likely species, not an exhaustive checklist.

When are the big silk moths and sphinxes flying in Michigan?

June is the month to watch in Michigan if you want the charismatic giants. In the open records we use, June is when the Luna Moth (Actias luna), Polyphemus Moth (Antheraea polyphemus), and the Blinded Sphinx (Paonias excaecata) all reach their seasonal peak together. Polyphemus actually shows a smaller early blip in February too, but that reflects overwintering cocoons being found rather than adults on the wing. Cecropia (Hyalophora cecropia), North America's largest native moth, turns up in the Michigan records mainly as scattered late-winter cocoon finds rather than as a common summer light visitor, so seeing one is a genuine treat.

The hawkmoths spread out more. The Lettered Sphinx relative Deidamia inscriptum appears among the most-recorded species back in April, one of the earliest sphinx moths to fly here. Then in July the Hummingbird Clearwing (Hemaris thysbe) becomes prominent. This is a day-flying sphinx that hovers at flowers like bee balm and phlox, so you do not need a light or even darkness to find it.

What moths fly in Michigan in spring?

Michigan's moth season warms up slowly. In March and April the most-recorded species are the muted, cold-hardy ones: early geometrids like Phigalia titea and Paleacrita vernata (the spring cankerworm), the spring Orthosia hibisci, and The Infant (Archiearis infans), a small orange-and-brown day-flier that is one of the first moths on the wing while snow can still be on the ground. The woolly bear's adult, Isabella Tiger Moth (Pyrrharctia isabella), is already among the top species by March.

May brings a sharp jump. The single most-recorded May species in the state's records is the Eastern Tent Caterpillar Moth (Malacosoma americana), reflecting those familiar silken nests in cherry and apple trees. May also surges with the day-flying Virginia Ctenucha (Ctenucha virginica) and a wave of geometrids and noctuids such as Eutrapela clemataria and Crocigrapha normani.

What about midsummer, July and August?

July is peak diversity at the light. Alongside the spongy moth (Lymantria dispar), which dominates the raw counts in June and July as an invasive species, you start seeing the Painted Lichen Moth (Hypoprepia fucosa), the orange-and-black Ailanthus Webworm Moth (Atteva punctella), the Virginian Tiger Moth (Spilosoma virginica), and a long list of geometrids like Macaria pustularia and Scopula limboundata.

August is the tussock-and-tiger turn. The Milkweed Tussock Moth (Euchaetes egle) is the top-recorded August species in Michigan, fitting for a state with abundant milkweed. It flies alongside the Banded Tussock Moth (Halysidota tessellaris), White-marked Tussock Moth (Orgyia leucostigma), and the Fall Webworm (Hyphantria cunea).

What flies in Michigan in fall?

September stays tussock-heavy: the Banded Tussock Moth (Halysidota tessellaris) leads, joined by the Hickory Tussock Moth (Lophocampa caryae) and the Yellow-collared Scape Moth (Cisseps fulvicollis). October is the woolly bear's moment, and it is unmistakable in the data: the Isabella Tiger Moth (Pyrrharctia isabella) jumps to far and away the most-recorded species as caterpillars cross roads and trails looking for hibernation sites. October and November also bring cold-weather geometrids like the Bruce Spanworm (Operophtera bruceata), whose males fly in near-freezing late-autumn nights, plus a few southern migrants such as the Corn Earworm Moth (Helicoverpa zea) and Fall Armyworm (Spodoptera frugiperda) that drift north in good years. By December and January the records thin to a handful of hardy stragglers and indoor finds, with the woolly bear's adult still the most-logged species.

How the list is built

This Michigan list reflects the most-recorded moth species in open-licensed GBIF records (CC0 and CC-BY), aggregated over an approximate Michigan area, with butterflies excluded. It is a most-likely and most-recorded picture, not a complete inventory of the more than 2,000 moth species documented in the state. Rarely photographed or hard-to-identify micromoths are underrepresented, and the spongy moth's high counts partly reflect how heavily that invasive species is reported.

How do I get tonight's personalized Michigan list?

Enter your location and the tool builds a short list of the moths most likely flying near you tonight, ranked for this specific week of the year rather than the whole season. It also gives you a "good mothing night" score that blends the weather and moon, since warm, calm, humid, overcast nights near the new moon tend to bring the most moths to a light. We are a forecast and discovery tool, not a photo identifier. When you want to confirm a species from a photo, iNaturalist and the Moth Photographers Group are excellent next stops.