In Montana the moths flying tonight change with the season. July nights bring the Western Tent Caterpillar Moth (Malacosoma californica), the day-flying tiger moth Gnophaela vermiculata, the introduced leafy-spurge control moth Hyles euphorbiae, the sphinxes Sphinx vashti and Smerinthus cerisyi, and the buckmoth Hemileuca eglanterina. In May the day-active Snowberry Clearwing (Hemaris diffinis) joins early tiger and tent moths, while September shifts to the spotted tiger moth Lophocampa maculata and the woolly-bear adult Pyrrharctia isabella.
What's flying right now in Montana
Montana spans prairie, foothills, and high country, so its moth list leans western and shifts with both elevation and month. For tonight's most likely flyers at your exact spot, open the live predictor - it reads open GBIF records for your location and date.
Summer (July) moths in Montana
Midsummer is the busiest stretch. Typical July flyers include:
- Western Tent Caterpillar Moth (Malacosoma californica) - the western counterpart to the eastern tent moth, common in the foothills
- Gnophaela vermiculata (Police Car Moth) - a striking black-and-white tiger moth that flies by day around meadows
- Hyles euphorbiae (Leafy Spurge Hawk Moth) - a sphinx introduced as a biocontrol for invasive leafy spurge; like other sphinxes it nectars as an adult and flies strongly
- Sphinx vashti and Smerinthus cerisyi (One-eyed Sphinx) - native hawk moths
- Hemileuca eglanterina (Sheep Moth) - a colorful day-flying buckmoth of open country
Spring (May) moths in Montana
May is cooler and dominated by early western specialists: the Western Tent Caterpillar Moth (Malacosoma californica), the sphinx Sphinx vashti, the tiger moth Arctia tigrina, the lappet moth Phyllodesma americana, and the day-active Snowberry Clearwing (Hemaris diffinis) - a bumblebee mimic that hovers at flowers like a tiny hummingbird.
Fall (September) moths in Montana
Autumn quiets down to a hardy western set: the spotted Lophocampa maculata (Spotted Tussock Moth), the owlets Enargia decolor and Autographa californica (Alfalfa Looper), the woolly-bear adult Pyrrharctia isabella, and the geometrid Aplocera plagiata. Cold high-country nights cut activity, so lower, warmer sites do better late in the year.
Local mothing tips
- Elevation matters a lot in Montana - the same calendar night looks very different in a warm river valley versus a cold mountain meadow.
- UV or mercury-vapor lights beat white LED bulbs. Moths come to short-wavelength light because it disrupts how they hold a flight angle, not because they seek it.
- Several day-flying species here, like Gnophaela vermiculata and the Snowberry Clearwing, are best found in sunny meadows, not at night lights.
- Hang a white sheet behind your light on a calm, warm, moonless night - see the good-night-for-moths guide.
- New to it? Start with mothing for beginners, and time a session during National Moth Week, July 18-26, 2026.
Browse other states from the moth index, or compare with Wyoming.
Frequently asked
What moths are in Montana right now?It depends on the month and elevation. July brings the Western Tent Caterpillar Moth, Gnophaela vermiculata, Hyles euphorbiae, and sphinxes like Sphinx vashti and Smerinthus cerisyi. May adds the Snowberry Clearwing; September shifts to Lophocampa maculata and the woolly-bear Pyrrharctia isabella. Run the live tool for tonight's local list.
What is the black-and-white day-flying moth in Montana meadows?That's likely Gnophaela vermiculata, the Police Car Moth, a bold black-and-white tiger moth that flies by day around mountain meadows in summer. It's harmless and a favorite sight for Montana mothers.
Is the Snowberry Clearwing a moth or a hummingbird?It's a moth. The Snowberry Clearwing (Hemaris diffinis) is a day-flying sphinx that hovers at flowers and looks like a small bumblebee or hummingbird. You'll see it by day in Montana from spring into summer, not at night lights.
Why does Montana have a hawk moth from Europe?Hyles euphorbiae, the Leafy Spurge Hawk Moth, was introduced to North America as a biological control for invasive leafy spurge. It's now established in parts of Montana and comes to lights in summer; like all sphinxes, the adult feeds on nectar.
When is the best time to see moths in Montana?Midsummer (July) is peak, especially in warm valleys and foothills. Activity drops on cold high-elevation nights, so choose a warm, calm, moonless night at lower elevation and use a UV light with a white sheet.
Top moth species per month from open-licensed GBIF records (CC0/CC-BY), aggregated over an approximate state bounding box. Butterflies excluded. GBIF download DOI: 10.15468/dl.3w3w76. Independent project; not affiliated with iNaturalist or Butterfly Conservation.