Idaho is home to over 189 documented moth species, from the massive wingspan of silk moths to the lightning-fast flight of sphinx moths.
While you might think moths are just drab cousins of butterflies, you’ll find that Idaho’s moths display spectacular eyespots, vibrant colors, and fascinating behaviors that rival any butterfly.
Whether you’re spotting them at your porch light or discovering them in Idaho’s forests, wetlands, and gardens, these 25 species represent the diversity of moths you’ll encounter across the Gem State.
1. Luna Moth
The luna moth (Actias luna) ranks among Idaho’s most breathtaking nocturnal visitors. You’ll recognize these pale green beauties by their long, sweeping tail streamers and distinctive eyespots on each wing. These silk moths can reach wingspans up to 4.5 inches, making them hard to miss when they flutter around outdoor lights in late spring and early summer.
Adult luna moths live only about one week and don’t eat at all during this time. They emerge from their cocoons with one single purpose: to mate and lay eggs. The caterpillars feed on leaves from walnut, hickory, sweetgum, and persimmon trees. If you find a lime-green caterpillar with yellow stripes and small orange spots, you’ve likely spotted a luna moth larva preparing for its remarkable transformation.
2. Polyphemus Moth
The Polyphemus moth (Antheraea polyphemus) catches your attention immediately with large eyespots that resemble the face of a great horned owl. This clever pattern serves as a defense mechanism, startling and confusing predators when the moth suddenly reveals its hindwings. You’ll find these tan-colored giants in Idaho’s forests, orchards, wetlands, and even urban areas throughout the state.
Like luna moths, adult Polyphemus moths have extremely short lifespans of only about four days. They don’t have functional mouthparts and survive solely on energy stored from their caterpillar stage. Males use their large, feathery antennae to detect female pheromones from miles away. The caterpillars are bright green and feed on oak, willow, maple, and birch leaves before pupating in silk cocoons wrapped in leaves.
3. Cecropia Moth
North America’s largest native moth, the cecropia moth (Hyalophora cecropia), boasts wingspans reaching up to six inches. You’ll identify these spectacular insects by their reddish-brown wings with white, red, and tan bands, plus crescent-shaped white spots near the wing tips. Their bodies are covered in dense, rust-colored fur that helps insulate them during cool Idaho nights.
Cecropia moths emerge in late spring and early summer, living as adults for only one to two weeks. During this brief period, they focus entirely on reproduction. The caterpillars are equally impressive, growing up to 4.5 inches long with colorful tubercles ranging from yellow to blue along their bodies. These larvae feed on maple, cherry, birch, and apple trees, occasionally becoming numerous enough to cause noticeable defoliation.
4. Io Moth
The io moth (Automeris io) displays one of nature’s most effective defense strategies. When threatened, these moths flash large eyespots on their yellow hindwings that look remarkably like the eyes of a much larger animal. Males feature bright yellow wings while females sport reddish-brown to purplish-brown forewings, creating distinct sexual dimorphism.
You’ll typically spot io moths from May through August across Idaho. The caterpillars are unmistakable with their bright green bodies covered in venomous spines that deliver a painful sting if touched. These defensive spines protect the larvae as they feed on willow, mesquite, hackberry, and various other deciduous trees. Despite their potent defense, io moth populations face predation from birds, wasps, and other insects.
5. Imperial Moth
The imperial moth (Eacles imperialis) ranks among Idaho’s most variable silk moths in coloration. You might encounter individuals ranging from bright yellow with sparse spotting to deep purplish-brown with heavy markings. Males typically display more yellow coloring and are smaller than females, with wingspans measuring 3 to 7 inches depending on gender.
These moths prefer pine forests and mixed woodlands throughout Idaho. The large, sparsely-haired caterpillars can be orange, green, or dark brown with yellow spiracles along their sides. They feed on pine, oak, maple, sassafras, and sweetgum. Imperial moths complete one generation per year, with adults emerging in summer months. Like other silk moths, adults don’t feed and live only long enough to reproduce.
6. White-Lined Sphinx Moth
The white-lined sphinx moth (Hyles lineata) often gets mistaken for a hummingbird as it hovers at flowers, rapidly beating its wings up to 85 beats per second. You’ll recognize this species by its brown forewings with buff-colored stripes and pink hindwings with black borders. These day-flying moths feed on nectar from petunias, phlox, honeysuckle, and evening primroses using their long proboscis.
In Idaho, you might witness explosive population outbreaks when groups of caterpillars migrate together across roads and fields. The caterpillars feature a distinctive horn on their rear end and come in various color forms from yellow-green to black. They feed on evening primrose, apple, elm, grape, and tomato plants. After eating enough, they burrow underground to pupate, spending winter in the soil before emerging as adult moths in spring.
7. Hummingbird Clearwing Moth
The hummingbird clearwing moth (Hemaris thysbe) mimics hummingbirds so convincingly that you might do a double-take when you spot one in your garden. These day-flying moths have transparent wings bordered in reddish-brown, with olive-green to golden-brown bodies. They dart from flower to flower, hovering precisely while feeding on nectar.
You’ll find these moths active during daylight hours from spring through early autumn across Idaho. They prefer honeysuckle, bee balm, phlox, and snowberry flowers. The caterpillars are pale green with yellow and black spots along their sides and feed primarily on honeysuckle and snowberry plants. Unlike many sphinx moth caterpillars, hummingbird clearwing larvae have a blue-tipped horn rather than the typical black horn.
8. Snowberry Clearwing Moth
Often confused with its close relative the hummingbird clearwing, the snowberry clearwing moth (Hemaris diffinis) shares the same transparent-winged appearance and hummingbird-like flight pattern. You can distinguish this species by its black legs and the black band across the abdomen, whereas hummingbird clearwings have yellowish legs.
These moths frequent Idaho gardens and woodland edges during daylight hours, visiting flowers like honeysuckle, lilac, and verbena. The caterpillars are bright green with yellow and black markings and typically feed on snowberry and honeysuckle plants. Both clearwing moth species fill important pollination roles in Idaho ecosystems, visiting flowers that might be neglected by other pollinators during midday hours.
9. Achemon Sphinx Moth
The achemon sphinx moth (Eumorpha achemon) displays beautiful pink and brown coloring on its wings and body. You’ll notice this species lacks the typical sphinx moth characteristic of hovering at flowers; instead, it lands to feed. The forewings show intricate patterns of pink, brown, and gray, while the body features bright pink patches.
This species has adapted well to Idaho’s varied landscapes, from gardens to vineyards. The unusual caterpillars go through dramatic color changes as they mature, starting brown with eyespots, then green, and finally reddish-brown before pupation. They feed on grape vines and Virginia creeper, occasionally becoming numerous enough in vineyards to be considered minor pests. The caterpillars lose their horn as they mature, leaving only a small bump where it once existed.
10. Blinded Sphinx Moth
The blinded sphinx moth (Paonias excaecata) gets its curious name from the small, incomplete eyespots on its hindwings. You’ll identify this species by its pinkish-brown or grayish-brown forewings with darker bands and subtle pink tones. The eyespots lack the prominent white centers found in related species, giving them a “blind” appearance.
These moths inhabit Idaho’s deciduous woodlands and can be found near willow, poplar, birch, and cherry trees. The caterpillars are bright green with seven white, yellow-edged diagonal stripes along their sides and a reddish horn. They feed on the foliage of their host trees throughout summer. Adult moths fly from May through August and are attracted to lights at night.
11. Twin-Spotted Sphinx Moth
The twin-spotted sphinx moth (Smerinthus jamaicensis) earns its name from pairs of blue and black eyespots on its pink and brown hindwings. You’ll find these moderately-sized sphinx moths resting on tree trunks during the day, where their mottled gray and brown forewings provide excellent camouflage against bark.
This species inhabits Idaho’s wooded areas and urban neighborhoods with abundant host plants. The caterpillars are bright green with a blue or purple horn and feed on apple, ash, birch, and willow trees. When disturbed, the larvae can make a clicking sound by moving their mandibles rapidly. Adults emerge in late spring through summer and are strongly attracted to artificial lights.
12. Galium Sphinx Moth
The galium sphinx moth (Hyles gallii) showcases olive and tan forewings with white lines and rose-pink hindwings with black markings. You might spot this species in Idaho’s gardens and meadows where bedstraw and related plants grow. These moths fly during dusk and throughout the night, visiting flowers for nectar.
The caterpillars vary in color from green to reddish-brown or black, typically with a series of pale spots along their sides. They feed on bedstraw, fireweed, and evening primrose. This species can produce two generations per year in warmer areas of Idaho. The moths migrate northward each spring and don’t survive Idaho’s cold winters, requiring new populations to arrive each year.
13. Western Poplar Sphinx Moth
The western poplar sphinx moth (Pachysphinx occidentalis) represents one of Idaho’s larger sphinx moths, with wingspans reaching up to 4.5 inches. You’ll recognize this species by its gray and brown mottled pattern that provides excellent camouflage when resting on poplar and willow bark. The hindwings display bands of soft gray and white.
These moths emerge in June and July across Idaho’s river valleys and foothill areas where cottonwoods and poplars grow. The large, thick-bodied caterpillars are pale green with white, diagonal markings and a pink or orange horn. They feed exclusively on poplar and willow leaves, sometimes becoming locally abundant. The larvae pupate in soil chambers where they spend the winter before emerging as adults the following summer.
14. Pandora Sphinx Moth
The pandora sphinx moth (Eumorpha pandorus) displays exquisite olive-green and pink coloration on its wings and body. You’ll identify this elegant species by its smooth, streamlined appearance and the pink patches on its olive-green forewings. The hindwings are primarily pink with green margins, creating a sophisticated color combination.
This species prefers areas with grape vines and Virginia creeper throughout Idaho. The caterpillars go through remarkable transformations during their development, changing from light green juveniles to large, reddish-brown mature larvae with prominent eyespots near the head. Unlike most sphinx moth caterpillars, older pandora sphinx larvae completely lose their horn, leaving only a smooth, polished button where it once grew.
15. Vine Sphinx Moth
The vine sphinx moth (Eumorpha vitis) closely resembles the pandora sphinx but typically shows more tan and brown tones mixed with pink on its wings. You’ll find this species wherever wild and cultivated grapes grow across Idaho. These moths have streamlined bodies and narrow wings adapted for swift, sustained flight.
The caterpillars are polymorphic, appearing in various color forms including green, brown, and reddish variations. All forms feature the characteristic sphinx moth horn and diagonal stripes along their sides. They feed primarily on grape leaves and can occasionally reach high enough numbers to cause noticeable defoliation in vineyards. The moths overwinter as pupae in underground chambers and emerge in late spring.
16. Tomato Hornworm Moth
The tomato hornworm moth (Manduca quinquemaculata), also called the five-spotted hawkmoth, is known more for its caterpillar than its adult form. You’ll recognize the adult moths by their gray forewings with zigzag black and white lines and gray hindwings with dark bands. Five or six orange-yellow spots mark each side of the abdomen.
These moths emerge at dusk to feed on nectar from deep-throated flowers like petunias, moonflowers, and jimsonweed. The infamous caterpillars are bright green with white V-shaped markings and a black horn, growing up to four inches long. They can devastate tomato, pepper, eggplant, and potato plants in Idaho gardens, stripping entire plants of foliage in just days. Gardeners often find them by following the trail of droppings beneath affected plants.
17. Tobacco Hornworm Moth
The tobacco hornworm moth (Manduca sexta), or Carolina sphinx moth, looks nearly identical to the tomato hornworm moth but features six pairs of yellow-orange spots on its abdomen instead of five. You’ll struggle to tell these species apart without counting the abdominal spots carefully. Both moths have similar gray coloring with intricate patterns on their wings.
The caterpillars differ more noticeably, with tobacco hornworm larvae displaying diagonal white lines with black borders rather than V-shaped markings. They also have a red horn instead of black. These caterpillars feed on tobacco, tomato, pepper, and other nightshade family plants. Despite their pest status, both hornworm species serve as important pollinators of evening-blooming flowers across Idaho.
18. Cabbage Looper Moth
The cabbage looper moth (Trichoplusia ni) presents as a mottled brown and gray moth with a distinctive silver figure-eight marking on each forewing. You’ll find these small to medium-sized moths throughout Idaho’s agricultural areas and home gardens. They fly erratically and are active at night, often attracted to lights.
The pale green caterpillars lack some of the legs other caterpillars have, causing them to move in a characteristic looping motion that gives them their name. They’re serious pests of cabbage, broccoli, cauliflower, kale, and other cole crops. The moths can produce multiple generations per year in Idaho’s warmer regions. Organic gardeners often use row covers or Bacillus thuringiensis to control these persistent pests.
19. Yellow Underwing Moth
The yellow underwing moth (Noctua pronuba) hides bright yellow hindwings beneath brown forewings. You won’t see the vivid yellow coloring until the moth takes flight or feels threatened and exposes its hindwings in a defensive display. The forewings feature intricate patterns of brown, tan, and gray that provide excellent camouflage when the moth rests.
Originally from Europe, this species has spread across North America and established populations throughout Idaho. The brown caterpillars, called cutworms, live in soil during the day and emerge at night to feed on a wide variety of plants. They cut through stems at ground level, causing seedlings and young plants to topple over. Adults fly from June through October and are strongly attracted to lights.
20. Fall Armyworm Moth
The fall armyworm moth (Spodoptera frugiperda) displays mottled gray and brown forewings with subtle white markings. You’ll recognize males by the triangular white spot near the wing tip and pale center area on each forewing. Females have more uniform coloring without distinctive markings.
These moths are significant agricultural pests across Idaho, with caterpillars feeding on corn, sorghum, cotton, soybeans, and various grasses. The larvae vary in color from green to brown or black and feature distinctive inverted Y-shaped markings on their heads. Fall armyworms earned their common name from their habit of moving across fields in large numbers, resembling an army on the march. They can complete their entire life cycle in about 30 days during warm weather, allowing for multiple generations.
21. Giant Leopard Moth
The giant leopard moth (Hypercompe scribonia) stands out dramatically with its white wings covered in hollow black and blue spots. You’ll easily identify this striking species by its bold pattern that resembles a leopard’s rosettes. The abdomen displays bright metallic blue coloring with orange bands, visible when the moth is at rest with wings folded.
This species inhabits wooded areas, fields, and gardens throughout Idaho. The caterpillars, called woolly bears, are covered in black bristles with red bands between body segments. They feed on a wide variety of plants including cherry, maple, willow, and various garden plants. When threatened, the caterpillars curl into a tight ball, and the bristles can cause skin irritation in sensitive individuals.
22. Virgin Tiger Moth
The virgin tiger moth (Grammia virgo) displays bold black and white patterns on its forewings and vibrant pink or red hindwings. You’ll notice considerable variation in this species, with some individuals showing more white and others more black on their wings. The thorax features white lines on a black background, and the abdomen shows red and black segments.
These moths inhabit open areas, meadows, and forest edges across Idaho. The caterpillars are classic woolly bears with dense tufts of black, white, and orange bristles. They feed on various low-growing plants including plantain, dandelion, and clover. Adult moths fly during summer months and are occasionally attracted to lights. When disturbed, they can emit defensive chemicals that taste unpleasant to predators.
23. Banded Tussock Moth
The banded tussock moth (Halysidota tessellaris) presents as a pale yellow to cream-colored moth with translucent wings and darker bands. You’ll identify this species by the wavy, broken lines that cross the wings and the fuzzy yellow or cream-colored body. These moths have a delicate, almost ghostly appearance.
The caterpillars are far more conspicuous than the adults, featuring black bodies with four cream-colored tufts of hair along the back and longer black and white hair tufts at both ends. They feed on a wide range of trees and shrubs including oak, birch, willow, and various fruit trees. While the hairs aren’t venomous, they can cause skin irritation. The species completes one or two generations per year depending on location within Idaho.
24. Salt Marsh Moth
The salt marsh moth (Estigmene acrea) displays white to pale yellow wings with occasional small black spots. You’ll notice the bright yellow-orange abdomen with black spots running down the center and sides. Males typically have more spotted forewings than females, which often have pure white wings.
Despite its name suggesting coastal habitats, this species thrives throughout Idaho’s agricultural areas and gardens. The caterpillars, sometimes called salt marsh caterpillars or acrea moths, are covered in dense tufts of brown, black, orange, and white hairs. They feed on an extremely wide range of plants, from vegetables and field crops to ornamentals and weeds. Adults emerge throughout the summer months and are frequently attracted to lights.
25. Isabella Tiger Moth
The isabella tiger moth (Pyrrharctia isabella) is the adult form of the famous woolly bear caterpillar used in folklore to predict winter severity. You’ll recognize the adults by their yellow-orange to yellowish-brown wings with sparse black spotting and bright orange legs. Females typically have more brightly colored hindwings than males.
These moths have a fascinating survival strategy that allows them to thrive in Idaho’s cold climate. The caterpillars survive winter by producing a cryoprotectant in their tissues that prevents ice damage, essentially freezing solid and thawing out in spring. They feed on a wide variety of low-growing plants including grasses, dandelions, and plantain. The fuzzy orange and black caterpillars are frequently seen crossing roads and sidewalks in fall as they search for protected overwintering sites.
