Noctuid Moths

More than 2,500 species in North America north of Mexico

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image of a Dagger Moth
There are more than 70 species of dagger moths (Acronicta spp.) in North America north of Mexico. Most are gray or tan, with black dagger-shaped dashes on the forewings. These noctuids are difficult to tell apart.
Donna Brunet
Other Common Name
Owlet Moths, Miller Moths, Cutworms, Armyworms, Dagger Moths, Dart Moths, Bird-Dropping Moths
Family

Noctuidae (owlet moths)

Description

Adult noctuid moths may be small to large, generally have a heavy body for their size, and hold their wings tentlike over their bodies. Most noctuids are camouflaged with lines and spots to resemble tree bark or bird droppings, but they can be subtly gorgeous with ornate patterns on their gray or tan wings. Some noctuids are colorful; usually, bright reds, oranges, or yellows with black markings warn predators they are toxic or unpalatable.

This is a large family that includes dagger, owlet, and bird-dropping moths, and more. The group also includes armyworms, cutworms, corn earworms, the iris borer, and other pests.

Caterpillars in the noctuid family are so varied they cannot be described simply. The familiar cutworms and armyworms are pudgy, waxy looking, and hairless, while the caterpillars of dagger moths are hairy with tuftlike "pencils" of longer hairs. Some noctuid caterpillars are loopers, which "walk" by arching their backs. (Note that caterpillars in the geometrid family are also called loopers, because they walk the same way.)

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image of an Armyworm moth
Armyworm Moth
Armyworms in genus Spodoptera eat a very wide variety of nonwoody plants. The tan, camouflaged adults resemble many of their relatives in the noctuid family.

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image of a Common Spragueia
Common Spragueia
The common spragueia is a noctuid moth with distinctive orange, yellow, and black markings. Its caterpillars are loopers that feed on bindweeds and ragweeds.

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Photo of a corn earworm moth resting on a brick wall
Corn Earworm Moth
The corn earworm moth (Helicoverpa zea) is a widespread and variable noctuid species. Larvae eat a wide range of crop plants.

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Photo of a bilobed looper moth resting on concrete, side view
Bilobed Looper Moth
The bilobed looper (Megalographa biloba) has a B-shaped silvery spot on each forewing. Caterpillars of this noctuid moth eat a wide range of plants.

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Photo of an Eight-Spotted Forester on a flower
Eight-Spotted Forester
The eight-spotted forester is a spiffy, butterfly-like moth. It is a fast, darting flyer and dazzles the eye when it flutters around flowers.

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Forage looper moth perched on a brick wall, viewed from side
Forage Looper Moth
The forage looper moth is one of the most abundant and common moth species in Missouri. The larvae eat clover and alfalfa.

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Yellow underwing moth resting on a fabric surface
Yellow Underwing
The yellow underwing (Noctua pronuba) was introduced to North America from Eurasia in 1979. Its larva, the winter cutworm, eats a wide range plants, including crops and grasses.

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Photo of a Celery Looper taking nectar from a flower
Celery Looper
Adult celery looper moths look like dead leaves. A closer look reveals subtly gorgeous, ornate patterns on the wings.

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Photo of a beautiful wood-nymph
Beautiful Wood-Nymph
The beautiful wood-nymph rests with its white and brown forewings folded like a roof over its yellow hindwings. At rest, this moth resembles a bird dropping.

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Image of a Black-Bordered Lemon Moth
Black-bordered Lemon Moth
The black-bordered lemon moth moth has lustrous yellow forewings with a black edge. It is one of the many species of noctuid, or owlet moths.

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Yellow-haired dagger caterpillar on a stem
Yellow-Haired Dagger Caterpillar
The caterpillars of dagger moths (genus Acronicta) are usually hairy, with odd arrangements of clumps and tufts of hairs.
Habitat and conservation

Most noctuid moths are nocturnal, flying at night and resting by day. They avoid visual predators by blending in with the tree bark they rest on, or by resembling bird poop. Most are attracted to lights at night, and moth collectors also dab a sugar solution onto tree trunks to lure them in.

Foods

The preferred host plant of noctuid caterpillars varies depending on the species. Most eat at night. Some species have limited food plants, while others may eat a wide variety. They usually feed externally on plants, but some are borers or create leaf shelters. Several noctuids are serious crop or garden pests. Cutworms, for example, chew off young plants right at the base, then drag the severed plant top underground. Adults usually feed on nectar from flowers or drink sap leaking from an injured tree.

Distribution in Missouri

Statewide.

Status

This very large family used to be much larger, because it used to also include the tiger and lichen moths, tussock moths, underwings, and others. Scientists are still refining their organization of these large and confusing groups. The relatively new tool of DNA testing has helped scientists gauge how closely related different animal groups are, and there may be more changes in the coming years.

Life cycle

Noctuids have the same general life cycle of other moths, progressing from egg to caterpillar to pupa to winged adult. Some species have only one or a few broods a year, while others may have many. Different species overwinter at different times in their life cycle. Many spend the winter as pupae, either underground or in unsubstantial cocoons above ground in leaf litter. Others survive winter as caterpillars. Still others overwinter as eggs or even adults. Some cutworm species grow to a mature size in spring or early summer, then stop feeding and rest until late summer, and then pupate.

Human connections

One reason why noctuids are called "owlet" moths is that their eyes reflect a light shone on them at night.

The caterpillars of several noctuid species are agricultural pests. For this reason, many of them are very well studied.

Ecosystem connections

Noctuid moths have an interesting adaptation to defend against bats, their chief predators. A flying bat uses its radar-like echolocation to find and target individual moths. But a noctuid moth usually begins flying erratically — diving or cartwheeling — right before a bat swoops to get it. It turns out noctuid moths can hear the pulses of ultrasonic sound made by bats, sense their archenemy’s position and movements, and reflexively make appropriate evasive maneuvers.