W
Species Profile

Winter Moth

Operophtera brumata

Winter flyer, spring defoliator
Henri Koskinen/Shutterstock.com

Winter Moth Distribution

Click a location to explore more animals from that region

Invasive Species
Loading map...
Winter Moth

At a Glance

Wild Species
Diet Folivore
Activity Nocturnal+
Lifespan 12 years
Status Not Evaluated
Did You Know?

Adults commonly emerge from October-January; males fly on mild nights while snow can still be on the ground.

Scientific Classification

Winter moth (Operophtera brumata) is a geometrid moth whose adults emerge in late autumn and winter. Males are winged and fly to lights; females are largely flightless and climb trees to lay eggs. Larvae (“inchworms”) feed on buds and young leaves of many deciduous trees.

Kingdom
Animalia
Phylum
Arthropoda
Class
Insecta
Order
Lepidoptera
Family
Geometridae
Genus
Operophtera
Species
Operophtera brumata

Distinguishing Features

  • Adults active in late autumn and winter
  • Females largely wingless, climb tree trunks
  • Larvae are green inchworms feeding on buds
  • Males gray-brown with wavy crosslines

Did You Know?

Adults commonly emerge from October-January; males fly on mild nights while snow can still be on the ground.

Males have a 20-30 mm wingspan; females are largely wingless and cannot fly.

Females typically lay about 100-200 eggs in bark crevices, which overwinter and hatch at budburst.

Larvae are classic "inchworms," moving by looping because they lack most middle prolegs.

It is univoltine: one generation per year, with a long pupal diapause through spring and summer.

In northeastern North America it is invasive and can cause heavy spring defoliation of deciduous trees.

Biological control in North America has used the tachinid fly Cyzenis albicans, a specialist parasitoid of winter moth larvae.

Unique Adaptations

  • Female wing reduction (flightlessness) saves energy for egg production in cold seasons when flight is inefficient.
  • Cold-season adult activity reduces competition with most other moths that fly in warmer months.
  • Overwintering eggs tolerate prolonged cold while remaining ready to hatch quickly when buds open.
  • Phenology matching to budburst lets larvae exploit nutrient-rich, soft tissues before leaves fully expand.
  • Geometrid "looping" gait suits twig- and bud-feeding, allowing precise movement on narrow branches.

Interesting Behaviors

  • Males patrol and come to lights on mild winter evenings, even when daytime temperatures stay near freezing.
  • Females crawl up trunks after emerging, then release sex pheromones to attract flying males.
  • Eggs are placed in sheltered bark fissures and under lichens, improving survival through winter exposure.
  • Larvae hatch timed to host budburst and feed on buds, flowers, and young leaves before foliage toughens.
  • When disturbed, larvae drop on silk threads and hang, reducing predation and aiding short-distance dispersal.
  • After feeding in spring, larvae enter soil to pupate and remain dormant until the next autumn-winter emergence.

Cultural Significance

In Britain and northern Europe, winter moth is a well-known phenology species recorded by naturalists; shifting flight dates are used to illustrate climate-linked seasonal change. In invaded regions, it features prominently in urban tree-management guidance.

Myths & Legends

The species name brumata comes from Latin bruma ("winter solstice"), echoing European naturalists' tradition of linking insects' names to seasonal turning points.

In parts of Japan, a moth entering the home has been treated as a visiting spirit; winter-flying moths can intensify this seasonal association.

In Irish and Scottish folk belief, night-flying moths were sometimes linked with wandering souls, making unexpected winter moth appearances feel especially portentous.

Conservation Status

NE Not Evaluated

Has not yet been evaluated against the criteria.

Population Unknown

Life Cycle

Birth 150 larvas
Lifespan 12 years

Lifespan

In the Wild
11–13 years
In Captivity
10–24 years

Reproduction

Mating System Polygyny
Social Structure Solitary
Breeding Season Late autumn-winter (November-January)
Breeding Pattern Transient
Fertilization Internal Fertilization
Birth Type Internal_fertilization

In late autumn-winter, flightless females climb trunks and emit sex pheromone; winged males locate them and mate, with males capable of multiple matings. After brief copulation, females oviposit ~100-200 eggs in bark crevices; no pair bond or parental care.

Behavior & Ecology

Social Solitary Group: 1
Activity Nocturnal, Crepuscular
Diet Folivore oak buds
Seasonal Hibernates

Temperament

Non-aggressive
Cryptic
Avoidant

Communication

sex pheromones
light attraction
tactile contact
contact chemoreception
substrate vibrations

Habitat

Deciduous Forest Woodland Forest Coniferous Forest Agricultural/Farmland Plantation Suburban Urban +2
Biomes:
Terrain:
Coastal Island Plains Valley Hilly Mountainous Riverine +1
Elevation: Up to 4921 ft 3 in

Ecological Role

Polyphagous folivore; outbreak defoliator shaping deciduous forest and orchard dynamics.

prey for birds energy transfer nutrient cycling

Diet Details

Other Foods:
Oak buds Apple leaves Birch leaves Maple buds Elm buds

Human Interaction

Domestication Status

Wild

Winter moth is not domesticated. It is a wild geometrid moth native to the Palearctic and introduced elsewhere as a pest; there is no documented history of human-directed breeding for any purpose.

Danger Level

Low
  • Harmless; no bite or sting
  • Moth scales may cause allergies
  • Indirect harm via tree defoliation

As a Pet

Not Suitable as Pet

Legality: Generally legal; often treated as a regulated pest.

Care Level: Experienced

Purchase Cost: Up to $25
Lifetime Cost: $10 - $75

Economic Value

Uses:
Forestry Agriculture Research
Products:
  • timber
  • fruit

Relationships

Predators 7

Great tit Parus major
Blue tit
Blue tit Cyanistes caeruleus
Pied flycatcher Ficedula hypoleuca
Common blackbird Turdus merula
Common pipistrelle Pipistrellus pipistrellus
European garden spider Araneus diadematus
Ground beetle
Ground beetle Carabidae

Related Species 5

Bruce spanworm moth Operophtera bruceata Shared Genus
Northern winter moth Operophtera fagata Shared Genus
Autumnal moth Epirrita autumnata Shared Family
Mottled umber Erannis defoliaria Shared Family
March moth Alsophila aescularia Shared Family

Ecological Equivalents 5

Animals that fill a similar ecological role in their ecosystem

Autumnal moth Epirrita autumnata Spring-feeding inchworm larvae defoliate birch and other deciduous trees.
Mottled umber Erannis defoliaria Adults are active late in the season; females are flightless; larvae feed on tree buds.
March moth Alsophila aescularia Flightless females climb trunks, and larvae browse emerging leaves of deciduous trees.
Spongy moth
Spongy moth Lymantria dispar Generalist spring defoliator of broadleaf trees; outbreaks can heavily damage canopies.
Green oak tortrix Tortrix viridana Larvae feed on expanding oak buds and young leaves in spring.

The Winter Moth is a type of moth that traveled from Europe and found its way into Canada and the United States. It comes from a community of moths that can survive in the seasons of late fall and winter. Hence, its name became Winter Moth. They are greyish yellow or brown in color, depending upon the type. In addition, only their males can fly while the females have shortened wings and locomote through their legs. 

Species, Types, and Scientific Name

The Winter Moth (Operophtera brumata) comes from the family Geometridae and of the order Lepidoptera. Its larvae form is often confused with the Cankerworms (Alsophila pometaria) and the Bruce spanworm (Operophtera bruceata) because of the similarity in their physical attributes. 

As per today’s research, only two known species exist of a Winter Moth. But the name Winter Moth is quite common and is often snatched by some scientists for naming certain similar moths. Apart from the (Operophtera brumata), Bruce spanworms (Operophtera bruceata) and linden loopers (Erannis tilaria) are also considered the Winter Moths in the US.

There are more than 160,000 moths around the world. But the estimated population size of the Winter Moth remains unknown. 

Here are the two known species of a Winter Moth;

  • Operophtera brumata
  • Operophtera bruceata

Appearance

The Winter Moth is one of the toughest moths in their community. It is known to come out in the winter season and aims to survive through it. If you wish to spot one, you can identify it based on its unique and mesmerizing physical attributes outlined below.

A Winter Moth has a base body color that may be different depending upon its type. The male gender is either greyish yellow in color or resembles a beige brown shade. Its body may have slight hints of the color red on top of this base color. The female, on the other hand, is more of a greyish brown color.

Apart from these “shades” on the body, there is a pattern of dark bands but they are not as distinct or visible from a far distance. The band may be dark brown in color. Both the genders are approximately 0.39 inches in length but the females are known to be shorter than the males. 

The Winter Moth has a pair of wings that are yellowish pale in color and with a wingspan of 0.86 to 1.10 inches. At the end of its body, there is a fringe that lines the bottom of the wings and is yellow in color. 

However, it is noteworthy that females have rudimentary wings and they are reduced as compared to that of males. Many scientists believe that females are wingless but that is not entirely true. Instead, the female Winter Moth has reduced wings and uses its hind legs as a way to move around. Both genders also have a pair of antennae that are short and hairy.

When it comes to the larvae, they are hatched from the eggs coming up to 1/10th of an inch. Imagine the length of an eyelash. They can grow up to 3/4th of an inch when they reach about six weeks. They are black in color with fine whitish pale vertical lines at both ends of the body as they grow older. 

When it comes to behavior, both the larvae and the adult moths portray different styles. The larvae of the Winter Moth are often found with similar larvae. They are never solitary. 

As for the adults, they are mostly found alone. They hunt and grow in solitude and are never found in groups. However, when the time comes to reproduce, the female and male moths will be seen together following the ritual of mating. 

Habitat: Where to Find the Winter Moth?

They are found in various parts of Europe. Recently, they traveled to Canada and the US. But they are found in the UK in abundance. Usually, the male Winter Moths come out in late fall and stay till February. During this time there are lesser predators and these moths have the stamina to survive through the cold season.

The female Winter Moths are usually seen on the trees, climbing atop the trunks, and waiting for the male moths to come and mate. They often climb with the help of their legs. But in some cases, you can find them producing silk threads that latch onto the neighboring trees, closer to their food source. Through these silk threads, they balloon themselves with the help of the air and move about. 

The Winter Moths have a special place for lights and are often seen near the lamps outdoors or near hedgerows. This is the reason many people spot these moths while driving. You may also spot one but you are likely to only find one or maybe two, but not in groups.

Life Cycle: How Do They Mate?

Since the females stay behind in the trees, they release pheromones. When it is sensed by the males, they are attracted to the females. After mating, females lay on average,150 to 300 eggs under the tree barks or near tree cervices, then die soon after.

After a six-week period, the eggs hatch. But the largest Winter Moth lays the most eggs. This is the reason that male Winter Moths are seen attracted to the largest female Winter Moth in the community. 

The eggs usually hatch in early Spring. They change into various colors during that time and are nearly blue when they hatch. It is found that the temperature of the surroundings is a trigger for these eggs to hatch. 

The young larvae are then prone to either feeding or locomoting through silk threads like you would find with adult female Winter Moths. The pupation occurs in the months of May but the adults do not emerge until it is November. Such a long period allows many predators to gobble them up. 

Diet

What does a Winter Moth Eat?

An interesting thing about a Winter Moth is that it usually feeds as a larva or a caterpillar. At that age, it is so small that it usually sticks to leaf buds as its main diet. But to be more specific, scientists have said that it feeds on broadleaved trees and shrubs, heather, and bog-myrtle. When a caterpillar has devoured a flower bud from within, it will move on and eat the next bud in line.  

What Eats Winter Moths?

Its predators are mainly wasps (Agrypon flaveolatum) and flies (Cyzenis albicans). Both the predators are usually fond of eating the caterpillar or the larvae form of the Winter Moth. 

The wasp lays eggs inside the larvae which then grow up to eat the Winter Moth from inside. Similarly, the fly is prone to laying eggs on the leaves. But these leaves are then eaten up by the Winter Moth caterpillars. And then the fly’s larvae usually end up digesting the Winter Moth after they hatch inside the Winter Moth.

Prevention: How to get rid of Winter Moths?

Winter Moths in their caterpillar forms can be quite hazardous to nature. Their feeding habit can sometimes become so deep that it leaves the plant unable to heal. Their main targets are apple, cherry, plum, and pear trees.

Sometimes, the attack is not enough to damage the plant and the damaged ends heal as the plant grows. But other times, the feeding may run too deep. 

Often, with a Winter Moth caterpillar, insecticides do not work. This is because they remain hidden under the buds, feeding on the flower buds. This allows them to remain protected. But many people use parasitic flies (Cyzenis albicans) against the Winter Moths.

Excess amount of water helps plants recover from the damage. Some people use oil sprays but it does not always come in handy apart from being used for fruit orchids.

Up Next…

Check out some of our other moth articles.

  • 10 Incredible Moth Facts – You won’t believe some of these!
  • Peppered Moth – Everything you want to know about this beautiful moth.
  • Comet Moth – One of the largest moths in the world!
View all 442 animals that start with W

Sources

  1. Wikipedia / Accessed July 19, 2022
  2. Butterfly Conservation / Accessed July 19, 2022
  3. The Daily Garden / Accessed July 19, 2022
  4. Mass Audubon / Accessed July 19, 2022
  5. U Mass / Accessed July 19, 2022
Alan Lemus

About the Author

Alan Lemus

Alan is a freelance writer and an avid traveler. He specializes in travel content. When he visits home he enjoys spending time with his family Rottie, Opie.
Connect:

Thank you for reading! Have some feedback for us?


Winter Moth FAQs (Frequently Asked Questions)

No, they do not have mouths. As most of their lives are spent on feeding as a larvae, their adult selves only seek to mate with each other.