Dryocampa rubicundarosy maple moth

Geographic Range

Rosy maple moths are native to North America. The northern extent of their range is in southern Canada, and they have been recorded in southern Ontario, Quebec, New Brunswick, Nova Scotia and Prince Edward Island. They range down the East Coast of the United States through most of Florida. Their range extends west to Michigan, Indiana, Texas, Kansas, and Nebraska. ("The Green Striped Maple Worm", 1971; Collins, et al., 1996; Cotinis, 2004; Forbes, 1960; Hyche, 2000; Oehlke, 2005; Opler, et al., 2012; VanDyke, 2006; Ward and Herbert, 1974)


Rosy maple moths inhabit temperate deciduous forests of eastern North America. They are most often associated with red maples (Acer rubrum), sugar maples (Acer saccharum), silver maples (Acer saccharinum), turkey oaks (Quercus laevis) and box elder maples (Acer negundo). Depending on where their host trees are, rosy maple moths have also been found in suburban areas. ("The Green Striped Maple Worm", 1971; Cotinis, 2004; Hyche, 2000; Opler, et al., 2012; VanDyke, 2006)

Physical Description

Adult rosy maple moths are extremely variable in color. Coloration in adults can range from unmarked white to bright yellow with dark pink maculation. The woolly body of rosy maple moths varies in color from bright yellow, to cream, to white. Their ventral side, legs, and antennae are usually rose pink. Upper wing color is also very variable; ranging from yellow to cream, to white with pink at the margins and bases of the wing. The amount of pink maculation on the wings ranges from dominant to nearly absent. Polymorphism does occur within different geographic regions. Unique to Missouri, subspecies alba is either all white or white with very faint pink maculation. (Collins, et al., 1996; Cotinis, 2004)

Sexual dimorphism is present in wing shape and span of rosy maple moths. Males have slightly narrower wings compared to females, and also have less rounded hindwings. Ornamentation differences are also present. Males have bipectinate antennae, while females have simple antennae. Both male and female rosy maple moths have an average wingspan of 32 to 55 mm. Male forewing length ranges from 17 to 29 mm. The last instar ranges from 38 mm to 55 mm in length. (Collins, et al., 1996; Cotinis, 2004; VanDyke, 2006)

Rosy maple moth caterpillars, also known as green-striped mapleworms, have different coloration depending on their stage of development. Early stage larvae have black heads and bodies that are yellowish-cream with faint longitudinal green stripes. Fully-grown caterpillars have beige to bright red heads. Their bodies are yellow-green with seven dark green lines running lengthwise. The longitudinal line coloration can also range from frosty blue to blue green, or black. Prominent black horns are located dorsally on the second thoracic segment. Two rows of short spines run along each side of the body and the terminal abdominal segments have four larger spines. Other moths in the same family (Saturniidae) have similar horned larvae, but lack the stunning color of rosy maple moths. ("The Green Striped Maple Worm", 1971; "The Greenstriped Mapleworm", 2010; Hyche, 2000)

  • Sexual Dimorphism
  • sexes alike
  • sexes shaped differently
  • ornamentation
  • Range length
    38 to 55 mm
    1.50 to 2.17 in
  • Range wingspan
    32 to 55 mm
    1.26 to 2.17 in


Female rosy maple moths lay their fertilized eggs 24 hours after mating on the underside of the host leaf and then depart. After 2 weeks, the larvae hatch. Rosy maple moth larvae go through five instar stages. During the first three instars, the larvae live and eat together. Only by the 4th instar do the larvae feed independently. During the early instars, the larvae have shiny black heads and yellow bodies with black dorsal lines running vertically. The second body segments of the larvae have two yellow tubercles, each terminating with two setae. Their bodies are sparsely covered with short setae. Their legs are black and have yellow tips. As they pass through the second and third instars, their body color and stripes begin to darken. Between 6 to 11 days after hatching, the brood molts and emerges with deeper colors, two long black dorsal horns near their head, and 6 short but sharp spines on the rest of the segments. About 12 days after hatching, the larvae undergo another molt. This molt leaves the larvae relatively the same in appearance. About 1 week later, the larvae undergo a third molt and emerge with brown heads and varied body colors. The body colors range from dark and light green, black and green, and black and yellow. Spotting also occurs in their first segments. Pupation occurs 10 to 14 days after the third molt. Pupae stages vary in length from 4 to 7 days. (Collins, et al., 1996; Eliot and Soule, 1902; Packard, 1893; VanDyke, 2006)


Mating behaviors of rosy maple moths are not well understood. Adults come out in the late afternoon or early evening and mate at night. Fertilization is internal. The following dusk, females lay their fertilized eggs. Females lay their eggs on the underside of host tree leaves, such as the leaves of the sugar maple tree (Acer saccharinum). Rosy maple moths have a polygyandrous mating system where females and males mate with different partners throughout the breeding season. For each new brood, rosy maple moth females find a different male. (Opler, et al., 2012; Packard, 1893; VanDyke, 2006)

Sexually mature adult rosy maple moths emerge from pupae from mid-May through mid-July. Oviposition peaks in early July. Rosy maple moths are oviparous, and females lay eggs 24 hours after internal fertilization by the male. Females lay 150 to 200 eggs after fertilization and deposit them in clusters of 10 to 30 on the underside of the host leaf. The larvae hatch after 2 weeks and live and feed gregariously until the final instars. Larvae feed until mid-August at the latest. Overwinter pupation can occur. If this happens, the pupae burrow into the soil and wait for more favorable conditions to emerge. Rosy maple moths are sexually mature at 2 to 9 months. ("The Greenstriped Mapleworm", 2010; Jervis, et al., 2005; Packard, 1893; VanDyke, 2006)

Egg-laying occurs at different times in the year depending on the region inhabited by the females. In Canada and northern regions of the United States, females lay one brood from May to August. In the southern states, females lay two broods from April to September. In the Deep South including Florida, females lay three broods from March to October. (VanDyke, 2006)

  • Breeding interval
    Rosy maple moths breed one to three times in a season, depending on the latitude of their host tree.
  • Breeding season
    Oviposition peaks in early July, though females living farthest south breed from March to October.
  • Range eggs per season
    150 to 200
  • Average gestation period
    24 hours
  • Range time to independence
    0 to 0 days
  • Range age at sexual or reproductive maturity (female)
    2 to 9 months
  • Range age at sexual or reproductive maturity (male)
    2 to 9 months

Parental care is nearly absent in rosy maple moths. During the 24 hours after fertilization but before the female lays her eggs, she will yolk and protect her eggs inside her body. Females lay their eggs on the underside of the leaves of the host tree and leave. Males do nothing more than fertilize the eggs. (Packard, 1893; VanDyke, 2006)

  • Parental Investment
  • female parental care
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female


Lifespan of rosy maple moths ranges from 2 to 9 months in the wild if overwinter pupation occurs. Typically, rosy maple moths raised in captivity have a shorter lifespan of around 2 to 5 months. In the wild, much of their life is spent overwintering in the pupal stage. In captivity, there is no need to overwinter due to unfavorable conditions. (Collins, et al., 1996; Eliot and Soule, 1902; Jervis, et al., 2005; VanDyke, 2006)

  • Typical lifespan
    Status: wild
    2 to 9 months
  • Typical lifespan
    Status: captivity
    1 to 3 months


Rosy maple moths are nocturnal and mainly solitary except during mating. Adults enter a stage of torpor during the morning and afternoon. They come out in the late afternoon and mate in the late evening. At night, females emit pheromones to attract males. Females lay eggs at dusk the day after mating. Adult rosy maple moths usually fly during the first third of the night. Early rosy maple moth larvae feed together but are not considered to feed in colonies. The larvae become solitary feeders as they develop into late-stage caterpillars. Fully-grown caterpillars use the winter to pupate in shallow holes underground. ("The Green Striped Maple Worm", 1971; Fullard and Napoleone, 2001; Opler, et al., 2012)

Home Range

Adult rosy maple moths inhabit a large range since they do not require food, but the exact size of the range is unknown. Larvae and caterpillars live on the same tree they hatched on. The larvae eat only the leaves and usually stay on the underside of the leaves. ("The Green Striped Maple Worm", 1971; "The Greenstriped Mapleworm", 2010; Collins, et al., 1996; Cotinis, 2004; Hyche, 2000; Opler, et al., 2012; Packard, 1893; VanDyke, 2006)

Communication and Perception

Sensory receptors of rosy maple moths are concentrated in the antennae, legs and palps. Adults use receptors to smell pheremones of the opposite sex when it is time to mate. Because adult rosy maple moths do not feed, their receptors are not used for finding food and are concentrated for reproductive purposes. Rosy maple moths are equipped with compound eyes and simple eyes, which allow them to see ultraviolet rays. However, the complexity of the eye changes with each developmental stage. Green-striped maple worms, their caterpillars, only have simple eyes that can differentiate between light and dark. Thus, their vision is poor. Adults and caterpillars both use their many setae to relay tactile information about their environment to the brain. Adults also use their body and antennae setae to sense the direction of the wind while flying. Rosy maple moths lack organs to process auditory sounds. As caterpillars and adults, rosy maple moths use their bright coloration as a warning sign and to seem distasteful to predators. (Bailey and Horn, 2007; Collins, et al., 1996; Fullard and Napoleone, 2001)

Food Habits

Adult rosy maple moths do not feed. The trees that females laid their eggs under become the host for the developing larvae. The early larvae feed in union, however, larvae become solitary feeders in the later stages. During the molting process, caterpillars feed on the undersides of the maple tree (Acer) or leaves of oak trees (Quercus). The larvae and caterpillars are folivorous, and consume the entire leaf blade. ("The Green Striped Maple Worm", 1971; Opler, et al., 2012; Packard, 1893)

  • Plant Foods
  • leaves


Rosy maple moths lay eggs on the underside of leaves so as to shield them from the eyes of hungry birds. Green-striped mapleworms exhibit aposematic coloring in their black spikes and red head. They also have cryptic coloration since they are a bright green; typically the color of the leaves they live and feed on. Adult rosy maple moths exhibit aposematic behavior with their bright yellow and pink coloring. Among bluejays (Cyanocitta cristata), black-capped chickadees (Parus atricapillus), and tufted titmouses (Parus bicolor), bluejays are the most successful predators of rosy maple moths. Field studies have shown that rosy maple moths have low acceptability to birds. The main predators of rosy maple moths and caterpillars are the local birds. ("The Green Striped Maple Worm", 1971; "The Greenstriped Mapleworm", 2010; Bailey and Horn, 2007; Collins, et al., 1996; Fullard and Napoleone, 2001; Sargeant, 1995)

Ecosystem Roles

Since adult rosy maple moths do not eat, they not impact the ecosystem as predators. Larvae and caterpillars, however, can be pests when occurring in large numbers on the leaves of maple and oak species, including sugar maples (Acer saccharum), red maples (Acer rubrum), silver maples (Acer saccharinum), elder box maples (Acer negundo), and oak trees (Quercus cerris). Several bird species prey on rosy maple moth larvae, but bird predation is not intense enough to slow the population buildup. Some parasites have accumulated in the larvae, such as one species of parasitic wasp (Hyposoter fugitivus) and one species of fly (Achaetoneura frenchii). The parasites are not abundant enough to affect the population size of the green-striped mapleworms. ("The Green Striped Maple Worm", 1971; "The Greenstriped Mapleworm", 2010; Opler, et al., 2012)

Species Used as Host
  • sugar maples (Acer saccharum)
  • red maples (Acer rubrum)
  • silver maples (Acer saccharinum)
  • elder box maples (Acer negundo)
  • oak trees (Quercus cerris)
Commensal/Parasitic Species

Economic Importance for Humans: Positive

There are no known positive economic impacts of rosy maple moths on humans.

Economic Importance for Humans: Negative

Adult rosy maple moths are not known to have negative economic impacts on humans. However, larvae are defoliators capable of defoliating their host trees during a population explosion. If two generations are produced in a single year, host trees can be completely stripped of leaves twice. Typically this does not kill or permanently damage the tree. Nonetheless, this can defoliate acres of trees in a short time period if accompanied by another other hardwood defoliator, saddled prominent moths (Heterocampa guttivitta). In addition rosy maple moth larvae can be a nuisance to decorative trees as house pests. ("The Green Striped Maple Worm", 1971; "The Greenstriped Mapleworm", 2010; Collins, et al., 1996; Cotinis, 2004; Covell, 1984; Fullard and Napoleone, 2001; Hyche, 2000; Oehlke, 2005; Opler, et al., 2012; VanDyke, 2006)

  • Negative Impacts
  • household pest

Conservation Status

Rosy maple moths are not considered threatened or endangered. (VanDyke, 2006)


Alicia Damele (author), University of Michigan-Ann Arbor, Catherine Kent (editor), Special Projects.



living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map


having coloration that serves a protective function for the animal, usually used to refer to animals with colors that warn predators of their toxicity. For example: animals with bright red or yellow coloration are often toxic or distasteful.


Referring to an animal that lives in trees; tree-climbing.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


uses smells or other chemicals to communicate


having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.


animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

female parental care

parental care is carried out by females


union of egg and spermatozoan


an animal that mainly eats leaves.


forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.


An animal that eats mainly plants or parts of plants.


the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.

internal fertilization

fertilization takes place within the female's body


A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.


having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.


active during the night


reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.


chemicals released into air or water that are detected by and responded to by other animals of the same species


the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.


"many forms." A species is polymorphic if its individuals can be divided into two or more easily recognized groups, based on structure, color, or other similar characteristics. The term only applies when the distinct groups can be found in the same area; graded or clinal variation throughout the range of a species (e.g. a north-to-south decrease in size) is not polymorphism. Polymorphic characteristics may be inherited because the differences have a genetic basis, or they may be the result of environmental influences. We do not consider sexual differences (i.e. sexual dimorphism), seasonal changes (e.g. change in fur color), or age-related changes to be polymorphic. Polymorphism in a local population can be an adaptation to prevent density-dependent predation, where predators preferentially prey on the most common morph.

seasonal breeding

breeding is confined to a particular season


reproduction that includes combining the genetic contribution of two individuals, a male and a female

sexual ornamentation

one of the sexes (usually males) has special physical structures used in courting the other sex or fighting the same sex. For example: antlers, elongated tails, special spurs.


lives alone


living in residential areas on the outskirts of large cities or towns.


uses touch to communicate


that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).


uses sight to communicate


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