Hyalophora cecropia

Geographic Range

Cecropia moths ( Hyalophora cecropia ) are a Nearctic species with a wide range that extends throughout the eastern half of the United States and the southern Canada. In Canada, they can be found as far north as the 50th parallel and as far east as Nova Scotia. In the United States, cecropia moths can be found as far south as the 27th parallel in central Texas and Florida. Rare sightings of these moths have also been reported throughout the western half of the United States.

• Biogeographic Regions
• nearctic nearctic
  • native native

Habitat

Across their wide range, cecropia moths are found in temperate forests in rural to urban areas on younger hardwood trees. They are found in backyards, orchards, fencerows, new housing developments, and woodland areas. Bouseman and Sternburg (2002) state that while some cecropia moth cocoons can be found on the branches of deciduous trees, most are found under them in tufts of grass or shrubs. This is thought to help cecropia moths avoid predation. Elevation is not recorded for this species.

• Habitat Regions
• temperate temperate
• terrestrial terrestrial

• Terrestrial Biomes
• forest forest

• Other Habitat Features
• urban urban
• suburban suburban
• agricultural agricultural

Physical Description

Larvae of cecropia moths start out as mottled brown eggs, and when they emerge the larvae are black and weigh approximately 3.7mg, the first time they molt they become yellow with black and spiny scoli. From the third to fifth phase of molting, or instar, the larvae are pale green with orange or red pairs of scoli on the meta and mesothoracic segments, with blue lateral and yellow dorsal and ventral scoli along the rest of the body. Fully grown larvae will reach a length of around 100mm and a weight of approximately 10.2g - a 2760-fold increase in size.

The larvae spins a two-layered brown silk cocoon with the space between filled with silk; each layer contains an exit valve facing skyward and oriented perpendicular to the horizontal plane. The outer layer of the cocoon is spun in one of two distinct forms: baggy or tight. Lab tests show that environmental factors do not determine whether a larvae will spin one or the other, and that both contain the same amount of silk. Guerra and Reppert (2017) state that there is no known clear reason for the two types of cocoons, but theorize it to be a strategy to wager for the unknown conditions of the next winter.

Adult cecropia moths are very large with a broad wingspan of 110 to 180mm. The base wing color is black with white scales dispersed within. Each wing has a white, sometimes reddish, crescent eyespot. The base of the forewing is red with a white band followed by a black band in the middle of it. The wing margins are a khaki color, and the tip of the forewing has a purple smear with a black spot next to it. Between the eyespots and margins of both wings is a white then red band. Both sexes are similar in color with hairy bodies that are rusty red with white bands. Adults of this species lack mouthparts.

For all members of the Family Saturniidae, the cubitus in the forewing, or fifth longitudinal vein, branches into three veins that continue to the edge of the wing. While the hindwing only has one anal vein, and the angle of the first three veins deviates from base of the wing. Members of this family also have a small or vestigial frenulum, or bristle that holds the wings together.

The only discernable difference between sexes of cecropia moths is the size of the antennae: males have much larger quadripectinate antennae than females, this helps the males detect pheromones produces by the females.

• Other Physical Features
• ectothermic ectothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• sexes alike
• ornamentation ornamentation

Development

Cecropia moths begin their development as mottled brown eggs. When they hatch, the larvae are black. At the first molt (instar) they become yellow with spiny black structures called scoli. From the third to fifth instars, the larvae are pale green with orange or red pairs of scoli on the meta- and mesothoracic segments, with blue lateral and yellow dorsal and ventral scoli along the rest of the body.

During the fifth instar, the silk glands grow and start synthesizing silk. They will stop eating and begin spinning a double-walled cocoon. The larvae molt a final time into pupae. The pupae enter diapause to halt their development to survive winter. The pupae require eight to ten weeks at temperatures below 15°C to condition themselves to emerge at the correct time as adults; 5-20% of pupa will exit diapause and begin development as soon as temperatures warm, the remaining pupa require a month or more of warm temps to begin development. The mature adults emerge from their cocoons before searching for a mate. Adults do not eat, instead surviving on fat stores for one to two weeks until they expire.

• Development - Life Cycle
• metamorphosis metamorphosis
• diapause diapause

Reproduction

Cecropia moths are polygynous; female moths will mate with the first male that reach them while the males mate with multiple females. The female moths emerge from the cocoon with a full set of mature eggs and will wait until a few hours before dawn to release pheromones. After three days females lay eggs in groups between two and ten. Male cecropia moths use large quadripectinate antennae to follow pheromone trails upwind in a zig-zag pattern until they find a mate. Once males find a mate, copulation begins without courtship. A pair can mate for 24 hours unless disturbed, but usually from morning to evening, when the pair separates and the females begin searching for host plants to deposit eggs.

• Mating System
• polygynous polygynous

Cecropia moth females breed once during their short time as adults. Three days after emerging from their cocoons, in either May or late June-early July, the adult female moths will begin laying eggs to save energy and reduce carry weight. After mating, the female will begin laying fertile egg clutches on the leaves of host plants. The females will lay on average 300 eggs (range 80-400), laying 36% of their eggs the first day, then laying a smaller percent of eggs every day for the next few days. The eggs hatch with an average weight of 3.7mg and are immediately independent. Both sexes reach adulthood after 11-13 months after hatching.

• Key Reproductive Features
• semelparous semelparous
• sexual sexual
• fertilization fertilization
  • internal internal
• oviparous oviparous
• sperm-storing sperm-storing
• delayed fertilization delayed fertilization

Male cecropia moths do not provide parental care beyond the act of mating. Female cecropia moths do not provide parental care beyond egg-laying of small clutches on host plants over a broad area.

• Parental Investment
• no parental involvement

Lifespan/Longevity

Cecropia moths are a univoltine species with a single generation per year. The larvae have a bimodal emergence that is not reproductively isolated; some of the eggs will hatch up to two months later than others in the same clutch. The moths reach adulthood after 11-13 months after hatching and typically live for 10 days (range 5-12 days). There is no known difference in lifespan in captivity.

Limiting factors of the cecropia moth lifespan include fungal, bacteria, and viral infections. Fungal infections typically occur during inactive periods such as diapause or molting, quickly suffocating the moth. Mass applications of the bacterium, Bacillus thuringiensis , used to suppress pest caterpillars, can inadvertently cause high mortality in nontarget lepidopteran species. Lastly, infections from nuclear polyhedrosis and granulosis viruses have been reported in members of the genus.

Behavior

Cecropia moths are insects whose behavior is defined by a yearly cycle separated into its four stages of development: egg, larva, pupa, and adulthood. The motile stages are mostly nocturnal and crepuscular, but sometimes diurnal. The life of cecropia moths begins in late spring or early summer as sedentary eggs on a leaf of a host plant. The eggs hatch in a clutch of two to ten larvae that feed together until the second instar (phase) when the larvae become solitary for the rest of their lives. The larval stage is spent climbing and eating a host tree or shrub, growing, and molting through five instars. During the fifth instar the larvae spin cocoons and molt into a pupa, which enter diapause to halt development during winter. Bouseman and Sternburg (2002) state that cecropia moths have a bimodal emergence: 5 to 20% of pupae emerge once temperatures warm and they become adults in May, while the remaining 80 to 95% require another month of warm temperatures to develop, emerging in late June and early July. The adults emerge from their cocoons in late morning and expand their wings to fly. Males spend most of the adult stage flying in search of a mate, and females spend most of the adult stage flying in search of new host plants and laying eggs. The adult stage lasts approximately ten days (range 5 to 12).

• Key Behaviors
• arboreal arboreal
• flies
• diurnal diurnal
• nocturnal nocturnal
• crepuscular crepuscular
• motile motile
• sedentary sedentary
• solitary solitary
• social social

Home Range

The home range of the larval stage of cecropia moths are limited to a single host plant or adjacent plants, though the area they use has not been quantified. Adults cecropia moths don't have a home range or defend a territory; they typically live for 10 days (range 5-12 days), and can travel and far as 78 km and 42 km for males and females, respectively.

Communication and Perception

Like all members of the saturniidae family, cecropia moths use vision, touch, taste, and smell to perceive their surroundings, and primarily use their sense of smell and pheromones to communicate. After emerging from their cocoons and waiting until after dusk, females stay put and release pheromones, while males will use their large and featherlike antennae to seek out females by flying upwind in a zig-zag pattern before directly homing in on a female. In general, moth pheromones comprise of alcohols, aldehydes, or acetates, yet the composition of saturniid moth pheromones is not well understood. Closely related moths will use similar pheromone molecules but use a unique ratio of those molecules to identify members of their species.

• Communication Channels
• chemical chemical

• Other Communication Modes
• pheromones pheromones

• Perception Channels
• visual visual
• tactile tactile
• chemical chemical

Food Habits

Cecropia moth larvae are polyphagous folivores that feed on the leaves of a large variety of deciduous trees and shrubs. The plants they consume include apples ( Malus ), ashes ( Fraxinus ), beeches ( Fagus ), birches ( Betula ), cherries ( Prunus ), dogwoods ( Cornus ), maples ( Acer ), larch ( Larix ), poplars ( Populus ), and willows ( Salix ). The short-lived adults survive off fat stores and have no need for mouthparts.

• Primary Diet
• herbivore herbivore
  • folivore folivore

• Plant Foods
• leaves

Predation

Most cecropia moth larvae do not reach adulthood and fall prey to many species. Over 75% of larvae are eaten before they reach the late instars. Invertebrate predators include spiders (Order Araneae), wasps (Order Hymenoptera), and true bugs (Order Hemiptera). During the winter ca. 90% of cocoons on trees are eaten by downy woodpeckers ( Dryobates villosus ) and hairy woodpeckers ( Dryobates pubescens ), who use their beaks to poke a hole through the cocoon and suck out the soft tissues. Black-capped chickadees ( Parus atricapillus ) also have been reported to cut open cocoons and consume contents. Cocoons spun on shrubs show an over 80% survival rate, as they provide more concealment for the insects. Eastern gray squirrels ( Sciurus carolinensis ) eat the pupae, and in rural areas white-footed mice ( Peromyscus leucopus ) eat the pupae in these cocoons spun close to the ground. To avoid predation, cecropia moth larvae possess bright and spiny scoli that may deter predators, but larvae rely primarily on their green coloration to stay hidden among leaves and will remain motionless when disturbed. Adults have eyespots on their wings that resemble vertebrate eyes. When disturbed, they will display them to deter predators.

• Anti-predator Adaptations
• cryptic cryptic

Ecosystem Roles

Cecropia moths convert plant chemical energy into food for predatory species such as spiders, insects, rodents, and birds.

Cecropia moths are known hosts of common endoparasites of saturniid moths including tachinid flies ( Compsilura concinnata ), braconid wasps ( Cotesia ), ichneumonid wasps (Family Ichneumonidae), and chalcid wasps (Superfamily Chalcidoidea). Cecropia moths have also been reported to have been infected by fungal microsporidia from the genera Thelohania and Nosema .

Economic Importance for Humans: Positive

Cecropia moths are a common model species in laboratory and field research, and often brought into classrooms for learning. Cecropia moths are easy to raise and mate in captivity if given plenty of host plant material. In addition, the cocoons of the species are easy to identify and collect in areas of human development.

• Positive Impacts
• research and education

Economic Importance for Humans: Negative

There are no known negative economic effects of cecropia moths on humans.

Conservation Status

Cecropia moths are either not evaluated or have no special status on the IUCN Red list, US Federal List, CITES, or the State of Michigan List.

Threats to cecropia moths include urban development, the use of pest control on ornamental trees and shrubs, and the introduction of parasitoid species such as the tachinid fly ( Compsilura concinnata ). Boettner et al. (2000) state that anecdotal descriptions from the 19th century by collectors describe local population densities of cecropia moths much higher than found today, suggesting the use of DDT, the decline of host trees, and mercury lamps as culprits.

There are no known conservation efforts to preserve cecropia moths as populations are considered stable. The eradication of DDT and efforts in forest regeneration undoubtably impact these moths in a positive manner.

Additional Links

Encyclopedia of Life

Contributors

Elias Vance (author), Radford University, Candice Amick (editor), Radford University, Katherine Gorman (editor), Radford University, Karen Powers (editor), Radford University.

References

Beadle, D., S. Leckie. 2012. Peterson Field Guide to Moths of Northeastern North America . New York, New York: Houghton Mifflin Harcourt.

Boettner, G., J. Elkinton, B. Boettner. 2000. Effects of a biological control introduction on three nontarget native species of Saturniid moths. Conservation Biology , 14/6: 1798-1806.

Borror, D., R. White. 1970. Peterson Field Guides Insects . New York, New York: Houghton Mifflin Company.

Bouseman, J., J. Sternburg. 2002. Field Guide to Silkmoths of Illinois . Champaign Illinois: Illinois Natural History Survey.

Covell, C. 2005. A Field Guide to the Moths of Eastern North America . Martinsville, Virginia: Virginia Museum of Natural History.

GBIF, S. 2022. "Hyalophora cecropia Linnaeus, 1758" (On-line). gbif.org. Accessed February 02, 2023 at https://www.gbif.org/species/1865839 .

Guerra, P., S. Reppert. 2017. Dimorphic cocoons of the cecropia moth (Hyalophora cecropia): Morphological, behavioral, and biophysical differences. PLoS ONE , 12/3: e0174023. Accessed February 09, 2023 at 10.1371/journal.pone.0174023 .

Hanegan, J., J. Heath. 1970. Activity patterns and energetics of the moth, Hyalophora cecropia. The Journal of Experimental Biology , 53/3: 611-27.

Leckie, S., D. Beadle. 2018. Peterson Field Guide to Moths of Southeastern North America . New York, New York: Houghton Mifflin Harcourt.

Lees, D., A. Zilli. 2019. Moths Complete Guide to Biology and Behavior . Washington, DC: Smithsonian Books.

Marshall, S. 2006. Insects Their Natural History and Diversity . Buffalo, New York: Firefly Books Ltd.

Nechols, J., P. Tauber. 1982. Thermal requirements for postdiapause development and survival in the giant silkworm, Hyalophora cecropia (Lepidoptera: Saturniidae). Journal of the New York Entomological Society , 90/4: 252-257.

Powell, J., P. Opler. 2009. Moths of Western North America . Berkeley, California: University of California Press.

Rau, P., N. Rau. 1913. The fertility of cecropia eggs in relation to the mating period. Biological Bulletin , 24/4: 245-250.

Riddiford, L., J. Ashednhurst. 1973. The switchover from virgin to mated behavior in female cecropia moths: The role of the bursa copulatrix. Biological Bulletin , 144/1: 162-171.

Stamp, N., T. Casey. 1993. Caterpillars Ecological and Evolutionary Constraints on Foraging . New York, New York: Chapman and Hall.

Tuskes, P., J. Tuttle, C. Michael. 1996. The Wild Silk Moths of North America . Ithaca, New York: Cornell University Press.

Wagner, D. 2005. Caterpillars of Eastern North America: A Guide to Identification and Natural History . Princeton, New Jersey: Princeton University Press.

Waldbauer, G., J. Sternburg. 1967. Differential predation of cocoons of the Hyalophora cecropia (Lepidoptera: Saturniidae) spun on shrubs and trees. Ecology , 48/2: 312-315.

Waldbauer, G., J. Sternburg. 1979. Inbreeding depression and a behavioral mechanism for its avoidance in Hyalophora cecropia. The American Midland Naturalist , 102/1: 204-208.

Young, A. 1982. Predation on the pupae of Saturniidae (Lepidoptera) by gray squirrels in Wisconsin. Great Lakes Entomologist , 15/2: 145.