''Callosamia promethea'', commonly known as the promethea silkmoth, is a member of the family

Saturniidae Saturniidae, commonly known as saturniids, is a family of Lepidoptera with an estimated 2,300 described species. The family contains some of the largest species of moths in the world. Notable members include the emperor moths, royal moths, and gi ...

, which contains approximately 1,300 species. It is also known as the spicebush silkmoth, which refers to is one of the promethea silkmoth's common host plants,

spicebush Dried fruits of ''Lindera neesiana'' used as spice (coll. MHNT) ''Lindera'' is a genus of about 80–100 ''C. promethea'' is classified as a silk moth, which stems from its ability to produce silk, which it does in the formation of its cocoon. ''C. promethea'' lives in forests in the eastern U.S. and does not damage the trees on which it lives. The species was first described by

Dru Drury Dru Drury (4 February 1724 – 15 December 1803) was a British collector of natural history specimens and an entomologist. He had specimens collected from across the world through a network of ship's officers and collectors including Henry Sme ...

in 1773. ''Callosamia promethea'' hatches from eggs and feeds on its host plants before pupating while hanging from trees during the winter. It then emerges and mates during a specific time of day. The females utilize pheromones to attract males for mating, with both sexes mating multiple times. They are the only moth in their family where the sexes are not active at the same time of day, with males being diurnal and females being nocturnal. They only overlap in activity for a few hours in the early evening. The males use mimicry of the poisonous pipevine swallowtail butterfly as a form of protection from predators.

Distribution and habitat

The range of ''C. promethea'' extends the length of the

east coast of the United States The East Coast of the United States, also known as the Eastern Seaboard, the Atlantic Coast, and the Atlantic Seaboard, is the coastline along which the Eastern United States meets the North Atlantic Ocean. The eastern seaboard contains the coa ...

and west to the

Great Plains The Great Plains (french: Grandes Plaines), sometimes simply "the Plains", is a broad expanse of flatland in North America. It is located west of the Mississippi River and east of the Rocky Mountains, much of it covered in prairie, steppe, an ...

. ''C. promethea'' is found in deciduous forests.

Food resources

Caterpillar

''Callosamia promethea'' utilizes multiple plant families as their hosts, including

Rosaceae Rosaceae (), the rose family, is a medium-sized family of flowering plants that includes 4,828 known species in 91 genera. The name is derived from the type genus ''Rosa''. Among the most species-rich genera are ''Alchemilla'' (270), ''Sorbus ...

Oleaceae Oleaceae, also known as the olive family, is a taxonomic family of flowering shrubs, trees, and a few lianas in the order Lamiales, It presently comprises 28 genera, one of which is recently extinct.Peter S. Green. 2004. "Oleaceae". pages 296-30 ...

and

Lauraceae Lauraceae, or the laurels, is a plant family that includes the true laurel and its closest relatives. This family comprises about 2850 known species in about 45 genera worldwide (Christenhusz & Byng 2016 ). They are dicotyledons, and occur ma ...

. There is no negative effect to ''C. promethea'' larvae being raised on a host plant different from the one that their parents were raised on, for the specific host plants tested in the study. The nutritional content of the individual host plant matters more to the health of the larvae than feeding on a population’s typical host plant. Some examples of common host plants are the

tulip tree ''Liriodendron'' () is a genus of two species of characteristically large trees, deciduous over most of their populations, in the magnolia family (Magnoliaceae). These trees are widely known by the common name tulip tree or tuliptree for their ...

(''Liriodendron tulipifera''),

sassafras ''Sassafras'' is a genus of three extant and one extinct species of deciduous trees in the family Lauraceae, native to eastern North America and eastern Asia.Wolfe, Jack A. & Wehr, Wesley C. 1987. The sassafras is an ornamental tree. "Middle Eoc ...

(''Sassafrass albidum'') and

spicebush Dried fruits of ''Lindera neesiana'' used as spice (coll. MHNT) ''Lindera'' is a genus of about 80–100

Adult

''Callosamia promethea'' does not consume any food in its adult stage. Callosamia promethea larva

Life cycle

Egg

Callosamia promethea eggs and 1st instar

Female promethea silkmoths lay their eggs on the leaves of the host plants of the caterpillars. The eggs are laid at night. A female's eggs are laid in groups of 4 to 10 at a time. Eggs are white, flat and elliptical.

Caterpillar

Once the

caterpillar Caterpillars ( ) are the larval stage of members of the order Lepidoptera (the insect order comprising butterflies and moths). As with most common names, the application of the word is arbitrary, since the larvae of sawflies (suborder Sym ...

s hatch, they are fairly solitary. They eat leaves from the edge inwards. The caterpillars eat from several host plants. Caterpillars begin as yellow with black stripes, but become blue green over time. Once they are blue green, they develop four red and one yellow protuberances. These caterpillars go through several

instar An instar (, from the Latin '' īnstar'', "form", "likeness") is a developmental stage of arthropods, such as insects, between each moult (''ecdysis''), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or ass ...

s or skin shedding, and usually after the fifth shedding the caterpillar is ready to form a cocoon. When the caterpillars form cocoons, they are twice as long as they are wide.

Pupa

Some caterpillars in the family Saturniidae will

pupa A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their ...

te in the ground. However, promethea silkmoth caterpillars pupate in trees. The caterpillars attach themselves directly to the branches of trees with their silk. Then, they curl a dead leaf around themselves. ''C. promethea'' pupates during the winter.

Adult

The wingspan of this moth is . Like most Lepidoptera, females are on average larger than males. Males are darkly pigmented, while females are more brightly colored. The males and females both have tan on the edges of their wings. The males have a set of eyespots on their forewings, but the females have spots on all their wings. In the northern part of the promethea silkmoth's range, there is one brood per year and it occurs during the early summer. In the southern part of the moth’s range, there are two broods, with one occurring in the spring and the other occurring in late summer.

Predators

The location of the ''C. promethea'' cocoon typically provides the pupae with sufficient protection from possible predators. The cocoons hang from thin branches and are difficult to open, so mice may have difficulty predating because the branches are too thin to hold their weight and

woodpecker Woodpeckers are part of the bird family Picidae, which also includes the piculets, wrynecks, and sapsuckers. Members of this family are found worldwide, except for Australia, New Guinea, New Zealand, Madagascar, and the extreme polar regions. ...

s could have trouble opening the pupa. Other predators of the cocoons include some

flies Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advanced ...

and

wasp A wasp is any insect of the narrow-waisted suborder Apocrita of the order Hymenoptera which is neither a bee nor an ant; this excludes the broad-waisted sawflies (Symphyta), which look somewhat like wasps, but are in a separate suborder. Th ...

Protective coloration and behavior

Mimicry

''Callosamia promethea'' utilizes

Batesian mimicry Batesian mimicry is a form of mimicry where a harmless species has evolved to imitate the warning signals of a harmful species directed at a predator of them both. It is named after the English naturalist Henry Walter Bates, after his work on bu ...

, in which an edible species mimics a toxic species as a form of protection from predators. Promethea silkmoth females are rust and cream colored, but the males have very different coloration. Promethea silkmoth males mimic the pipe vine swallowtail (''Battus philenor''), a poisonous butterfly. The topside of the wings of promethea silkmoth males is black, as are the wings of the pipe vine swallowtails, which also have a shiny blue pattern on the top surface of their wings. The promethea silkmoth males do not have this reflective blue pattern, but their

mimicry In evolutionary biology, mimicry is an evolved resemblance between an organism and another object, often an organism of another species. Mimicry may evolve between different species, or between individuals of the same species. Often, mimicry f ...

is still effective due to the fact that the blue reflective pattern is only visible on pipe vine swallowtails in a certain light, so the blue is not essential for ''C. promethea'' mimicry to be effective. The effectiveness of this mimicry was tested experimentally. Promethea silkmoth males were painted with various patterns, then released, and the amount of each group that was recaptured showed that mimicry helped the moths survive. The control group was painted black, to match their actual coloration. One experimental group was painted black and yellow to mimic the tiger swallowtail (''Papilio glaucus''), which is not a poisonous butterfly and does not mimic the poisonous pipe vine swallowtail. The other experimental group was painted with orange stripes to mimic the poisonous monarch butterfly. The two groups that were painted to be mimetic to a poisonous butterfly both were recaptured more than the group painted to match an edible butterfly. This shows that mimicry, specifically the partial mimic of promethea silkmoth males to pipe vine swallowtails, is adequate protection against predation.

Mating

Female/male interactions

Pheromones

Female promethea silkmoths release

pheromone A pheromone () is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to affect the behavio ...

s to attract males. The females remain in place, camouflaged, as they wait for the males to sense their pheromones and come to them. Females release their pheromones at a specific time of day called the "calling time". For ''C. promethea'' this time is late afternoon and into the early evening. When males sense the pheromones of a female they travel up the gradient of the pheromones and towards the female. Males are able locate females from miles away. One ''C. promethea'' male has been found to be able to detect and find a female from 23 miles away. A distance this long is likely to be covered in multiple days.

Mate choice

In terms of locating mates, males cannot find females unless they release pheromones, so the females control how frequently they mate. When females do send out their pheromones, the first male to reach a female will mate with her.

Number of mates

''Callosamia promethea'' are

polyandrous Polyandry (; ) is a form of polygamy in which a woman takes two or more husbands at the same time. Polyandry is contrasted with polygyny, involving one male and two or more females. If a marriage involves a plural number of "husbands and wives" ...

, meaning the females mate with multiple males. However, not all females practice this behavior, some only mating with a single male. They are the only moth in the family Saturniidae known to be polyandrous. This is likely because ''C. promethea'' is the only moth that is both diurnal (males) and

nocturnal Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed sens ...

(females). This allows for egg laying and mating to occur at different times of day, so there is no trade off between the two activities. Male butterflies are

polygamous Crimes Polygamy (from Late Greek (') "state of marriage to many spouses") is the practice of marriage, marrying multiple spouses. When a man is married to more than one wife at the same time, sociologists call this polygyny. When a woman is ...

, as well. Polyandrous females are more

fecund Fecundity is defined in two ways; in human demography, it is the potential for reproduction of a recorded population as opposed to a sole organism, while in population biology, it is considered similar to fertility, the natural capability to pr ...

, due to laying more eggs. A female's eggs are mostly mature when they are laid.

Conservation

''Callosamia promethea'' is not endangered and there are no specific management practices in place to maintain or control the species.

Pest status

While these moths do live on many species of trees as a caterpillar they are not reported to cause any noticeable damage to their host trees.

Gallery

File:Callosamia promethea.jpg, Adult File:Callosamia promethea female.jpg, Adult female File:Callosamia promethea male.jpg, Adult male

References

External links

* {{Authority control Saturniinae Moths of North America Moths described in 1773 Taxa named by Dru Drury

Distribution and habitat

Food resources

Caterpillar

Adult

Life cycle

Egg

Caterpillar

Pupa

Adult

Predators

Protective coloration and behavior

Mimicry

Mating

Female/male interactions

Pheromones

Mate choice

Number of mates

Conservation

Pest status

Gallery

References

Further reading

External links