A Promethea moth, also known as the Spicebush silkmoth or the Promethea silkmoth, lives in the Eastern United States and has several methods of protection against predators, including hanging the pupa on thin branches and excellent camouflage.
Promethea Moth species summary
| Scientific Name | Callosamia promethea |
| Family Name | Saturniidae |
| Kingdom | Animalia |
| Genus | Callosamia |
| Habitat | Open areas, deciduous woods |
| Range | The East Coast of the US, the Great plains |
| Host Plants | Sassafras, spicebush, white ash, tulip tree |
| Moth Description | Large, brown, with two eyespots on forewings and yellowish edge on forewings and hindwings |
| Caterpillar Description | Green, with 4 reddish horns on its head |
What does a Promethea moth look like?
The average wingspan of the Promethea moth is about 3 to 4 inches, which is about the size of an adult human hand, meaning it’s a large colorful moth.
The body of the female moth is black with reddish-brown or dark-brown wings. Their tan-shaded spots contain tan borders.
On the other hand, the thorax of the male is black with black wings and tan-shaded borders on the forewings and hindwings. The spread wings clearly display a postmedian line that crosses horizontally across the wings.
Males and females have one eyespot on both sides of the forewing edges. A thin white line separates the top half of the forewing and the hindwing from the bottom portion, regardless of gender.
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Promethea moth vs. Tulip Tree Silkmoth
There is a close resemblance between the Promethea moth (Callosamia promethea) to the Tulip tree silkmoth (Callosamia angulifera).
Both belong to the family Saturniidae and have similar wingspans and colors. However, the Promethea silkmoth caterpillar feeds on Rosaceae, Oleaceae, and Lauraceae, while Tulip tree silkmoth caterpillars feed on Liriodendron tulipifera. The Tulip tree silkmoth is also darker.
Promethea moth vs. Cecropia moth
The Cecropia moth is another one of the family Saturniidae, with colors similar to the Promethea moth. One significant difference includes the prominent bright spots on Cecropia’s wings.
Larva Description
Once they emerge from their eggs, Promethea caterpillars are yellow with black stripes that run along the length of the thorax. They will gradually change their appearance and turn blue-green after a few days.
They will also develop a yellow protuberance and four red spikes with black rims. They will turn a green shade after a few more instars.
A Promethea larva can grow around 1 to 3 inches (when fully stretched) once it reaches the fifth instar. Then, it will transition to the Promethea cocoon. It will spin the cocoon while hanging its body upside down in a leaf or stem of the host plant.
Preferred Habitat
The Promethea moth can live in the following types of surroundings:
- Deciduous woodlands
- Open areas
- Sandy tree groves
- Wet or dry spots
Usual Host Plants
Female Spicebush silkmoths lay their eggs on these food plants, and their larvae feed on them:
- Sassafras (Sassafras albidum)
- Spicebush (Lindera benzoin)
- White ash (Fraxinus americana)
- Tulip tree (Liriodendron tulipifera)
- Lilac (Syringa vulgaris)
- Sweetbay (Magnolia virginiana)
What is the Promethea moth’s diet?
Caterpillars feed on the host plants and store energy for later life cycles. The adult Promethea moth does not feed on any plant, tree, or flower.
Behavior and mating
The larva feeds on a wide variety of host plants to help it grow as fast as possible. After eating up all the leaves, they will proceed to consume the surrounding woody twigs with their powerful jaws.
Promethea moth larvae that are about to transition from the fifth instar attach their bodies to the tree branches using their spun silk. They also use dead leaves and cover the chrysalis as an added layer of protection.
These moths commonly undergo the pupal stage during the cold season as part of their overwintering method. This process may take somewhere between 5 days to 3 weeks.
A female Promethea moth secretes pheromones during the breeding season to draw the males towards her. She will wait in camouflage until a suitable mate visits her spot and initiates reproduction.
Females are considered polyandrous creatures and tend to mate with more than one male at a time. The Promethea moth lays 4 to 10 eggs at night.
Common Predators and the Promethea moth’s defense methods
Wasps and flies often attack the Promethea moth caterpillars. However, this moth has several defense mechanisms against predators. For example, the moth will play dead if disturbed. Combined with its camouflage, this defense method makes it almost invisible to predators.
Some predators will also have difficulty getting to the pupa. Woodpeckers will have a hard time penetrating the pupa since it’s hard, and a mouse won’t be able to climb the thin branches and take the chrysalis off the leaf.
Distribution
There are sightings of Promethea moths on the East Coast of the United States and the Great Plains.
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