Animal Diversity Web

Diversity

Asterocampa, commonly known as emperor butterflies, are a genus made up of four species, including tawny emperor butterflies, hackberry emperor butterflies, cream-banded emperor butterflies, and empress leilia butterflies. Each of these species contains up to four subspecies. (Johnson, 1988; Pelham, 2008)

Geographic Range

Emperors are a Nearctic genus of butterflies. They are also found in Mexico and the Antilles. (Johnson, 1988)

• Biogeographic Regions
• nearctic
  • native

Habitat

Adults are typically found on their food plants. Some species of this genus, like tawny emperors, can be found in riparian forests, dry forests, and suburban areas. Hackberry emperors are found at river ends. (Hall, 2019; Johnson, 1988)

• Habitat Regions
• temperate

• Terrestrial Biomes
• forest

• Aquatic Biomes
• rivers and streams

• Other Habitat Features
• suburban
• riparian

Physical Description

Species of this genus are typically brown, tan, or orange with black patterns. Males are smaller than females. One species, hackberry emperors, have black eyespots on their forewings. They also have a row of blue-green eyespots on their hind wings. (Hall and Butler, 2014)

Larvae are green with patterns that vary by species. All larvae of this genus have spiky horns. Pupae are green on color. Eggs are white or pale yellow in color. (Hall, 2019; Hall and Butler, 2014)

• Other Physical Features
• ectothermic
• bilateral symmetry

• Sexual Dimorphism
• female larger

Development

Depending on the species, eggs are laid in singly, in small batches, or in large batches. Often found on the undersides of leaves or on the bark of trees. After hatching, larvae move as a group to food sources. Each group of larvae lays down a trail of silk for other larvae to follow. This allows larvae to safely reach new feeding areas. Early instars of larva molt on the undersides of leaves or in leaf shelters. In some species, third instar larvae overwinter on the undersides of leaves or in leave shelters. (Hall, 2019; Hall and Butler, 2014)

• Development - Life Cycle
• metamorphosis
• diapause

Reproduction

Emperors breed seasonally. The reproduce sexually and lay eggs.

• Key Reproductive Features
• seasonal breeding
• sexual
• oviparous

Lifespan/Longevity

Depending on the species and location, there may between one and four generations per year. Larvae create leaf shelters and undergo diapause during cold months. (Hall, 2019; Hall and Butler, 2014)

Behavior

Emperors butterflies are able to fly and glide. They are active during the day. Staying mainly in one area, emperors do not travel long distances.

• Key Behaviors
• flies
• diurnal
• motile
• sedentary

Communication and Perception

Emperor butterflies have compound eyes. Like other butterflies, they are able to see ultraviolet light. Their antennae are sensory organs; they allow the butterflies to sense odors, touch, and possibly sound. They have taste receptors in their mouths and on the bottoms of their feet. Butterflies are able to perceive sound, though they do not have a special organ dedicated to this sense as moths do. (Wernert, 1998)

• Other Communication Modes
• pheromones

• Perception Channels
• visual
• ultraviolet
• tactile
• acoustic
• chemical

Food Habits

Adults of this genus are rarely observed feeding on flowers. Instead, they feed on rotting fruit, carrion, dung, and tree sap. They have been recorded feeding from the snakewood trees. (Hall, 2019; Neck, 1983)

Caterpillars feed on their host plants. Larvae of both hackberry butterflies and tawny emperors feed on hackberry trees and southern sugarberry trees. Larvae of hackberry butterflies tend to feed on old foliage. Larvae of tawny emperors feed on new foliage. By feeding on different ages of foliage, these two species are able to avoid competition with each other. (Hall, 2019; Neck, 1983)

• Primary Diet
• carnivore
  • scavenger
• herbivore
  • folivore
  • frugivore

Predation

When they feel threatened, larvae of some species will swing their spiny, spiky heads around. They will try to bite the threat with their mandibles. Larvae are preyed upon by generalist predators. They are parasitized by at least one species of tachinid fly and ichneumonid wasps. (Hall, 2019; Hall and Butler, 2014)

• Known Predators

  • tachinid flies (Chetogena edwardsii)
  • ichneumonid wasps (Microcharops tibialis)

Ecosystem Roles

Emperors are parasitized by tachinid flies and ichneumonid wasps. (Hall, 2019; Hall and Butler, 2014)

Economic Importance for Humans: Positive

Emperors have no known positive economic importance to humans.

Economic Importance for Humans: Negative

Although rare, larvae of hackberry emperors may cause complete defoliation of their host plants. Tawny emperors rarely have the numbers to impact their host plants. (Hall and Butler, 2014)

Conservation Status

Some species of this genus are the target of conservation efforts. Most populations are stable. (Hall, 2019; Hall and Butler, 2014; Pelham, 2008)

• IUCN Red List [Link]

  Not Evaluated

Contributors

Deena Hauze (author), Animal Diversity Web Staff.

References

Hall, D. 2019. "Common name: tawny emperor butterfly" (On-line). Featured Creatures. Accessed August 02, 2020 at http://entnemdept.ufl.edu/creatures/bfly/bfly2/tawny_emperor.htm.

Hall, D., J. Butler. 2014. "Common name: hackberry emperor" (On-line). Featured Creatures. Accessed August 02, 2020 at http://entnemdept.ufl.edu/creatures/bfly/hackberry_emperor.htm.

Johnson, K. 1988. Reviewed Work: Taxonomy, Phylogeny, and Biogeography of Asterocampa Röber 1916 (Lepidoptera, Nymphalidae, Apaturinae). Journal of the New York Entomological Society, 96(4): 482-485. Accessed July 31, 2020 at https://www-jstor-org.ezproxy2.library.colostate.edu/stable/25009719.

Neck, R. 1983. SIGNIFICANCE OF VISITS BY HACKBERRY BUTTERFLIES (NYMPHALIDAE: ASTEROCAMPA) TO FLOWERS. Journal of the Lepidopterists' Society, 37(4): 269-274. Accessed July 31, 2020 at https://images.peabody.yale.edu/lepsoc/jls/1980s/1983/1983-37(4)269-Neck.pdf.

Pelham, J. 2008. A catalogue of the butterflies of the United States and Canada with a complete bibliography of the descriptive and systematic literature. Journal of Research on the Lepidoptera, 40: 685.

Wernert, S. 1998. Reader's Digest North American Wildlife. New York: Readers Digest.