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

What do they look like?

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 front wings. They also have a row of blue-green eyespots on their hind wings. (Hall, 2019)

Larvae are green with patterns that vary by species. 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)

  • Sexual Dimorphism
  • female larger

Where do they live?

Emperors are a Nearctic genus of butterflies. They are found mainly in the United States. They are also found in Mexico and some Caribbean islands. (Johnson, 1988)

What kind of habitat do they need?

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

  • These animals are found in the following types of habitat
  • temperate
  • Aquatic Biomes
  • rivers and streams

How do they grow?

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. In their early stages of growth, larvae molt on the undersides of leaves or in leaf shelters. In some species, larvae in their third stage of growth spend the winter on the undersides of leaves or in leave shelters. (Hall, 2019; Hall and Butler, 2014)

How do they reproduce?

Emperors breed seasonally. The reproduce sexually and lay eggs.

How long do they live?

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)

How do they behave?

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.

How do they communicate with each other?

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)

What do they eat?

Adults of this genus are rarely seen feeding on flowers. Instead, they feed on rotting fruit, carrion, dung, and tree sap. They have been recorded feeding from snakewood trees. (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 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)

What eats them and how do they avoid being eaten?

When they feel threatened, larvae of some species will swing their spiny, spiky heads around. They will try to bite the threat with their mouthparts. Larvae are eaten by generalist predators. At least one species of tachinid fly and ichneumonid wasps are parasites that prey on them. (Hall, 2019; Hall and Butler, 2014)

What roles do they have in the ecosystem?

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

Commensal or parasitic species (or larger taxonomic groups) that use this species as a host

Do they cause problems?

Although rare, larvae of hackberry emperors may eat all of the leaves off of plants. Tawny emperors rarely have the numbers to hurt their host plants. (Hall and Butler, 2014)

How do they interact with us?

Emperors have no known positive economic importance to humans.

Are they endangered?

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


Deena Hauze (author), Animal Diversity Web Staff.


Hall, D. 2019. "Common name: tawny emperor butterfly" (On-line). Featured Creatures. Accessed August 02, 2020 at

Hall, D., J. Butler. 2014. "Common name: hackberry emperor" (On-line). Featured Creatures. Accessed August 02, 2020 at

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

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

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.

University of Michigan Museum of ZoologyNational Science Foundation

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Hauze, D. 2020. "Asterocampa" (On-line), Animal Diversity Web. Accessed March 03, 2024 at

BioKIDS is sponsored in part by the Interagency Education Research Initiative. It is a partnership of the University of Michigan School of Education, University of Michigan Museum of Zoology, and the Detroit Public Schools. This material is based upon work supported by the National Science Foundation under Grant DRL-0628151.
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