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)


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)

  • Aquatic Biomes
  • rivers and streams

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)

  • Sexual Dimorphism
  • female larger


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)


Emperors breed seasonally. The reproduce sexually and lay eggs.


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)


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.

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)

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)


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)

Ecosystem Roles

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

Commensal/Parasitic Species

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


Deena Hauze (author), Animal Diversity Web Staff.



living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map


uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


an animal that mainly eats meat


uses smells or other chemicals to communicate


a period of time when growth or development is suspended in insects and other invertebrates, it can usually only be ended the appropriate environmental stimulus.

  1. active during the day, 2. lasting for one day.

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature


an animal that mainly eats leaves.


forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.


an animal that mainly eats fruit


An animal that eats mainly plants or parts of plants.


A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.


having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.


reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.


chemicals released into air or water that are detected by and responded to by other animals of the same species


Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).


an animal that mainly eats dead animals

seasonal breeding

breeding is confined to a particular season


remains in the same area


reproduction that includes combining the genetic contribution of two individuals, a male and a female


living in residential areas on the outskirts of large cities or towns.


uses touch to communicate


that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).


uses sight to communicate


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.