Asterocampa celtis

The larvae of A. celtis feed upon the leaves and leaf buds of hackberry trees. They must first climb back up their host tree to eat after they are done hibernating over winter. The caterpillars have been known to eat so much at a time that they can completely defoliate a tree.[3][7]

Leaves of a hackberry tree

Adults feed on a variety of food sources. They seldom make visitations to flowers so nectar is not a primary food source. Instead, they commonly eat hackberry sap, feces, dead animals including decaying pigs, snakes, and dogs, and old fruit.[8] They drink from water in puddles. Also, they are known to land on humans to lick off their sweat to gain sodium.[3][6]

A. celtis usually lays eggs in clusters on the underside of hackberry leaves, although it has been observed to occasionally lay eggs on the top of a leaf. Laying eggs in clusters results in higher fecundity for the female. Some factors influencing oviposition could be that laying eggs in a large cluster decreases the time and energy necessary for searching for new leaf sites, which decrease the risk of maternal death between oviposition events. For A. celtis, laying eggs in clusters is its best strategy to produce the most offspring.[5][7]

The pale eggs are laid in clusters of 5-20 eggs on the host plant.[9] Eggs look white with a faint green-yellow hue.

The body is approximately 1.4" long. The head has brown-black colored dorsal horns. The body is a primarily green with whitish-yellow chalazae, or bumps. At the rear, two sharp tails protrude outwards level with the abdomen.

Half-grown larvae hibernate over the winter in fallen hackberry leaves along the forest floor. In the spring, they emerge again and climb back up the hackberry tree to eat the foliage.[3][7]

Pupae have a dark green color with white spots all around the body. There are also white lines going diagonally across the abdomen.[3]

Pupae are found on the underside of hackberry leaves and metamorphose into adults in the early summer.[7]

A. celtis adults exhibit sexual dimorphism. Males have smaller, darker bodies and more slender wings than females. Both males and females are light brown with a row of black or white dots near the far edge of their wings. White spots near the front of the wing help distinguish it from a similar butterfly, the Tawny Emperor.[3][6]

Adult hackberry emperors lay two broods in a year. This production of multiple generations within one year makes it such that all life stages may be present at one time within a single site or host tree.[7]

Generalist species like birds and mammals, such as bears and raccoons, will eat larvae that lie along the forest floor. The stink bug is also a very common predator of hackberry emperor eggs.[6][10]

Scelionid egg parasites antagonize many species of Asterocampa, including the hackberry emperor. A tachinid fly parasitoid, Chetogena edwardsii, is another common threat to the hackberry emperor.[10]