The tawny emperor is similar to the closely related and more common hackberry emperor (A. celtis), but it is more rust-colored, while the hackberry is a more neutral tan. Looking more closely, the upperside cell (the discal cell is the narrowly oval section at the front core of the forewing) of the tawny emperor has 2 dark, unbroken bars (this region on the hackberry emperor has one unbroken dark bar, while the inner dark “bar” is broken into 2 offset spots). Unlike the hackberry, the tawny’s forewing tips are not dark with white spots, and there is no distinct black spot on the forewing. Viewed from below, the hindwing has smudged, iridescent eyespots and is browner than that of the gray-brown hackberry, which has distinct eyespots.
Larvae are similar to those of the hackberry emperor: green with yellow-green and white stripes; the last segment is forked. The head is ringed with small fingerlike projects, and 2 larger projections on top of the head fork and resemble miniature deer antlers.
Habitat and Conservation
Caterpillars feed on the leaves of hackberry trees (genus Celtis). Missouri has three species: sugarberry (C. laevigata), dwarf hackberry (C. tenuifolia), and common hackberry (C. occidentalis).
The adults seldom visit flowers, but they do absorb nutrients from tree sap, rotting fruit, carrion, animal droppings, and damp sand or muddy ground. Like hackberry emperors, tawny emperors are attracted to sodium in human sweat, so they often alight on people.