What does the caterpillar look like?

Green with pale stripes, two barbed horns on the head and two tail points.

Hackberry Emperor: The Brown Butterfly of Hackberry Trees

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Caterpillars grow to 1 to 1 1/2 inches, yellow-green to green with pale yellow-white stripes, two barbed horns on the head and two short tails at the rear.^[1][2]
Adults are brownish with white and black spots and fly very fast; males perch on host trees to wait for females.^[1]

Common in river bottoms and other areas where hackberry is common; dense swarms have been recorded in some southern states.^[1]

US map: public records from 33 states since 1990 (GBIF).

There are two generations a year in most of the range and possibly three in Florida; caterpillars are present from early summer to fall.^[1][2]

None to people or pets.^[1][2]

No control is needed.^[1][2]

What is the brown spotted butterfly near my hackberry tree?: Likely a hackberry emperor.^[1][2]
What does the caterpillar look like?: Green with pale stripes, two barbed horns on the head and two tail points.^[1][2]
Is it a pest?: No.^[1][2]

University of Florida IFAS Extension (EDIS, Featured Creatures), “Hackberry Emperor, Asterocampa celtis (EENY-453/IN820).” ask.ifas.ufl.edu/publication/IN820 (accessed 2026-10-15)
University of Missouri Extension (Caterpillars in Your Yard and Garden, IPM1019), “Caterpillars in Your Yard and Garden, page 22: Hackberry emperor.” extension.missouri.edu/publications/ipm1019-22 (accessed 2026-10-15)
iNaturalist, “Asterocampa celtis taxon page (order and family).” www.inaturalist.org/taxa/68264 (accessed 2026-10-06)

Updated 2026-10-16. Built from sourced records. Spot an error? Tell us.