Based on 3,002 research-grade iNaturalist observations in Illinois, Hackberry Emperor is most often recorded in August; in Illinois it behaves like a summer visitor / breeder. It ranks #14 among butterflies recorded in the state in our data.
Asterocampa celtis
Hackberry Emperor in Illinois by month
Bars show research-grade observations per month. They mix true seasonality with how often people are outdoors, so treat small numbers with caution.
Also seen in Illinois in August
Monarch
Eastern Tiger Swallowtail
Silver-spotted Skipper
Black Swallowtail
Pearl Crescent
Common Buckeye
Small White
Eastern Tailed-Blue
Places to look in Illinois
State ParkCahokia
Botanical GardenMorton Arboretum
National ForestShawnee National Forest
Botanical GardenChicago Botanic Garden
Botanical GardenLadd Arboretum
State ParkStarved Rock State Park
FAQ
When does Hackberry Emperor appear in Illinois?
Mainly June–August, with the most records in August.
How common is Hackberry Emperor in Illinois?
It ranks #14 by number of iNaturalist observations among butterflies in Illinois (3,002 records in our sample).