In the 1950’s a study was done in Louisiana that reported similar conditions as we are experiencing in our area. Other reports indicated that these same swarms have been happening and recorded since the 1880’s, all in southern regions. As recent as 2019 these swarms were reported in Northeastern, Kansas. Are weather patterns changing to such a degree that swarming behavior in these butterflies is now moving further north? We do know our winters are nowhere near the conditions we experienced decades ago. We have much less snow and ice and significantly warmer days for longer periods of time. This is bound to have an effect on plants and animals and their ability to survive and adapt. Is it having an effect on the hackberry butterfly in our area? Probably. Could these swarms become commonplace? Maybe.
Fortunately. this behavior is typically short-lived and should be over and done with in about 3 weeks. Until then we will have to tolerate this momentary butterfly apocalypse. They are harmless, and those landing in your personal space are seeking out the moisture and salt from your sweat, not to mention the males of this species are highly attracted to light or bright colored objects. Wearing a white t-shirt may act like a homing beacon for dozens of territorial males.
The hackberry emperors scientific name is Asterocampa celtis, Asterocampa translates to “star caterpillar” and is in reference to the star-like “antlers” at the front of the caterpillar that it shows when alarmed. The word celtis is the genus name for the hackberry tree. The feeding activity of these caterpillars is not known to cause long term damage to the trees, although smaller trees that are heavily populated with feeding caterpillars may become defoliated but should bounce back the next year. Treatment against the caterpillar is usually not needed or recommended. There are two generations of caterpillars in our area. The first generation is what we are experiencing now. The second generation will begin appearing in late summer or early fall. These caterpillars will overwinter in a curled-up leaf they stitch together with silk. Their body color will change to a brown shade to blend in with a dead leaf. In the spring they will become active again and begin feeding on the newly leafed trees and their bodies will change back to their former green color.
It is believed by some that the spirits, souls and departed loved ones piggyback on the wings of butterflies. These spirits travel the world visiting and checking in on those they left behind. When one lands on you, it is a past loved one letting you know they are near and watching over you. As you step outside into the swarm of butterflies over the next couple of weeks, whisper hello to those dearly departed souls, maybe they will hear.