Hackberry Extravaganza by Claire Curry
There’s a swarm of bugs outside my house. They land on me when I go out, probing with their proboscises. Some will ride around on me as I walk around the yard, while others only pause for a moment. What are these insects? Not mosquitoes or gnats, but dapper brown Hackberry Emperor butterflies.
The Hackberry Emperor and its relative, the Tawny Emperor, are found across the eastern and central United States . The Hackberry Emperor additionally occurs in the southwestern United States . The two species have a similar pattern of spotted brown wings, but the Hackberry has dark eyespots on the forewings that the Tawny lacks. It also has white spots on the forewings that are usually cream-colored in Tawny.
Emperors are noted for their “tameness”. They will land on people and probe with their tongues on skin and clothing. They don’t bite; all they seek is moisture and salt from your sweat. I have had the butterflies land on me many times and it’s always delightful to have them as a temporary ornament.
In late summer and fall, emperors always seem more common here, but this year I think there are more than usual. My neighbors in Greenwood , Frank and Karen Williamson, had a whole tree covered with the butterflies one weekend. Many trees in the woods have a nice complement of butterflies, too.
The emperors don’t harm the trees; they are just perching and basking in the sun. They like to eat sap, so if the tree is oozing sap they will stop for a drink. Other foods that emperor butterflies consume are rotting fruit, dung, and carrion. Sometimes they will also sample flower nectar and mud. The caterpillars of both species eat leaves of hackberry trees.
Many other butterflies and moths also have caterpillars that like to eat hackberry leaves. The American Snout is one of my favorites. It has a long snout (not actually a “nose” in our sense, but the labial palps of the insect) that it places along a branch, imitating the base of a leaf. Combine that with its dead-leaf wing coloration and it has a pretty handy disguise.
Down in south Texas they are having a major snout migration, on the order of millions upon millions of snouts. I read on Mike Quinn’s Texas Entomology website (http://texasento.net/snout.htm) that this massive population increase is caused by drought (reducing parasitoid populations that would otherwise parasitize the caterpillars) followed by rains that cause tender new growth on the hackberries, presenting an all-you-can-eat buffet for the snout cats.
Other Lepidoptera families that have hackberry-chomping members include Limacodidae (slug caterpillar moths), Notodontidae (prominents), Noctuidae (owlets), and Lymantriidae (tussock caterpillar moths). The snout and the emperors are in the Nymphalidae family (brush-footed butterflies), but are in different subfamilies. This group is called brush-footed because the front legs are reduced in size compared to other butterflies.
Keep your eyes open for nature’s wonders the next time you walk by a hackberry tree, the potential home of snouts, emperors, their caterpillars, and more. You never know.