Swarms – hundreds – thousands? – of Hackberry Emperor butterflies have graced our part of Clayton County the past few days. The tiny, 2-inch creatures, speckled with brown, white, and black, dot the gravel road, flit around the yard, and sip on the juice from moldy grapes in the compost pile.
Unlike many butterflies, the seldom nectar on flowers. On the gravel road, they apparently find minerals they need. Instead, they might perch on your skin to feast on traces of salt in your sweat. And – yuck – a favorite hackberry buffet is feeding on who-knows-what in bird droppings and animal feces.
There’s been an irruption of Hackberry Emperor butterflies – named for the hackberry tree leaves that their caterpillars feed on. Why the proliferation? Why now? Entomologists can’t say for sure. A mild winter may have allowed more of last year’s caterpillars to survive in the hackberry leaf litter on the ground. Then these larvae crawled back up to their favorite hackberry trees to munch on leaves, even defoliating some branches.
Fat and ready to metamorphose, the caterpillars formed pupas (chrysalises) on handy surfaces. Our neighbor found dozens on the paddleboards in a trailer near the Turkey River. The green, inch-long pupas also were attached under the eaves of a wooden shed, under a picnic table, and underneath hackberry leaves.
When they emerge, the adults will lay a cluster of eggs, then die after a few days. But their caterpillar offspring will hatch and start munching hackberry leaves again.
Later in the summer, instead of forming a pupa, the caterpillars will burrow into leaf litter to over-winter. If they find a cozy spot, we may see another spectacle next spring.
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Fascinating. The wonder of life.
Thanks for the information! I was on the Wapsi Friday and there were thousands of these butterflies on the sandbars. Before I could look them up I read your article and there was the answer.