Unusual Summer Insects

Observations of several unusual insects have prompted Missourians to contact me recently for identification help. One is the spectacular, large caterpillar of the regal or royal walnut moth (Citheronia regalis). This colorful, horned caterpillar has the common name of “hickory horned devil.” It feeds on several species of shrubs and trees, including black walnuts, butternuts, sumac and persimmon. More common in the Ozarks and eastern Missouri, it can also be found occasionally in other state locations. Although not particularly rare here, many Missourians’ first reaction to seeing the larvae is that they’ve never seen anything like it before. The pupae of this moth are found in leaf litter or shallow soil, where they overwinter to develop into adults the next spring or summer.

Another somewhat unusual insect is the hummingbird clearwing moth (Hemaris thysbe). This moth hovers around flowers like a hummingbird and has clear areas on its wing and black and yellow markings that make it look more like a bee or wasp. One observer described its body shape as similar to a crayfish. It uses its long tongue to probe flowers for nectar. This rather common species can be seen visiting flowers from early April into September. I think it attracts interest because people can't easily fit it into a category as bird, bee or moth.

The eastern hercules beetle (Dynastis tityus) is the largest beetle in North America, growing to over two inches long. The males have long pincer-like horns that make them even more striking. They live in mature forests, the larvae feeding on decaying logs, stumps, leaves and rotting fruit. As adults they eat tree sap and decaying fruit. Like most beetles, the adults can fly with wings that unfold from under the hard-shell wing covers on their backs. This would be one bug that might convince a motorcyclist to wear a face shield.

Caterpillar photo by Jim Kunstman at bugwood.org. Regal moth photo by Ronald F. Billings at bugwood.org