Deciphering Moths: Underwings
The genus Catocala belongs to the Lepidoptera (butterfly and moth) family Erebidae. While unknown to much of the general public they are popular with entomology enthusiasts due to their colorful hindwings (from whence they get the name Underwing). They have been favorites of collectors for over 100 years, and Gene Stratton Porter even has a chapter dedicated to Catocala amatrix and Catocala neogama in her 1914 classic, “Moths of the Limberlost”.
The forewings of Underwings Moths are cryptically maculated to blend with the tree trunks on which they frequently rest. It is thought that, when disturbed, they flash their colorful hindwings, temporarily startling predators and enabling the moths to escape. Larvae are also camouflaged to resemble the stems of plants on which they feed.
There are more than 250 described Catocala species with 113 being found in North America, the remainder residing in Eurasia. Fifty-three species have been recorded from Nebraska. Taxonomists long ago began a “tradition” of naming Underwing moths for feminine (girlfriend, betrothed, married, etc.) or sad (mournful, dejected, sad, tearful etc.) themes.
Some of these moths can be attracted to light at night or come to prepared fruit baits. Others can be found only by tapping tree trunks on which they rest. Another collection method is to shine lights on tree trunks at night when the moth’s eyes reflect the light and give away their location.
These moths have one generation a year, overwintering as eggs on their woody hostplants Hostplants for each species are typically restricted to a narrow group of closely related plants. They are often quite difficult to identify and many species exhibit multiple “forms”. Oftentimes identification is best left to experts as even the most “seasoned” enthusiasts are occasionally wrong.
That being said, the following pages list identifying characteristics (which are often confusing to the general public due to the terminology used by taxonomists). In an effort to minimize these terminology difficulties the following line drawings have been reprinted from “Sargent, T. D. 1976 Legion of the Night. The Underwing Moths, Univ. Mass. Press; Amherst; 222 pp.” to illustrate the wing regions referenced in the descriptions.
Anyone finding an Underwing Moth is encouraged to submit a photo to us at Nebraskabutterflies@gmail.com for possible identification and inclusion in our states faunal database.