Our insect of the week for December 1, 2025 is the locust underwing, Euparthenos nubilis [LEPIDOPTERA: Erebidae]. This moth is found throughout eastern and central North America (including central Illinois). It was originally described by the German entomologist Jacob Hübner in 1823.

This species is often found in woodlands where the host tree (black locust) is common. Adults are attracted to lights at night and often feed on fermenting fruit or tree sap.

Fun fact – although the common name implies this moth is in the same genus as underwings (Catocala), it is not. Members of that genus are known for having one to three black bands on their hind wings. This species clearly has a different pattern.

The adult moth in this photo was collected by Frank Hitchell in Peoria County, Illinois.