Our insect of the week for December 15, 2025 is the beetle Geotrupes balyi [COLEOPTERA: Geotrupidae]. It is commonly called Baly’s earth boring beetle. This species was described by the French entomologist Henri Jekel in 1865. He described over 550 taxa during his life and has over 60 species of beetles named after him.

Adults are most active in spring and summer and are often attracted to lights at night. They excavate burrows to lay their eggs. Larvae are detritivores and feed on dead leaves provisioned by the adults.

The specimen shown here was collected by Mark DuBois in Peoria County, Illinois in June.