Horned Passalus Missouri Department of Conservation

The horned passalus belongs to a family of beetles called Bess beetles or patent leather beetles. It’s the only species in the family that lives in Missouri. Bess beetles are black and shiny (like patent leather), and have one lengthwise groove on the pronotum (shoulderlike area between head and wing covers). There are lengthwise grooves on the wing covers, too. The antennae are not elbowed. The horned passalus has a forward-pointing horn on its head and lives in colonies, with the larvae, in well-rotted wood. Adults and larvae communicate by rasping noises, made by rubbing parts of their bodies together. They often stridulate (make the rasping sound) when picked up, overturned, or otherwise harassed. The larvae are whitish grubs that live in rotting wood. The heads are brownish, and it looks like they have two pairs of legs (the hind pair is shorter and used to make raspy sounds). They look a lot like the larvae of other beetles.

horned passalus - Odontotaenius disjunctus (Illiger)

horned passalus - Odontotaenius disjunctus (Illiger)

PDF) Bess Beetle (Coleoptera: Passalidae): Substrate Availability

Insect Identification

May Beetles (June Bugs) Missouri Department of Conservation

Springfield Plateau: October 2017

PDF) Two Divergent Genetic Lineages within the Horned Passalus

PDF) Ecology and Conservation of Passalidae

Stag Beetles (Lucanids) Missouri Department of Conservation

horned passalus - Odontotaenius disjunctus (Illiger)

Ground Beetles (Carabids) Missouri Department of Conservation

Springfield Plateau: October 2017

Ecology and Conservation of Passalidae