Bess Beetles

Passalidae

Classification

Phylum: Arthropoda
Subphylum: Hexapoda
Class: Insecta
Order: Coleoptera
Suborder: Polyphaga
Superfamily: Scarabaeoidea
Family: Passalidae

Pronunciation

How to pronounce Passalidae: //pæsəˈlaɪdiː//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Images

Odontotaenius disjunctus by Mike Boone. Used under a CC BY-SA 2.5 license.

Odontotaenius disjunctus (676894205) by Matt Reinbold from USA. Used under a CC BY-SA 2.0 license.

Odontotaenius disjunctus P1420280a by
xpda. Used under a CC BY-SA 4.0 license.

Odontotaenius disjunctus P1420311a by
xpda. Used under a CC BY-SA 4.0 license.

Odontotaenius disjunctus sjh by No machine-readable author provided. Kugamazog~commonswiki assumed (based on copyright claims).. Used under a CC BY-SA 2.5 license.

Odontotaenius disjunctus variation sjh by No machine-readable author provided. Kugamazog~commonswiki assumed (based on copyright claims).. Used under a CC BY-SA 2.5 license.

Summary

Passalidae, commonly known as bess beetles or horned passalus beetles, exhibit a unique subsocial lifestyle with adults caring for their larvae in galleries within decaying wood. They are notable for their size, social behavior, and ability to produce acoustical signals for communication.

Physical Characteristics

Large dark beetles with characteristic body form, elongate-cylindrical shape, overall shiny black bodies, and ventral surfaces that may be covered with yellow setae. They have a narrower head than thorax and possess 10-segmented antennae with a three-segment club.

Identification Tips

Look for the distinctive size range of 30-40 mm, presence of one 'horn' on the head, and heavily striated elytra. The social behavior, including stridulatory communication, is also a notable identification feature.

Habitat

They live inside rotting logs in forests, forming galleries excavated by adults.

Distribution

The family is cosmopolitan, with most species in the tropics. In North America, species are found largely in eastern and south-central regions.

Diet

Adults and larvae feed on wood and must consume pre-digested feces of adults for nutrition.

Life Cycle

Adults care for larvae by providing pre-chewed food and assisting in the construction of pupal cases. The adults and larvae live together in social groups.

Reproduction

Females lay eggs in excavated galleries within rotting wood, and adults exhibit caregiving behavior towards the larvae.

Ecosystem Role

They play a role in wood decomposition and nutrient cycling due to their feeding habits on decaying wood.

Evolution

The oldest records of the family date back to the Cretaceous period, with certain genera showing potential ancient lineage.