Ant-loving Beetles

Pselaphinae

Classification

Phylum: Arthropoda
Subphylum: Hexapoda
Class: Insecta
Order: Coleoptera
Suborder: Polyphaga
Superfamily: Staphylinoidea
Family: Staphylinidae
Subfamily: Pselaphinae

Pronunciation

How to pronounce Pselaphinae: /sɛˈlæfɪˌni/

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

Images

Arthmius bulbifer - inat 81305883 by {{{name}}}. Used under a CC BY-SA 4.0 license.

Georgiy Jacobson - Beetles Russia and Western Europe - plate 16 by see in description. Used under a Public domain license.

Trichonyx sulcicollis (Reichenbach, 1816) by URSchmidt. Used under a CC BY-SA 4.0 license.

Trichonyx sulcicollis Jacobson by Georgiy Jacobson. Used under a Public domain license.

Morius occidens 255078026 by Chloe and Trevor Van Loon. Used under a CC BY 4.0 license.

Morius occidens 254410332 by Chloe and Trevor Van Loon. Used under a CC BY 4.0 license.

Summary

Pselaphinae is a diverse subfamily of beetles within the family Staphylinidae, known for their unique morphology and predatory behavior on small invertebrates. They are often associated with ant nests and exhibit fascinating evolutionary adaptations, particularly the Clavigeritae, which are obligate inquilines with specialized body forms.

Physical Characteristics

Small, compact beetles averaging 1.5 mm in size with elytra that are short and do not cover the first abdominal segment. The abdomen is broader than the head; most species possess clubbed antennae with 11 antennomeres and have a tarsal segmentation formula of 3-3-3, although variations are present.

Identification Tips

Look for their characteristic short elytra that expose much of the abdomen, clubbed antennae, and small size (0.5-5.5 mm, average 1.5 mm).

Habitat

Commonly found under stones, loose bark, moss, forest litter, and in ant nests. They are especially diverse in decaying leaf litter on forest floors, grass tussocks, and flood refuse.

Distribution

Global distribution with over 10,500 described species in more than 1,300 genera. 710 species in North America across 100 genera.

Diet

Predators on small invertebrates, specifically springtails (order Collembola) and oribatid mites (order Oribatida).

Conservation Status

Three obligate troglobiotic species from central Texas are federally listed as endangered: Batrisodes texanus, B. venyivi, and Texamaurops reddelli.

Ecosystem Role

Pselaphines play a role in controlling populations of small invertebrates in their ecosystems as predators.

Evolution

Originally regarded as a separate family (Pselaphidae), placed within Staphylinidae based on morphological similarities.

Similar Taxa

Batrisidae
Clavigeridae
Staphylinidae

Misconceptions

Despite their name, Pselaphines do not feed on mold; they are predators of small invertebrates.