Spider beetles

Definition

A subfamily of small, oval beetles (Ptininae, family Ptinidae) characterized by long legs, a humped thorax, and a superficial resemblance to spiders in both posture and movement. The approximately 600 species are primarily scavengers and stored-product pests, feeding on dried organic matter including grain, dead insects, wool, and museum specimens.

Etymology

From the spider-like appearance: long legs, rounded body, and habit of raising the forelegs when disturbed.

Example

The Australian spider beetle (Ptinus ocellus) and the American spider beetle (Mezium americanum) are common pests in food warehouses and herbarium collections, where they chew holes in dried plant specimens and packaging.

Synonyms

• Ptininae

Related Terms

• Ptinidae
• stored-product pests
• dermestid beetles
• bostrichid beetles
• museum pests
• scavenger beetles
• humpbacked appearance
• anobiid beetles

Usage Notes

The common name refers to morphology, not phylogeny; spider beetles are beetles (Coleoptera), not arachnids. The subfamily Ptininae has undergone recent taxonomic revision, with some authorities formerly placing these beetles in Anobiidae. Identification relies on the globose body, long filiform antennae, and coxae that are widely separated (unlike anobiids).