Diagnostic characters
- Glossy, often iridescent or two-toned body
- Constricted waist or abdominal banding producing an ant-like outline in Castianeira
- Walks with the first pair of legs raised and waving
- Conical, closely spaced spinnerets
- Rapid, jerky, stop-start locomotion
Habitat and seasonality
Leaf litter, under bark and stones, in mulch and low vegetation; occasionally wandering indoors at ground level.
Adults present late spring through autumn.
Medical significance
Low. Bites are rare and produce transient local pain only.
Myrmecomorphy
Ant mimicry in Corinnidae is chiefly Batesian: the spider gains protection from visually hunting predators that avoid ants because of formic acid defenses and aggressive colony response. The mimicry is behavioral as much as morphological, relying on the raised foreleg gait and the erratic, sustained motion characteristic of foraging ants.
Families most often confused with Corinnidae
| Family | How to separate it |
|---|---|
| Gnaphosidae | Ground spiders have long cylindrical, widely separated anterior spinnerets |
| Salticidae | Ant-mimicking jumping spiders in Myrmarachne-like genera have two large forward-facing eyes |
| Formicidae (ants) | Ants are insects with six legs, elbowed antennae, and a distinct petiole |
References
- [1]World Spider Catalog, version 26 - Natural History Museum Bern. Accessed 2026-06-14.
- [2]Spiders of North America: An Identification Manual, 2nd ed. - American Arachnological Society. Accessed 2026-06-14.
- [3]Common Spiders of North America - University of California Press. Accessed 2026-06-14.