Idiosoma subtriste
Adelaide Trapdoor Spider (Idiosoma subtriste) Identification
A South Australian four-spotted trapdoor spider, currently catalogued as Idiosoma subtriste, that can be mistaken for a funnel-web when a dark mygalomorph appears in Adelaide.
Usually local pain riskThe Adelaide trapdoor spider is a stocky ground-dwelling mygalomorph in the family Idiopidae. Current World Spider Catalog taxonomy uses Idiosoma subtriste; older Australian sources, including the Australian Faunal Directory entry, use Aganippe subtristis. The common name and old taxon remain useful search terms, but the scientific label needs that context. A brown or dark spider near a concealed soil door in South Australia may fit this species, yet close adult characters are required before turning a cautious field possibility into a species identification.
Quick identification
- Compact brown to dark mygalomorph body with downward-facing fangs
- South Australian location, especially Adelaide or the Mount Lofty context, as a range filter
- A low camouflaged soil-and-silk door or short burrow entrance
- A rounded glossy carapace and hairless abdominal sigilla may be visible in a clear view
What to check next
Use the South Australian location, whole body and an untouched burrow only as supporting clues. Do not lift a door, probe a hole or handle a wandering spider to check the fangs, spinnerets or abdominal spots.
When to seek medical help
Adelaide trapdoor spiders are not among the Australian spiders healthdirect highlights as medically dangerous, but a photo cannot safely rule out a funnel-web or mouse spider. Avoid handling. For a likely low-risk spider bite, wash the area and use a wrapped cold pack for local discomfort; seek medical care for severe or worsening symptoms. Treat any plausible funnel-web bite or unidentified big black spider bite as an emergency and call 000.
Where it is usually seen
Silk-lined soil burrows in South Australian ground habitat, including parts of urban Adelaide, remnant vegetation, scrub, woodland and suitable gardens. The resident is often hidden; a location or burrow without the spider is not a species record.