Comb‑footed platform spiders refer to members of the family Theridiidae that build aplatform‑like three‑dimensional tangle fitted with gumfooted lines—sticky vertical threads anchored to the substrate. When insects strike these lines they are snapped up toward the platform, where the spider uses thetarsal comb on leg IV (serrated bristles) to fling adhesive silk and wrap prey. Representative genera includeParasteatoda and Steatoda.
Ecology & Biology
Foraging: platform tangle + gumfoot lines act as a trap‑and‑haul system for surface‑running insects.
Activity: mostly crepuscular–nocturnal; by day they rest in a retreat above the platform.
Reproduction: females place egg sacs within the web and guard briefly; juveniles linger near the maternal web.
Identification
Body size: typically 3–10 mm (females larger).
Key trait: a tarsal comb on the fourth leg used to fling sticky silk; abdomen often ovoid/spherical.
Colours: variable—browns, greys, blacks and pale morphs; some species show a glassy/metallic sheen.
Range & Habitat
Theridiids are cosmopolitan. Platform‑type webs occur around eaves, window frames, sheds, fences and in vegetation where wind is reduced and prey traffic is high.
People & Safety
Medical relevance: as a group‑level entry, most platform‑building theridiids are of low medical importance to people (excluding a few high‑profile exceptions not covered here).
Advice: minimise night lighting that attracts insects and remove old webs; relocate spiders gently with the cup‑and‑card method if needed.
IUCN: many species are unassessed; marked here as Not Evaluated (NE).
