T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


False widow spider (Steatoda bipunctata)

Kingdom: Animalia
Phylum: Arthropoda
Class: Arachnida
Order: Araneae
Family: Theridiidae
Genus: Steatoda
Species: S. bipunctata
Binomial name: Steatoda bipunctata
Common name: Common False-Widow, Rabbit hutch spider

Steatoda bipunctata is a species of cob-web spider common in North America and Europe. It may be found in proximity to human structures, such as basements, sheds, garages, fence panels, beneath windowsills and occasionally indoors in cooler parts of the home.
The web is a three-dimensional tangle of threads, which are characteristic for this group of spiders.
Since Steatoda bipunctata looks similar to the Black Widow spiders of the genus Latrodectus, they are commonly called 'False Widows'.
The dark and shiny abdomens of both sexes are bulbous.  There is a distinctive very pale dotted band running around the front edge of the abdomen. Some abdomens can be patterned, with a white stripe down the centre. The upper surface of the abdomen has two distinctive pits (punctata) that are usually clearly visible. The cephalothorax is a dark brown. The spiders body rarely exceeds 7mm in length for mature females and 5mm for males. The legs have a maximum span of 15mm.
This is an entirely harmless species as there are no known instances of envenomation because fangs of this species cannot penetrate human skin.

Photographed at New Plymouth, Taranaki.