False widow spider lookalikes

Several spiders found around homes can be mistaken for false widows. Body shape, markings and colour can be useful clues, but the web and where the spider was found can be just as important.

Spiders commonly mistaken for false widows

Help identifying false widow spiders from similar looking spiders
False widow spiders are usually recognised by their rounded abdomen, relatively small head and glossy appearance, but identifying one from these features alone can be surprisingly difficult.

Several unrelated spiders can look similar at first glance. Colour can also vary considerably between individual spiders, while markings may become more or less obvious with age. Photographs add another difficulty because lighting, camera angle and scale can make a spider appear quite different from how it looks in person.

In Ireland and Britain, some of the spiders most likely to be confused with false widows include lace-weavers, black lace-weavers and the missing sector orb-weaver. None belongs to the false widow genus Steatoda.

The easiest way to narrow down an identification is to look at several clues together rather than relying on a single marking.

Lace-weaver

Amaurobius similis

Black lace-weaver

Amaurobius ferox

Missing sector orb weaver

Zygiella x-notata

How to tell a false widow from a lookalike

There is no single feature that reliably identifies every false widow. The appearance of Steatoda species varies with species, sex, age and individual colouring, so identification is strongest when several characteristics agree.

Large female noble false widow spider UK Ireland image

Image of a large female noble false widow spider.

Caution:

Not all false widows look alike. The noble false widow (Steatoda nobilis), cupboard spider (Steatoda grossa) and rabbit hutch spider (Steatoda bipunctata) can all be encountered in Ireland and Britain, but differ in size, colouring and markings.

When comparing a suspected false widow with another spider, pay particular attention to the following clues:

  • Abdomen: False widows typically have a rounded or bulbous abdomen, particularly adult females.
  • Surface and colour: The abdomen can appear smooth and glossy, with colours ranging from reddish-brown to very dark brown.
  • Markings: Pale cream or beige abdominal markings may be present, but their shape varies and they can become faint in mature spiders.
  • Legs: Leg colour, thickness and proportions can help distinguish lookalikes, but should not be used on their own.
  • Web: False widows construct irregular three-dimensional tangle webs, rather than the neat circular orb webs produced by orb-weavers.
  • Location: Window frames, wall crevices, sheds and other sheltered structures are typical false widow habitat, although location alone cannot confirm identification.

If you have both a photograph of the spider and its web, use both. The web can sometimes eliminate a possible identification much more quickly than small differences in abdominal markings.