Sunday, 11 March 2012

Meet the common false-widow spider

The Common False Widow Spider, Steatoda bipunctata, is a regular species in or on buildings and gardens. The female (pictured) is a shiny chestnut brown. It is a small spider, up to 7 mm, with two black spots on top of the abdomen which give it its specific name. It is also known as Rabbit Hutch spider. The male has a much smaller abdomen. It is unrelated to the Widow Spider and not particularly venomous. We found this female in the folds of the cover of a tarpaulin outside, but I have found this species on the dry underside of logs, waterbut covers and window frames. Mature specimens are found all year round, surrounded by a web made up of a tangle of silk threads, some of which are sticky and held under tension so that struggling insects might break them and dangle from them. Males stridulate during courtship making an audible sound using a series of ridges in the abdomen which rub against teeth to the front of the caparace. Although native from Europe, the species was introduced in North America in the early 20th century and outcompetes the closely related species S. borealis.

More information
Spider and Harvestman Recording Scheme Website.

Martin Nyffeler, C. D. Dondale, J. H. Redner (1986) Evidence for displacement of a North American spider, Steatoda borealis (Hentz), by the European species S. bipunctata (Linnaeus) (Araneae: Theridiidae). Canadian Journal of Zoology, 1986, 64(4): 867-874, 10.1139/z86-130.

3 comments:

TGIQ said...

Well, let's see if this works now:

One of my favourite passtimes in spring is to observe and photograph the many pollinators that visit our Spirea shrubs and cherry tree! The flowers attract an incredible diversity of insects. Sadly, we're still quite a few weeks away from seeing any flowers, but proper spring will arrive soon enough!

Africa Gómez said...

Hi BugGeek! I am glad you can comment now. The cherry tree is still in bud and it is amazing when it flowers, i get neck ache from watching insects. Here it feels very springy, and the long buglonging months of winter are behind us. It must be so hard in Canada!

TGIQ said...

LOL, I just noticed that I wrote this comment on the wrong post. FAIL! (It was meant for the pollinator post, sigh.) Yes, the winters can seem to drag on a bit, especially in March. This month is always a bit of a tease, with a few warm days here and there (we've had +15C the past three!), only to dump snow on us again. (Hmm, actually, April is much like that too!) I try not to get too excited until I start seeing actual blossoms - that's usually safe.