January 2020

Why so pale?

I was wondering what this spider was? It had been building a web in my toilet.


An immature female Redback Spider. Image courtesy of Richard Todd. A mature female, showing characteristic colouration. Photo by Jeff Wright.

The spider in your image is a juvenile female Redback Spider (Latrodectus hasseltii,) so it seems appropriate, given the traditional Australian anecdotes, that you would find it in your toilet.

We are used to seeing images of the black bulbous abdomen and the bright red stripe of the adult Redback Spider, but we less commonly see the juvenile spiders with this pale abdomen and brownish tinged strip. These immature female Redbacks are commonly mistaken for males, which are much smaller and are rarely seen.

The characteristically tangled web of Redbacks is an effective trap for prey, including insects, other spiders, and even small vertebrates. This tangled mass of silken threads also serves as a retreat for the spider, and a nursery for its eggs. However, the web is not a fortress; some other spiders, such as Daddy-long-legs and White-tailed Spiders, will enter the web to prey upon the Redback within.

Redbacks have a notorious reputation for their potentially fatal bite. Their tendency to build webs in warm sunny areas like barbecues, under outdoor furniture, garden sheds, and water tanks means that they frequently come in contact with humans.

Only the female Redbacks are known to bite and reactions to the bite can be highly variable. The Redback is able to control how much venom it injects, and some bites are “dry’ bites, used in defence only.

Want to know more? Our Discovery Centre is a free service open seven days per week, with experts ready to answer your questions. You can phone, write, contact us via our website or pop in. If we don’t know the answer we will try to find out for you.

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