Tuesday, 23 September 2008

Gum-footed Tangle-web Spiders

.....family Theridiidae

The spider family Theridiidae gets it's common name from the structure of the webs. An apparent chaotic tangle, the web is in fact an ingenious trap consisting of vertically stretched threads that are attached to the ground with globs of gum. When the potential prey walks into one of the threads, it retracts and the prey is flung into more threads, thus immobilising it. . This family includes one of the most infamous of Australian spiders, the Redback, Latrodectus hasselti. However the spiders below belong to the closely related genus, Steatoda.

These tend to be smaller that the Redback but you will notice some similarity in form. Some even exhibit a small red spot. These are extremely common in my backyard and can be found under just about any rock (and believe me, as a vegetable gardener, when I tell you I have a lot of rocks here). I have even found them a good 600mm below the surface in a small cavity under a rock.

It is said a bite can induce headache and nausea but bites are not common due to the small size of the fangs.


(Click on Photos to Enlarge)

Steatoda.sp - This one found at least 600mm underground



Steatoda.sp - female with egg sac under a rock


4 comments:

  1. We've got plenty of redbacks Mosura, but I don't think I've seen these spiders. Very similar to the redback, I'll have to look more closely.

    ReplyDelete
  2. Thanks Duncan - When I first moved back here they had me confused (especially the ones with red on them). There are definitely some Steatoda spp in Vic.

    ReplyDelete
  3. Redbacks and these black/brown ones (or similar) were common in Canberra. None here in Robertson - presumably too wet for them. Lots of other spiders, though.
    Nice shot with web.
    Cheers
    Denis

    ReplyDelete
  4. I've seen them here, Mosura. (Pre-digital camera.)

    I also have heaps of rocks. The next decent day I might have to go on 'a mission' :-)

    ReplyDelete