Saturday, February 19, 2011

Achaearanea sp. - so very good to watch

This is all about the little spider who is almost everywhere on houses around the world, and often goes unnoticed. But once you find them, they are so very good to watch, because there is nothing hidden. They are sometimes called the American house spider, or the common house spider, and are introduced into Australia.

Achaearanea species are small spiders in the Theridiid family - that is the big family which includes the black widows and redbacks. All theridiids tend to have the big abdomen and tiny cephalothorax. Achaearanea are totally harmless. (Click on images to get a bigger version).

The webs are messy cobwebs, so it usually looks like a messy, unused web, until you look closely and see the pale owner. A strong torch, even during the day, helps a lot.

The males are easy to identify - smaller than the females and with the 'boxing glove' palps typical of mature males. I have watched the mating games go on for hours, sometimes with one guy ... 

... or maybe two.

The female will build a messy egg sac, hanging it in her web.

And then they hatch. Great to watch - and the babies stay around for a week or more.

There is so much to say about these litle guys, but that will almost do for today. Except for one of their most notable acts - the ability to deal with prey much bigger than themselves.  Here one has bailed up a white-tailed spider (Lampona sp.) ...

and a massive (on small spider scale) beetle.

All you have to do to see them is leave the messy webs alone. They are everywhere!