Bianca, the bowl spider
Also known as double-tailed tent spider, Calamvale bowl spider
Good morning. Isn't this a wonderful day to catch a fly!
I'm Bianca the bowl spider. I build my web in the shape of a bowl, and strengthen and camouflage it with leaves. I like to build my home on the ends of thin overhanging branches, and I use the leaves and twigs at the end of the branch to build into my web. Some bowl spiders construct a web more like an upside-down tent, because we are related to tent-web spiders. But most of us at Calamvale Creek build them like a bowl.
You can see from the photo above how well I blend in with my surroundings of variously coloured dry leaves, twigs, and bark bits.
Meaning of my name
My scientific species name is Cyrtophora exanthematica. The first part, cyrto, comes from a Greek word that means “curved”. The second part, phora, means “bearer”. So my name means “curve bearer”.
My species is also found in Singapore, India, Papua New Guinea, Indonesia, Myanmar, Japan, and possibly other warm countries. In Singapore I am known as a double-tailed tent spider, because of the two projections at the posterior end of my abdomen.
Am I dangerous?
I'm not an aggressive spider, so I am unlikely to bite you unless you try to pick me up. My bite may make you feel uncomfortable, but I'm really interested only in insects.
I put a lot of planning into my web, because it's not easy building a bowl out of web strands and leaves.
Our webs at first look like a masterpiece of architecture, but they become untidy after a while as they pick up dirt and tree pieces that fall into them.
I chose to build my home about 160 centimetres (5 feet 4 inches) above the ground, at the end of an overhanging branch. Other bowl spiders build their homes a little higher or lower, and people occasionally walk into the lower webs or accidentally knock them, without realizing a spider is inside.
Many people don't notice our webs, because the silk is not obvious and the leaves look like they are part of the tree (which they are most of the time). I build with more green leaves occasionally to continue the camouflage.
The shady paperbark trees around Calamvale Creek are a perfect environment for me. In fact there are dozens of our webs around the creek, although you may never see us unless you know what to look for.
My egg sac
When I produce my white oval egg sac, I lie face down on it with my legs outstretched (see photo at right, taken at sunset). It's a good way to look after the kids while I wait for a meal to drop in.
Quite a number of bowl spiders have made their homes around Calamvale Creek. If you find one of us, there will be others not far away.
— Bianca the bowl spider