Meet Orbi the Garden Spider

In the last days of the Christmas summer holidays we had a visit from Orbi, a garden orb-weaving spider who'd set up her web next to our lemon tree.  Her scientific name is Eriophora transmarina.  We watched her over a number of nights create her amazing web, which took her almost 2 hours and started in the dark about 30 minutes after sunset.

When she was done building she would sit right in the centre of her web, her red warning colours evident at the top of each leg.  Each leg would monitor a separate radial line for any trapped insect.

Here is a video from the first night we found her (after almost walking into the web when going to water the lemon tree.  By the way, if you do walk into a web, apparently the best way to get out is to stop, reverse and walk backwards the way you came.  The web should just peel away.  Good luck holding your nerve with that one!)

Snorkmaiden's iPad has a timelapse function, so we tried to capture Orbi on another night.  2 hours have been condensed into about 30 seconds!  Although you can't see the web, you might catch the end of Orbi spiraling anti-clockwise from the centre to the outside laying down non-stick silk.  She then spirals clockwise back to the centre laying out sticky thread using the first spiral as a reference.

There's a very nice animation on How Spiders Work which steps through the web-weaving process.

Thinking that it would be great to get a photo of the completed web the next morning, we went out to find it completely gone!  Well, not quite completely.  There was a single line - the bridge line - connecting our rosemary bush to the neighbour's apple tree.  We had to spray the line using Moomintroll's spray water bottle to catch it in the photo.

After some research we found out this was normal behaviour for orb weavers.  Often the web is damaged by the night's hunting, so it is taken down and rebuilt the next night.  Orbi took her webs down around an hour before dawn.  We never saw her do it (perhaps all her secretive night time activity protects her from attack by birds).  Orb weavers spend the day concealed near one end of their bridge line.  After a bit of hunting we found her hiding place, cleverly concealed at the end of an apple tree branch.  Can you spot her?

To see a spider taking down her web, have a look at A Spider Takes Down Her Web, where an American barn spider kindly waited until the sun came up to pack up for the day.  What takes around 2 hours to build can be packed up in a few minutes!

So, when you come across a spider's single bridge line in your garden, think of the spider hiding near one end of it and of the busy night ahead!