Tuesday, December 3, 2013

My smart little orb weaver

A new spider season. As summer starts, the webs are getting bigger, and there are lots of them. Last season there were few orb weavers around. After a wet winter this year, there are plenty. Three of the orb weavers I am checking every night are three different species. I have become extremely fond of the little spider in this blog, who I've watched grow from a speck to near her full size, a body length of about 10 mm.

Intelligentsia is a clever little spider. She built her web across the door into my Garret, the studio where I write. I have 'trained' orb weavers before - moved the main structural lines which were in the wrong place a few times, and the spider seems to get the idea. I did the same with Intelligentsia. For a month or so now, she has built her web with a curved 'doorway' for me just high enough to go in and out with ease. Unfortunately, husband Damian forgot to duck last week and ruined Intelligentsia's web. Fortunately, as he bumbled into her real estate during the day, she was safely tucked away in her retreat.
[Click on the images for full size.]

Intelligentsia has the bumps on her abdomen, front and rear, typical of her species, Eriophora pustulosa. Her underside has the black patch which also distinguishes the species. This is the view I get as I leave the Garret. 

Intelligentsia comes out each night, repairs her web (or rebuilds it if some silly man has forgotten to duck). She lives the usual active life of a spider, including catching, killing and and devouring insects.

During the day, Intelligentsia retreats to a patch of old web from a long-gone cobweb spider in a gap in the verandah roof. One leg is always in touch with her orb web, just in case dinner arrives early.

I'll introduce the other two orb weavers in the next blog. And keep you informed on Intelligentsia's life.

Monday, May 27, 2013

The final weeks of Wonderful, the garden orb weaver.

Wonderful was a garden orb weaver, Eriophora pustulosa. I told of her life in a previous post, The story until here ... She hung around on her web all summer, getting larger and fuller in the abdomen until she was very fat (for her size). Every night I photographed her. (All images enlarge if you click on them.)

Then one night she was gone. I checked throughout the night and in the morning and throughout the day. There was her retreat, silk lined and spiderless.

The next night she returned. But the huge abdomen was now very thin. Somewhere nearby there was an egg sac. I started hunting. These spiders are known to be very good at hiding the egg sac, but then again, I'm a master spider watcher. I knew I'd find it.

Each night she spun a web as usual, and usually took it down before morning. Each day I hunted for that egg sac.

She fed night and day and started to regain condition. I kept hunting.

It was a horribly dry summer, so on hot days I watered her. As soon as the light sprinkles from the hose stopped, she emerged to drink. I hunted some more.

She hung around, looking beautiful. The leaves started to fall from the bushes, but no egg sac was revealed. This photo ...

... was the last I took of her. The next morning she was gone. I couldn't find any trace of a body. And the egg sac? I'm still hunting.

Saturday, March 9, 2013

Geelong's leaf-curlers - simply stunning

We went to the Geelong Botanic Gardens on Monday was to see the pelargoniums. It was a stunningly wonderful surprise to see the giant ferns and palms decorated magnificently by the webs and retreats of lots of Australian leaf curling spiders (Phonognatha graeffei, family Araneidae). All photos were taken by Damian Kelly.

These incredible spiders weave a part orb web and then draw up a leaf to create their retreat. They choose a fresh leaf from the ground below their web site, and then haul it up. Spiders have been witnessed lugging leaves up to four times their own weight. 

When in place, they stitch and tension the leaf, the tension in the silk curling the leaf into a cylindrical retreat as it dries out. Drier leaves are harder to curl breaking easily as the spider tries to bend them.

 Research with leaf curling spiders has shown they select their leaves very carefully. Under test conditions, some decided, later in the weaving process, to remove a dry leaf to replace it with a moister, greener leaf. When a tad on the lazy side, or fortunate enough to have the opportunity, a leaf curling spider may choose to haul an empty snail shell into the web instead.

Look how beautifully she holds onto her web with her front legs.

 I suspect the smaller spider is a male approaching the female's leafy retreat.

The males cohabit in the leaf retreat with immature females, waiting for her to moult. During that vulnerable window, he mates safely. Males will also cohabit with mature females and respond agonistically to rival males. But it’s not all rosy for the male Phonognatha. Females may eat him anyway.

Oh, and while we're talking about the wonderful Geelong Botanic Gardens, here are some of their pelargoniums. The only thing I enjoy photographing more is spiders.

Tuesday, February 26, 2013

My garden orb weaver lives up to her name - Wonderful

Wonderful, a garden orb weaver (Eriophora pustulosa), is living a very active life. (See the previous blog for her introduction.) Last night, she was hanging around on her web, just as garden orb weavers should. 

Please click on the images - I'm rather proud of these!

She collected a lots of food on a hot, moist night - the first rain for months had just started dribbling. She was soon feeding on two wasps she'd bound together.

Another wasp flew into her web - she rushed down the silk and rapidly enshrouded her new prey in silk. Having injected it, she left the struggling wasp to die while ... 

 ... she returned to dinner.

The rain started. She headed under a leaf at the edge of her web.

And took up her usual resting position, one foot on her main web thread to detect any newly ensnared insect.

When the rain got heavy, she bound the leaves around her into a shelter. And there she sat out the storm.

Love this spider! She's Wonderful!

Monday, February 25, 2013

She's Wonderful - I have an orb weaver!

This summer has been horribly dry and hot. The spider numbers are woefully low as are, not surprisingly, the insects. I thought I had no orb weavers.

I had seen hints of silk of one at the end of the verandah, but had never seen her. Tonight the silk was reflecting clear - it was fresh and crossing a span of two metres. She had to be there somewhere. Trying to follow the silk, I felt something against my arm - something about the size of a mature female garden orb weaver. I moved away immediately, hoping that I hadn't hurt her web. And I found her!

She's Wonderful! The two protrusions on her 'shoulders' and then more on the end of her abdomen tell me that she's an Eriophora pustulosa. She had dashed over to the edge of her silk line, attached to which was only the remains of what had been a full orb. She'd clearly caught prey earlier in the evening.

I couldn't get a good photo without disturbing Wonderful, so you'll have to make do with bum-shots. She's repairing her web - you can see the globules of glue in one silk. She wouldn't come out of the protection of the leaves while I was there.

I have been negligent about blogging - I've been preoccupied with completing my PhD thesis (not about spiders) and then redrafting it for publication as a book. But that is done and my spiders can take priority again. There are so many fewer this year than usual, but of course there are the daddy long-legs (Pholcus phalangioides).

And I always have my favourites, the blackhouse spiders (Badumna insignis). They've been breeding with gusto.

Their stories will be told here. I will also include photos from those who read this blog and send me images. The Spiderblogger returns!