More angst for arachnophobes

Although Ruan Pool is pretty well dry, some of the our other pools look suitable enough for waders, yet they're in distinctly short supply so far this autumn. Stithians Reservoir is having a sandpiper-fest, so I can only presume that Simon, the warden up there, is playing dirty and has set up some kind of feeding station for waders. Well Simon, we have a secret weapon that will be kicking in soon and I am strongly tipping Windmill to turn up an American or two before September is out.

So this morning our thoughts turned to butterflies, dragonflies, moths - and spiders again, especially as the overnight mist had left thousands of webs glistening in the sunshine. We found a number of large orb webs very similar to that spun by our resident Wasp Spider (see posts below), but the inhabitants, although quite large and colourful, didn't have quite the same impact as the stunningly scary Argiope bruennichi.

We took a number of photos and were later able to i.d. them as two common species of Araneus, namely quadratus (above) and diadematus (below). Thanks to Dougy Wright for the top left and bottom right photos and supplying his shorts for the backdrop to that at top right.

Feeding-time for the beast

I renewed my acquaintance with the Wasp Spider today. The hayfield will be mown soon so I cordoned off the area where it lives. As I approached it I disturbed a grasshopper which jumped straight into its web. Now that's unlucky. It was immediately set upon. They quickly immobilise their prey by wrapping it in silk. It is then bitten and injected with venom and a protein dissolving enzyme. Nice.

This spider is listed in the Cornwall Red Data Book. Rosemary Parslow tells me that they found two in a field on Scilly three years ago. It's amazing how they spread.

An exciting discovery with a sad twist

I came across the most incredible spider at the farm this morning. The abdomen was about 1.5 cms long and from the tip of the front legs to the tip of the back legs was about 5.5 cms. That is some BIG spider! I was able to identify it from the Collins Field Guide to Spiders as Argiope bruennichi, known as the Wasp Spider. It's a female, full of eggs. That zig-zag ribbon of silk is called the stabilimentum - there are several theories as to its purpose.

In Europe this species is locally distributed in France, Germany and the Low Countries. Following the first British record in 1922, it is apparently now well established in locations near the English south coast and is spreading northwards. The females make their webs in long grass, often near field edges, and that's just where this one was.

An internet search for "Cornwall spiders" led me to www.stevehopkin.co.uk, a real enthusiast's resource where you can download a distribution map for every species found in the county. The map for the Wasp Spider shows only seven locations where it has been recorded, the nearest being on the Fal estuary. Coverage throughout the county is patchy but the Lizard and West Penwith have received more attention than most other areas.

I noticed that the maps haven't been updated since April 2006. Another search and I was shocked to learn the reason why. Steve Hopkin was killed in a road accident the following month. He had been a senior lecturer in zoology at Reading University, a scientific associate in entomology at the Natural History Museum in London and was the spider recorder for Cornwall. What is especially poignant is that the biography on his website is still in the present tense. A work in progress was abruptly and tragically terminated.

Hoverflies

I've noticed that several of my fellow bloggers have been publishing photos of invertebrates recently, so not to be out out-done, here are a few hoverflies from the farm.

Clockwise from top left:

Helophilus trivittatus

Helophilus trivittatus

Helophilus pendulus

Syrphus ribesii

Scaeva pyrastri

Leucozona glaucia

"British Hoverflies" by Stubbs and Falk is one of my favourite natural history books. All of these shots were taken with my dawn-of-the-digital-age Nikon Coolpix 4500, which I originally bought for digi-scoping, a really exasperating activity which I wouldn't recommend to my worst enemy.

Cattle diss the warden

I was down at the farm the other day and came across a huge group of people - well, at least 30 - wandering around with butterfly nets and pooters and magnifying glasses and the like. Turns out they were the Ecology and Conservation Studies Society from Birkbeck College, London, on a week's field trip and jolly. I introduced myself and was immediately surrounded (I hesitate to say mobbed) and bombarded with questions, some of which I was able to answer, such as:

"How do you manage your hay-fields?"

"When does the Cornish Heath flower?"

"Where's the nearest pasty shop?"

"What's the capital of Azerbaijan?"


The leader of the group told me that when he had walked into the first field he had been delighted to see a specimen of Parentucellia viscosa. "Yellow Bartsia!" he explained, on noting my blank expression. He then went on to say he had been completely astonished to find the next field, and the next, and the next, absolutely full of the stuff. This is an uncommon plant and he had never seen anything like it in his life. So I was able to brag about it, quite a lot.




Resuming my walk round I was struck by the numbers of young birds around: Willow Warblers, Whitethroats and especially Goldfinches. It seems to have been a great breeding season so far.

I ran the moth-trap again on Wednesday night and it produced 242 moths of 51 species. You can add to this a few escapees, a couple of micro-moths who will have to remain unidentified and a full English breakfast for the Sedge Warblers who live in the adjacent bushes and picked up many of the moths unlucky enough to have parked up in nearby vegetation. These numbers are an improvement on the last couple of summers but I reckon they are still down on five years ago. The most numerous species in the trap was surprisingly Elephant Hawk-moth, with 32 individuals. Here are some of the squadron waiting for the signal to scramble.





And here's a Plain Golden Y, a beautiful moth, though not quite as beautiful as the Beautiful Golden Y!






Yesterday I found a group of cattle which had managed to infiltrate the meadows which are kept for hay, via a broken electric fence-wire. They were clearly having a wonderful time chewing on the succulent long grasses. I went over and and made an attempt to herd them back out on to the pasture. No way were they going to agree to this. They just went round in a circle and settled back down where they started. I tried to appeal to their better judgement:

"This is your winter feed. If you eat it now you might regret it later." I said.

Here is their spokescow, mouthing "We're staying put, so get lost!"

I left them to it and phoned James, the farmer. It's his problem, not mine!