Hot stuff

Posted by Graeme Lyons , Thursday 16 January 2020 21:50

This story ends with a spider in a butterfly house in a zoo and starts with a phone call a week earlier about pan-species listing. There is a thrush in the middle.

On Monday I went up to see Mark Telfer about buying a microscope off him after discovering quite by chance he was selling one. No point driving 100 miles to see an old friend without some natural history though, so we were soon heading over to Whipsnade Zoo. A month after the Black-throated Thrush was first seen there. I like to think of this as 'danger twitching', waiting as long as you possibly can before going for the bird. It was an effortless twitch and I took this absolutely stunning photo. My first new British bird since the Elegant Tern in 2016. This is a really awesome bird and deserves more than this but this just isn't his story.

Then we went into the butterfly house. Now I have done very little in hothouses, my only attempt was at the BMIG excursion to Wisley Garden Centre. I was a little bewildered by how many species Mark was finding, such as these impressive molluscs which Mark identified as Subulina octona. My completely steamed up camera and hand lens were making me feel out of my depth.

The spiders seemed a bit more do-able. A single large Ulobrous plumipes and dozens of Achaearanea tepidariorum (with some adults of both sexes) were present along with a few familiar Pholcus phalangiodes. Mark picked up a couple of little orange things that looked very like Oonops which I suggested they were. I couldn't find one beyond a very small immature. Then I noticed something scrambling around in the leaf litter. Possibly a parasitic wasp, I just about got it into a tube to see it was a tiny ant mimic type thing that was clearly an adult male. I vaguely remembered there being something of this shape in the new book and a quick look through and I thought I wouldn't be far off calling this Coleosoma floridanum.

I was very excited to get home and see it hadn't been seen since 2005. What a strange beast, hard to believe it's a theridiid. This animal was just over 2 mm long. It has a strange peg on the underside of the abdomen, two serrated projections at the front of the abdomen, a strange cleft in the top and two undulations underneath. 


Yet the fun didn't stop there, turns out the Oonops type things were not one of our two Oonops. Mark thinks it could possibly be Triaeris stenaspis. The really odd looking abdomen and long patella of the first leg would add up. It's turned up in hothouses in Europe and apparently at some point in the UK. Thanks to Mark for this research, image and an awesome day! I do think it would be great if the SRS had distribution maps for all spiders that are surviving in places like this in the UK. They might not be able to survive outside but they are very much breeding here and not under anyone's control (i.e. they are not pets). Are they really any different to Uloborus plumipes? I can see the appeal now and I think I will be doing some more hothouses soon!

EDITS: A second update from Mark: "T. stenaspis was recorded from the Eden Project by Snazell, R. and Smithers, P. and published in Bull BAS in 2007, referring to sampling carried out between 2002 and 2004". My previous edit that this was only the 2nd UK record since 1909 is now known to be incorrect. 

Which leaves one question: Hypothetically speaking, if one was year-listing spiders, would this species count on one's list? Hypothetically speaking obviously.
(One is on 38 species).

3 Response to "Hot stuff"

Gibster Says:

Hypothetically speaking, I'd be inclined to say hell yeah it counts. Purely hypothetically, obviously.....

Mark G. Telfer Says:

An update on Triaeris: T. stenaspis was recorded from the Eden Project by Snazell, R. and Smithers, P. and published in Bull BAS in 2007, referring to sampling carried out between 2002 and 2004.

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