Birds, Leps, Observations & Generalities - the images and ramblings of Mark Skevington. Sometimes.

Monday 17 February 2020

Missing Sector

Last night I noticed another spider loitering on a ceiling, this time in the en suite. I felt compelled to pot it up and have a look. Once secured, I got the handlens on it and quickly ran though the decision-making flowchart that I carry around in my head where spiders are concerned. Essentially: is it a jumping spider - if not, it is marked/coloured - if so, is it big enough for me to study critical features. Any jumping spider is cool and automatically warrants scrutiny. Anything else simply has to be big enough or at least have some distinctive-looking feature for me to bother. Anything that is either unicolourous, or worse a properly tiny Linyphiid, then I will almost certainly ignore it.

Anyway, this spider was smallish but had easy to see markings with the handlens. With it being indoors, and me being in Leics., I decided there can't be that many options so I decided to have a quick squint through NatureSpot first. Quite quickly I noted a very similar and obvious candidate, which when compared to my Collins and WildGuides books seemed to be right: Zygiella x-notata (Missing Sector Orbweb Spider). Almost always associated with human habitation, very common and widespread.


[Note that I used the same disposible wooden spoon that has been loitering in the 'study' and is now a handy spider-wrangling implement for photography.]

There is a similar species which is normally found outdoors, Zygiella atrica, and this is equally common and widespread so I decided to check further just to be sure. Mine was a female, so I set about anaesthetising it enough to get a USB scope shot of the epigyne.


Quite pleased with that to be fair, and more importantly it seemed to match the description and illustration in Collins vs Z. atrica. Anyway, record submitted and duly accepted - nice, a new spider on my list.

Here's an eight-legged musical interlude ....


3 comments:

AJ Cann said...

Indoors it's most likely to be Z. x-notata but some recent work has shown Z. atrica is a lot more common than previously thought and I suspect many records have been missed. so I'm going ti be very strict in these from now on - e.g. show me the genitals!

Pierre Ogier's website is the place: https://arachno.piwigo.com/index?/search/150

Skev said...

Thanks for that link, great stuff - halps make sense of some of the illustrations in Collins. I intend to try and get shots of epigynes / palps for anything that needs it - how successful I am is up for debate. I'm not likely to be trying anything reallu tiny just yet though!

AJ Cann said...

Always happy to receive specimens for I.D. Happy for you to record them.