Earlier on in the year, I'd found a spider which Florin helpfully identified in the forums here as Amaurobius fenestralis/similis - http://www.nhm.ac.uk/natureplus/message/26245#26245
Two of them had sat quite content at the top of the window in the bathroom for months, keeping the fly population in check, until recently. We now have what can only be described as quite a substantial influx of these and very similar spiders which are pretty much all black (A. ferox?).
Instead of sitting at the top of the window in the bathroom, they've also managed to migrate to the livingroom and are doing things like sitting right in the the middle of the floor, hiding behind cabinets/around the shower or hiding in places in which they're coming in to close contact with us. The all-black ones in particular are rather large and are somewhat more on the aggressive side.
I'm really just wanting to check whether their mating behaviour could be causing them to suddenly go walkies and whether I should/can do anything to discourage them from taking up residence in daft places.
Indoor living is not that common with these spiders. They prefer cool damp areas normally and have quite a distinctive messy, lacey web. Could you post a macro photo of one of the 'all black' ones.
I rarely see black ones (had one living by the front door mat for a while) but I see more brown ones indoors, than any other kind of spider. They're pretty bold & often don't flee for cover when caught in the open. I relocate them, unless they stick close to cover, usually patrolling the bottom of my ground level window frames. They do seem to be a common prey item of pholcus phalangioides round these parts?
Hi Lewis & MWJB,
Thanks for replying.
I haven't seen any of the black-coloured ones since posting, sort of hoping they don't appear again as they weren't particularly happy with humans being anywhere near them. Best I can do unless they reappear is a description: they had pretty much the same shape and proportions as the A. fenestralis/similis spiders, from what I could tell were black all over (no discernable "V" markings on them like the other spiders have, bearing in mind I'm slightly short-sighted) and they were definitely larger - if I were to put an estimate on it around 15mm in body length, compared to between 6-12mm for the brown coloured ones. They were also distinctly bad tempered.
The "normal" Lace Weavers are still out in force though. We've got at least three/four in permanent residence on the bathroom window and several doing nightly walkies through the bathroom and livingroom (ended up almost standing on one last night, it was not for moving). The bathroom is both cold and damp and their webs do have the standard messy/irregular look. The livingroom however we keep a lot warmer and it's only been the past few weeks that they've managed to stray outside the bathroom; the only thing I can think of is that we've started keeping the livingroom window open at night, so they may have an entrance they didn't before.
We haven't got any Pholcus phalangioides as far as I can tell, however they made quick work of Drosophila earlier on in the year. At the weekend I'd spotted a mass exodus of woodlouse/slaters from under the skirting in the bathroom, many of which were either dead or in the process of dying. For a moment I wondered if there was something toxic in the building but as soon as I investigated one of the large Lace Weavers popped out as if to say "give me my lunch back" - it grabbed one of the slaters and promptly disappeared again.
Is there much I can do to deter them from wandering about where they are likely to get stood on or away from areas that we're likely to stick a finger near by accident? Although they're aboslutely great at dealing with flies and are causing no problem whatsoever at the top of the windows, I'm less keen on inadvertantly being bitten by one.
We (usually) have loads of common house spiders milling about the livingroom in August; one year I counted more than twenty in a single evening. Are they likely to be able to displace the Lace Weavers, or at least keep their numbers in check?
Sure, leaving the window open could be a factor. Mine seem to come in via window vents and mainly seem to congregate in a gap between the bottom of the window & the flooring.
Just for clarification/confirmation, it's the Pholcus that eat the Amaurobius (and just about any other seemingly beefy looking spiders), not the other way around.