This species has been marked as a ‘Most Likely Species’ on our Garden species list as despite the excellent guide Britain’s Spiders 1* suggesting there are no similar species if the characteristic features can be identified, on referral to the Facebook Spider ID group there was some question as to whether this could be Parasteatoda tepidariorum.
We have gone with C. blattea because the specimen we examined had a dark brown/black carapace (not a medium to light brown one found in P. tepidariorum). We also felt we could see the tubercle about half way across the abdomen which characterises C. blattea, see image below. HOWEVER we have been warned that due to the specimen being dehydrated we shouldn’t place to much confidence in such features.
Note: anyone wishing to find help identifying a spider species couldn’t ask for a better group than the facebook ID group.
We did manage to film it a bit as well, the clearest video being towards the end of the clip linked below.
So this species, which marks the 550th recorded in the Garden, is added with a degree of uncertainty. It may well turn out to be P. tepidariorum. If this is Crytachaea blattea, ref 1* suggests this species was only recorded for the first time in Great Britain in 2015. Whilst extremely rare at present it does appear to be spreading with several records dotted about, especially in South Wales and the Southwest of England. Wikipedia suggests it is native to Africa but has been introduced to much of the world, including Europe.
Whatever this little critter is we let it go where we found it and hope it enjoys its time in the Garden.
DC: 29/05/2023
1* Bee, L & Oxford G & Smith H. (2020) Britain’s Spiders: A field Guide. Second edition. Oxfordshire: Princeton University Press
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