Survey for one rare spider on NW mosses turns up four even rarer arachnids

The Nationally Rare and Near Threatened Sphagnum bog jumping spider, Sitticus floricola has been the subject of a Tanyptera Project commissioned survey to better understand its current status and distribution in a UK stronghold, the Cheshire mosses of Delamere Forest and Wybunbury Moss. Our surveyor, arachnologist Richard Gallon, used a vacuum sampler over low vegetation to successfully detect mainly juvenile specimens of the species at number of sites where it’s previously been recorded as well as new sites.

Female Gnaphosa nigerrima from Wybunbury Moss. – first ever live UK specimen

Richard was asked to record all other arachnids picked up in his suction sampler during the survey to give a more complete picture of this under recorded group on the scarce bog habitat. Not all samples have been processed yet but early findings have been enormously exciting. 

At Wybunbury Moss, the first ever female of the extremely rare ground spider Ghaphosa nigerrima (and first ever live specimen) was found at the only UK site for this species. The last record of G. nigerrima came from a pitfall trap sample in 1999, when males were identified by World Museum’s Chris Felton. It was first discovered in 1994 by the same method and recorder.

Just over the border into Shropshire, the Nationally Rare and Vulnerable money spider Carortia limnaea was re-found at one of just two known UK sites, Fenn’s, Whixall and Bettisfield Mosses NNR which straddles the England –Wales border. Our surveyor later described the small Bettisfield Moss section as one of the best arachnid sites he’d ever encountered in terms of rarity per unit area when three more Nationally Rare species turned up there. These were the third UK sites and new regional records for Minicia marginella, a ‘Vulnerable’ money spider and the Bog Chelifer Microbisium brevifemoratum (confirmed from a single specimen verified by Pseudoscorpion National Recorder Gerald Legg), as well as good numbers of the declining and Vulnerable UKBAP money spider Glyphesis cottonae. The surveyor’s report will provide vital baseline data for Sitticus floricola at all of it’s North West England sites as well as highlighting these other important records. All of our commissioned survey reports will be made freely available on this website to guide conservation management and further study.