A recent introduction to Europe and the UK, this species is, thanks to it's huge size, almost unmistakable. It's origins are unknown and it has yet to be determined to species which is why it is know as 'Leiobunum species A'. Apart from the huge leg span, the most remarkable feature is the dark greenish metalic sheen of the dorsal surface - particularly in the male.
There is the sexual dimorphism typical of other Leiobunum species in terms of body shape and saddle - the female being longer than the male with a more discernible saddle which can have metallic golden patches. This species also has the typical light and dark patterned coxae of the other Leiobunum species although the lighter patches tend to be more orangey. The occularium is almost entirely black - sometimes with a lighter midline (similar to L. rotundum).
Only known from a few locations in Britain - though the number is increasing all the time - notably around the Sheffield area and in South Wales. As yet, there is no distribution map for this species on the website of the Spider and Harvestman Recording Scheme.
Markedly synanthropic and typically associated with brown-field or post-industrial sites in the UK. This may reflect a preference, in their natural habitat (wherever that is) for dry rocky sites. They frequently aggregate in large numbers on the walls of buildings and other structures.
Adults are usually found from late summer to Autumn in the UK.
Hillyard, P. D., & Sankey, J. H. P. 2005. Synopses of the British Fauna (New Series) No. 4: Harvestmen. Field Studies Council, Shrewsbury.
Richards, P. 2010. Guide to Harvestmen of the British Isles. Field Studies Council, Shrewsbury.
Richards, P. 2017. Tabular key for Identification of British Harvestmen (Opiliones). Unpublished.
Wijnhoven, H. 2009. De Nederlandse hooiwagens (Opiliones). Nederlandse Entomologische Vereniging.