Report from spider recorder for AGM November 2 2016
By Edward Milner
In London and Middlesex this year (November to November ) just 89 spp. were recorded, that’s only half as many as last year (166spp.), due partly to the conclusion of pitfall-trapping at Bounds Green wilderness and at Tooting Common. It seems to have been a poor year in terms of both spider diversity and numbers, but I was also less active in the field this year due to illness. I had to cancel the usual summer foray was postponed although I hope it can be rearranged as a winter foray in the next few weeks. Unsurprisingly (but unusually) there were no new county records either for the counties of London or Middlesex.
Spider forays
As LNHS recorder I led a spider foray at Coldfall Wood (for the Friends of Coldfall Wood) to encourage interest in invertebrates generally and spiders in particular, as well as publicising LNHS activities to the general public.
Trapping
Pitfall trapping has been continued at long-term sites in Mile End Park, and Tower Hamlets Cemetery, has concluded at Pinkham Way (North Circular Road) a site threatened by developers, and Tooting Common for L B of Wandsworth.
New and Interesting Records
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In the absence of new records it is worth noting that a single male Alopecosa cuneta (Lycosidae) was trapped at Kirk’s Place, Mile End Park in June, a site from which six other wolf spiders have been recorded. This scarce species is only known from three other sites in London; the upper part of Hampstead Heath, the north-east corner of Richmond Park, and Greenwich Park.
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A most unusual event was observed by local staff at Tower Hamlets Cemetery Park at the end of September. Large, well-constructed sheet-webs up to 2 m across were seen covering much of the surface of a large compost heap. Close inspection on 4th October revealed large numbers of adults of a tiny orange spider Ostearius melanopygius (Linyphiidae). The extensive webs had apparently been constructed collaboratively by these tiny money spiders. In warm conditions with very little wind (19° C at Heathrow airport) the spiders were ballooning in considerable numbers. While mass ballooning is a well-known and fairly frequent phenomenon, the construction of such spectacular webs is rarely reported.
This was the first record of O. melanopygius at the Park. It is a cosmopolitan species (Haigh, 2012) found in a very wide range of habitats, especially in urban areas, on rubbish heaps in gardens, and occasionally inside buildings (www.britishspiders.org.uk), as north as Inverness in Scotland, and around the world from New Zealand to Scandinavia. In London it was previously recorded from 7 sites, but only two sites in Middlesex. Large webs preparatory to mass ballooning like those observed at Tower Hamlets Cemetery have been reported from Mainz in Germany by Jager (2002).
References
Agnarsson,I. et al. 2006. Sociality In Theridiid Spiders: Repeated Origins Of An Evolutionary Dead End. Evolution. 60 (11): 2342-2351.
Haigh, D. 2012. Ostearius melanopygius – a cosmopolitan spider. SRS News No 73 in Newsl. Br.arachnol. Soc. 124: 13-14.
Jager, P. 2002. Aggregative Spinnennetze – weitere Funde in Deutschland und
mögliche Erklärungen. Arach. Mitt. 23:33-44
J Edward Milner 4/11/2016 Recorder for Spiders
