Meta menardi

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European cave spider
Scientific classification
Kingdom: Animalia Phylum: Arthropoda Class: Arachnida Order: Araneae Family: Tetragnathidae Genus: Meta Species: M. menardi
Binomial name
Meta menardi (Latreille, 1804)

The European cave spider, Meta menardi, is a long-jawed orb-weaving spider (Tetragnathidae)^[1] it is also known as the Orbweaving cave spider, the Cave orbweaver and simply the Cave spider (in context). It is a large, reddish brown spider with a natural range extending from Scandinavia to North Africa and from Europe to Korea, there are also transplanted populations as far apart as Japan and Madagascar. They are one of the largest spiders found in the United Kingdom with adults reaching roughly 5 cm legspan and 15 mm body length, only the raft spider is bigger. It is widespread and locally abundant^[2], although rarely noticed due to its habits. They are neither endangered nor protected^[3] in the UK.

The adult spiders are photophobic and live in places free from light, frequently in caves and tunnels, they are most often observed in railway tunnels and mines since these are more likely to be visited by humans. The young spiders are, in contrast, strongly attracted to light^[4] — probably an evolutionary adaptation which ensures the spread of the species to new areas.

Egg sacs are tear shaped white pendants (sometimes with a slightly yellow centre) usually hanging from the roof of the habitat by a silk thread approximately 20 mm long.

Meta menardi is extremely difficult to distinguish from Meta bourneti, to the extent that differentiation requires a microscope and considerable expertise. Meta bourneti has similar range and habits to Meta menardi and non arachnologists rarely bother with the distinction referring to both species by the same common name.

Cave spiders feed on smaller invertebrates, most frequently myriapods and slugs ^[5].

The European cave spider is not dangerous and although (in common with nearly all spiders) they have venom, its effect on large mammals is negligible. They are unlikely to bite if carefully handled but if sufficiently provoked they are capable of inflicting an unpleasant "nip". They are non-aggressive and generally slow moving and are regarded (by arachnophiles) as "gentle giants".

A media frenzy was caused when British Telecom engineers working in the grounds of Windsor Castle discovered a colony living in conduits and manholes. These were incorrectly described as swarms of aggressive spiders, up to 10 cm in size (a classic arachnophobic size estimate). The error was compounded when they were identified as a new and probably highly venomous species by Graham Smith, a misinformed entomologist ^[6]. The initial incident was widely reported but when the species was properly identified the matter received little publicity.

Cave spiders can be seen at Chislehurst Caves if you know where to look (ask your guide when going on a tour).

[edit] External links

Further Pictures of Meta menardi at Nick's Spiders

[edit] References

1. ^ Locket, Millidge & Merrett, British Spiders vol III, 1974, ISBN-13: 978-0903874021
2. ^ National Biodiversity Network, http://www.searchnbn.net/gridMap/gridMap.jsp?allDs=1&srchSpKey=NBNSYS0000008929
3. ^ UK Joint Nature Conservation Committee, http://www.jncc.gov.uk/page-1815
4. ^ Smithers P, Bulletin of the British Arachnological Society, 2005, Vol 13; Part 6 Pages 213-216
5. ^ Peter Smithers, Journal of Arachnology, August 2005
6. ^ BBC News, http://news.bbc.co.uk/2/hi/uk_news/1396706.stm, 19 June 2001