gardenersassistant's picture

Spider at Portbury Wharf

Observed: 23rd September 2011 By: gardenersassistantgardenersassistant’s reputation in Invertebratesgardenersassistant’s reputation in Invertebratesgardenersassistant’s reputation in Invertebrates
0406 11 2011_09_23 P1180041 PS1 CrBuLetDf7x30ExCuCu900hSS39x0.3
Description:
Identifications
Species interactions

No interactions present.

Comments

simon Ran's picture

Tetragnathid

I think this can be narrowed down to the Genus: Meta. I have used the information given by Michael Roberts in 'Collins Field Guide to Spiders' to suggest the following:

There are 5 species of Meta in Britain, two of which occur only in totally dark habitats such as caves - so they can be ruled out here. This leaves three species - M.segmentata, M. mengei and M.merianae. The latter species is found in damp, shaded sites e.g. overhanging vegetation by streams and ditches and under bridges. However,the photo sugests a more open habitat. Thus it narrows down to either segmentata or mengei, both of which are "probably the most common orb -weaving spiders in northern Europe". However to separate them is not easy. Females' epigynes have to be examined under a microscope. Males are a bit easier, as a lens is sufficient to determine whether there are ventral hairs on metatarsus and tarsus 1 or not.If this is a male however,the photo's definition isn't good enough to see this feature.

The only other way to help decide which of the two species it is, is by looking at their maturity period. Assuming this one is a mature individual, then M. segmentata seems the best bet, having a mature time span from late summer to late autumn, whereas M. mengei is around as a mature adult from spring to early summer.

So, by a process of elimination, it is probably Meta segmentata.

Alan Thornhill's picture

Agreed

I agree with the above but the Meta genus has been split in to two genera - Meta and Metellina. The species you mention as possibilities, inc. segmentata, are in Metellina