This tiny little spider is one of the most interesting species that I've found around where I live. They are documented on the Spider Recording Scheme as mainly being found around the Thames Valley, Essex and Berkshire and Surrey. They are also found in the Severn valley in Gloucestershire, Worcestershire and Warwickshire. Recently they have started turning up here in Burton-upon-Trent!
Given the locations that they commonly reside, its quite easy to assume that they made their way along the rivers, either on canal boats or by ballooning down them. Looking at their distribution and then comparing with a river map, it's definitely feasible that this is how they have spread themselves.
These spiders are absolutely stunning and they're incredibly tiny, growing to around just 4 or 5 mm! As their name sake and colour implies, these spiders favour green leaves and they weave a protective mesh web over the top of themselves when they find one that they like. This makes them incredibly difficult to spot and even harder to photograph!
The females are a brilliant emerald green all over whereas the males have a vibrant red head that contrasts with this! This is known as sexual dimorphism , which pretty much means the males and females are visibly different. This is common in most spiders but very visually obvious in Nigma walckenaeri.
An amazing little spider that I didn't expect to find in this location, yet alone in my garden!
Map from: http://srs.britishspiders.org.uk/portal.php/p/Summary/s/Nigma+walckenaeri
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