Nigma walckenaeri is a green, cribellate spider up to 5 millimetres long, the biggest of the family Dictynidae. While most of the body is a bit yellowish, the abdomen

Abdomen

In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...

 is a shining green, which makes it rather distinct and hard to confuse with other species. The green color makes it almost invisible. Males have an elevated head region. From August to October these spiders can be found in gardens or on walls - often on big leaves such as lilac

Lilac

Syringa is a genus of about 20–25 species of flowering woody plants in the olive family , native to woodland and scrub from southeastern Europe to eastern Asia, and widely and commonly cultivated in temperate areas elsewhere....

 or feral grapevine. The spider catches insects, sometimes larger than itself, in its web, which it builds on the surface of leaves. The female hides the 7-millimetre long egg sac on a place distant from its retreat.

In Great Britain

Great Britain

Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...

, until 1993, it was only found in London

London

London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...

 and the Home Counties

Home Counties

The home counties is a term which refers to the counties of South East England and the East of England which border London, but do not include the capital city itself...

. It may originally have been imported into Kew Gardens.http://nbn.nhm.ac.uk/nhm/bin/nbntaxa.dll/taxon_details?taxon_key=NBNSYS0000008620