| Nigma walckenaeri (Roewer, 1951) |
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Scientific name: Nigma walckenaeri (Roewer, 1951) Common name: French name: Order: Araneae Family: Dictynidae Size: 3.5 to 4 mm for males, 4.5 to 5 mm for females. Biotope: Woodland edges, parks and gardens, shrubs, sometimes on walls, most often on large leaves (Ivy or Virginia Creeper for example). Web: Flat irregular web at the surface of leaves, forming a kind of net. Nigma walckenaeri is a cribellate spider, meaning that its web is made of some kind of woolly silk which retains preys. The web is generally located at the base of large leaves. The spider usually sits below, its green colour providing an efficient camouflage. Observation period: All year but mainly from August to October Geographic area: South-western Palaearctic. From England east to Iraq, North Africa. Missing in Ireland, Scandinavia and in the Baltic countries. |
The females' cephalothorax is pale yellowish brown to pale green, males' one, proportionally larger, is reddish brown. On both sexes it shows a few white hairs drawing some kind of a U-shape with the open side often at the front. The abdomen is pale green with white hairs forming thin stripes and being denser on the lateral sides. There is sometimes a whitish, yellow or red, central patch. Females' legs are green. Males' legs are reddish brown. You can easily tell apart the spiders of the Cucumber Green Spider family (Araniella sp) by they overall look, their larger size, their abdomen with black dots, their more brownish orange cephalothorax, etc. Nigma flavescens is a smaller size. Its abdomen is more greyish white to very pale green, or reddish, with grey veins. Its cephalothorax is dark with clearly paler edges. Nigma puella is also a smaller size. Its abdomen shows purple red patches, including one well marked central patch. |
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Does the distended abdomen of this female mean that it has just laid its eggs? |
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Upper side view. |
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I have observed this spider under its web, on the underside of a Birch leaf. The colour of the cephalothorax and legs indicates one female. |
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The body size of observed specimens is often an important information for naturalists, so I have now some graph paper in my photo bag. I am measuring here a body size of 3 mm, this is rather small for one female. Maybe this one has not yet reached its adult size ... |
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Here is one spider with its prey on a leaf with its beautiful autumn colours. |
André Bon November 2016