Nuctenea umbratica
Encyclopedia
The Walnut Orb-Weaver Spider (Nuctenea umbratica) is a spider of the Araneidae family.
The walnut orb-weaver spider is very wide and flattened, with a leathery skin. Its color ranges from red brown and grey brown to black with a dark, yellowish to yellow-greenish leaf-like fleckled marking on its opisthosoma
, where small dents are visible. These are the onsets of muscles that flatten the abdomen.
Female N. umbratica can reach up to 15 mm in size, the males grow only up to 8 mm.
The spider hides during the day outside of buildings in wall crevices, or under loose bark. They are very common in Central Europe; females occur all year long, while males appear mostly during summer.
In the evening the spider constructs an orb-web that can be up to 70 cm in diameter. A signaling thread leads from the web to her hiding place. After dusk she sits in the web's center.
This spider is capable of biting humans, causing itchiness and a burning sensation followed by a red patch with white lumps.
Description
Opisthosoma
The opisthosoma is the posterior part of the body in some arthropods, behind the prosoma . It is a distinctive feature of the subphylum Chelicerata...
, where small dents are visible. These are the onsets of muscles that flatten the abdomen.
Female N. umbratica can reach up to 15 mm in size, the males grow only up to 8 mm.
The spider hides during the day outside of buildings in wall crevices, or under loose bark. They are very common in Central Europe; females occur all year long, while males appear mostly during summer.
In the evening the spider constructs an orb-web that can be up to 70 cm in diameter. A signaling thread leads from the web to her hiding place. After dusk she sits in the web's center.
This spider is capable of biting humans, causing itchiness and a burning sensation followed by a red patch with white lumps.
External links
- Platnick, Norman I. (2008): The world spider catalog, version 9.0. American Museum of Natural History.