Orb Web Spider

Zygiella x-notata

                                 Araneus is a genus of common orb-weaving spiders. It includes about 650 species.Spiders of this genus present perhaps the most obvious case of sexual dimorphism among all of the orb-weaver family, with males being normally 1/3 to 1/4 the size of females. In A. diadematus, for example, last molt females can reach the body size of up to 1 in (2.5 cm), while most males seldom grow over 0.3 in (1 cm), both excluding legspan. Males are differentiated from females by a much smaller and more elongated abdomen, longer legs, and the inability to catch or consume prey bigger than themselves.n females, the epigyne has a long scape (a tongue-like appendage). Male pedipalps have a hook-like terminal apophysis. Abdominal tubercles are present anterolaterally.
                                  Araneus was originally called Epeira. The latter name is now considered a junior synonym of Araneus.It was first coined by Charles Athanase Walckenaer in 1805, for a range of spiders now considered Araneidae (orb-weavers). Over time, a rather diverse set of spiders was grouped under the genus Epeira, including species from the modern families Araneidae, Mimetidae (Mimetus syllepsicus described by Hentz, 1832), Nephilidae, Tetragnathidae, Theridiidae, Theridiosomatidae (Theridiosoma gemmosum, described by L. Koch, 1877 as Theridion gemmosum), Titanoecidae (Nurscia albomaculata, described by Lucas, 1846 as Epeira albo-maculata) and Uloboridae (Uloborus glomosus, described by Walckenaer, 1842 as Epeira glomosus). Epeira cylindrica O. P-Cambridge, 1889 was at a time placed in Linyphiidae and is considered incertae sedis, as is "Araneus" cylindriformis
                               The short documentary "Epeira diadema" (1952) by Italian director Alberto Ancilotto was nominated for an Oscar in 1953. It is about the spider today known as Araneus diadematus.
                             Araneus spiders possess various venoms, but will deliver a dry bite on 8 of 10 occasions. Females bite more often than males, who would rather flee or feign death.
                                Z. x-notata females are up to 11mm in size, males up to 7mm. The prosoma is yellow-brown, with a leaf-like mark on the opisthosoma. In moderate climate, adults appear from July to October, sometimes even into December. In warmer regions, they are active all year.
                                           
                              This spider builds its web mostly into window frames, but can also be found on walls, fences, or under the bark of old trees. It is very common around boats and docks throughout the world.
Adult spiders build an orb-web with two sectors without connecting threads in one of the two upper corners. The signalling thread in the middle of these sectors leads to the spider's hideout. In the evening and at night, however, the spider sits in the center of the web. It renews the web in the morning hours.
A normal web consists of about 25 to 30 radial threads. Young spiders, and sometimes adults, build webs without the free sectors, especially if the angle between signalling thread and radii gets too big.
    
Special Feature      
   
               Catching prey is instinctive in Zygiella in which it differs from other Araneidae, who have to learn this behavior. When alerted by movements of caught prey, the spider moves along the signalling thread into the web center, to orient itself. The killed and wrapped prey is moved to the hideout.

Taxonomy

Kingdom :  Animalia
Phylum :     Arthropoda
Class :        Arachnida
Order :       Araneae
Family :      Araneidae
Genus :       Zygiella
Species :     Zygeilla x-notata   

Source : 1)http://en.wikipedia.org/wiki/Araneus 2)http://en.wikipedia.org/wiki/Zygiella_x-notata 3)http://www.richard-seaman.com/Arthropods/PhotoGalleries/Spiders/index.html 4)http://ednieuw.home.xs4all.nl/Spiders/Araneidae/Araneidae.htm 5)http://www.eurospiders.com/Zygiella_x-notata.htm