The European garden spider (Araneus diadematus), diadem spider, or cross spider, is a very common and well-known orb-weaver spider in Western Europe. Araneus diadematus also lives in parts of North America, in a range extending from New England and theSoutheast to California and the Northwestern United States and adjacent parts of Canada.
Individual spiders’ colouring can range from extremely light yellow to very dark grey, but all European garden spiders have mottled markings across the back with five or more large white dots forming a cross. The white dots result from cells that are filled with guanine, which is a byproduct of protein metabolism.
(From Wikipedia, June 26th, 2010)
The garden spider spins a large complex orb-web, which measures up to 40 cm in diameter and is used to capture insect prey (1). Individuals spend much of their time at the centre of their web, and detect vibrations in the silk through their legs when insects become trapped. This spider wraps prey items in silk before consuming them (3). When this species is threatened, it rapidly shakes itself and the web up and down, and may drop to the ground on a silk thread (1). The web may be rebuilt every day, and the old web is consumed so that the proteins used in its construction are conserved and re-used (3). Males approach females with caution in order to avoid being eaten. During copulation, males embrace the female’s abdomen; sperm is transferred by the insertion of one of the male’s palps. The male departs after mating, and the female spends a number of days inside her retreat. She then begins to spin an egg sac or ‘cocoon’, which protects the eggs. She stays close to the cocoon for a number of days before dying (3). The young spiders emerge from the cocoon in spring (3); they gather into dense groups until after their first moult (1), after which they disperse by ‘ballooning’, a form of dispersal in which the spiderlings are carried on the wind by a thread of silk (3). The word ‘spider’ derives from the Old English word ‘spithra’ and is related to the German ‘spinne’, both of which mean ‘spinner’ (8). Spider webs have been used to heal wounds and to staunch blood flow for many years (7).
The ultimate purpose of spider webs is to capture prey and orb webs are well-suited for this. They are highly geometrical, with the hub slightly higher than the center so that the spider may run down the web quickly. The area nearer the hub is coated more densely with sticky globules. Araneus diadematusindividuals spend most of their time on the web’s hub monitoring vibrations in the silk with their sensitive legs. Females rest on one side of the web and monitors by holding onto a signal thread. When catching prey, Araneus diadematus individuals wrap prey in silk thread before consuming it. After killing and wrapping their prey, these spiders may not immediately consume the prey. The number of prey attacked and killed may decrease as the number of prey increases and the spiders become satiated. Spiders eat primarily arthropod prey. (Foelix, 1982; Preston-Mafham and Preston-Mafham, 1996; Wise, 1993)
(From EOL via Animal Diversity Web)