The Cross Orb Weaver or Common Garden Spider Facts
Where Can They Be Found?
The cross orb-weaver spider, also known as 'araneus diadematus', 'the common garden spider' or 'diadem spider' is one of many orb-weaver spider varieties. The species is thought to have been introduced from Europe, where it is widely spread and common, and it can also currently be found in Pennsylvania, New England, Washington, Oregon and some parts of Canada.
Cross orb-weavers are usually found around buildings with exterior lighting - possibly because insects are attracted to the light and so the spiders are more successful in the amount of food they catch in their webs. They are mostly found in rural areas and gardens. The larger females build webs and lie in the center of them, facing down towards the ground, or they may take refuge in foliage next to their web with one 'signal' thread of the web attached to a leg. They do this so that when prey becomes caught in the web, the spider will sense the vibrations, and will quickly scurry down the web to wrap the prey in silk threads before eating it.
Safely Move Unwanted Guests Outside
Size And Coloration
Mature, adult females are significantly larger than the males (which is the case in almost all spider species), and tend to grow between 6.5 and 20 millimetres, whereas males are usually between 5.5 and 13 millimetres.
In terms of coloration, it seems that each individual specimen is slightly different, but the main background colour of the spider is a medium or pale brown. There are at least five white or cream-coloured spots around the folium, which are there because of cells which are filled with gaunine (a by-product of protein metabolism). There are also two slightly curved longitudinal lines that can also be seen on the folium.There are four elongated spots towards the anterior end of the abdomen, which looks like a cross (hence being called the 'cross' orb-weaver spider). The carapace has three black or dark brown longitudinal bands. Smaller, younger individuals are generally darker and the larger, adult females are overall much lighter.
The average lifespan of a cross orb-weaver is thought to be just 12 months, although experts say this is hard to gauge due to the fact that so many are killed or eaten within this time by birds, cats and other spiders. On the very rare occasion that a human does get bitten by this species, it is because the spider was provoked. The bite can sometimes pierce the skin, though it usually doesn't and although it is an uncomfortable and unpleasant pinching sensation, it is not actually painful. In addition to this, the cross orb-weaver's bite is completely harmless to humans.
Do You Worry About Spiders?
Females lay between 300 and 900 eggs in late September, and they usually lay these in safe, sheltered areas of gardens, such as between rocks, between cracks and crevices in garden walls and underneath dead tree bark. The eggs are tiny and are all enclosed in a hemisphere-shaped cocoon made of fine silk threads which are a pale yellow in colour.
Like most other orb-weaver varieties, if a cross orb-weaver feels threatened, she will create a defensive display which involves using her legs to shake the web. This is to ward off potential predators, but if this fails, she will run into the foliage near her web to escape as the species is incredibly passive.
Some Interesting Facts
Interestingly, most cross orb-weavers eat their webs every night (they have been observed doing this and it normally takes them just a matter of minutes), they are thought to do this so that they are able to eat any smaller insects that have gotten stuck on the silk threads of the web, and also to protect themselves. Every morning a new web is spun, and the cycle begins all over again.
Some of the fossils that have been found and inspected by palaeontologists and other experts suggest that some spider species (the cross orb weaver included), were around some 140 million years ago! It is likely that they started life in a similar form to how we know them now in the Jurassic period!
Without spiders, we would suffer hugely as a species. Biting insects which suck the blood of humans and other mammals would be even more of a nuisance, there would potentially be a wider range of diseases spread by flies and other insects and certain birds and other species would be missing out on a vital food source!
Out of the hundreds of thousands of spider species known to man, the number of ones capable of causing significant harm to humans can probably be counted on one hand. Even the species capable of delivering a bite with enough venom to cause problems, very rarely do, and never bite unless provoked (either directly through inappropriate handling), or indirectly through being disturbed when hiding in a shirt or item of clothing which is then picked up and put on, trapping the spider.