Bevan - European Garden Spider

Araneus Diadematus (European Garden Spider)

Phylum: Arthropoda Class: Arachnida Order: Araneae Family: Araneidae

The European garden spider is very common across all of Europe and is also found in parts of Northern Europe. It is also called the “Cross Spider” from the white cross shapes it forms on its abdomen from cells filled with guanine. The color can range from ginger to dark grey. Two of these spiders accompanied the Apollo spacecraft in 1973 for experimentation and it was found they could build their webs in micro-gravity conditions. As being from the Araneidae family or orb-weavers they build wheel shaped web we commonly see. When building a web they send out a silk string in the wind and attach it to another surface then climb halfway across it and send out another string forming a “Y” shape. They then build the rest of their web this way. Individual strings are about 2.0mm thick and have a similar strength to an equivalent amount of steel. They have six spinnerets at their rear, four for making silk to build webs and two that produce a fluid to aid the trapping of prey. They remain on the web and let their

prey hit it and get caught in it. The spider has sensory organs in its front legs that feel vibrations in the web when something hits it. It then rushes to its prey and quickly wraps it up in silk. It is unable to eat the prey directly so must inject digestive enzymes into it and sucks out the resulting liquid leaving a crumpled mass of undigested pieces still wrapped in silk. The spider is known to stridulate when threatened (rub certain body parts together to make a noise like a cricket does. The female is bigger than the male with an abdomen bigger in proportion to the rest of her body. The male approaches the female carefully for mating as it can be mistaken for food. When close, the male secretes sperm onto a special sperm web then collects it with palps and inserts the palps into the female’s epigrastic furrows.

The male will die shortly after. The semen is stored in semen receptacles until the eggs are released. The female looks for a good place to lay the eggs, usually a crevice in bark or a wall. She uses a web cocoon which she makes from silk when she lays the eggs. She stays near the cocoon for repairs but she too, will die after a few days. The eggs have several stages of development and it is at first larvae that come out of the egg. There are more stages for these also before they become young spider lings. The spider lings quickly disperse because cannibalism happens often.