Garden spider (Araneus diadematus)

Kingdom	Animalia
Phylum	Arthropoda
Class	Arachnida
Order	Araneae
Family	Araneidae
Genus	Araneus (1)
Size	Male length: 4-8 mm (2) Female length: 10-13 mm (2)

The garden spider is widespread and very common (1).

The garden spider (Araneus diadematus) is a very common, large orb-web spider (1). The colour is variable, ranging from pale yellow to blackish-brown (2), with pale markings on the abdomen which often take the form of a cross (1). Females are larger than males (2). Newly hatched spiderlings have yellow abdomens with a dark patch (1). As with all spiders, there are four pairs of legs (3); the first pair are long and are used to sense vibrations on the web (8). In front of the walking legs there is also a pair of leg-like 'palps', which are used for sperm-storage in males and are inserted into the female's body to transfer sperm (6). At the tip of the abdomen there are three pairs of spinnerets, which secrete silk (8).

The garden spider is common and widespread throughout Britain and northern Europe (4). It is also found in the northern states of the USA (3).

The garden spider is found in a very wide range of habitats, including gardens, meadows, woodland clearings and hedgerows (5).

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).

There are not known to be any theats to this common and widespread species.

There are not known to be any specific conservation measures currently in place for the garden spider.

For more on the garden spider see:

• The Animal Diversity Web: 
  http://animaldiversity.ummz.umich.edu/accounts/araneus/a._diadematus$narrative.html

For more on British spiders see:

• The British Arachnological Society:
  http://www.britishspiders.org.uk

Information authenticated by Dr Peter Merrett of the British Arachnological Society:
http://www.britishspiders.org.uk/index.html

• Abdomen: in arthropods (crustaceans, insects and arachnids) the abdomen is the hind region of the body, which is usually segmented to a degree (but not visibly in most spiders). In crustacea (e.g. crabs) some of the limbs attach to the abdomen; in insects the limbs are attached to the thorax (the part of the body nearest to the head) and not the abdomen. In vertebrates the abdomen is the part of the body that contains the internal organs (except the heart and lungs).
• Palps: in invertebrates, palps are sensory appendages located near the mouth.
• Spinnerets: tube-like, movable silk handling structures found at the tip of the abdomen (the hind region of the body) in spiders. There are four pairs of these organs, but in most species there are fewer (usually three). The silk is produced by the silk organs as a liquid, which passes through the spinnerets and is put under tension until the silk becomes a solid thread.

1. National Biodiversity Network Species Dictionary (Jan 2003):
   http://www.nhm.ac.uk/nbn/
2. Roberts, M. J. (1993) The spiders of Great Britain and Ireland, part 1- text. Harley Books, Colchester.
3. Araneus diadematus. Animal Diversity Web. (March 2003):
   http://animaldiversity.ummz.umich.edu/accounts/araneus/a._diadematus$narrative.html
4. Peter Merrett (2003) Pers. comm.
5. Nichols, D., Cooke, J. & Whiteley, D. (1971) The Oxford Book of Invertebrates. Oxford University Press, Oxford.
6. Roberts, M. J. (1995) Collins field guide- spiders of Britain and Northern Europe. Harper Collins Publishers, London.
7. Sterry, P. (1997) Complete British Wildlife photo guide. Harper Collins Publishers, London.
8. Buczacki, S. (2002) Fauna Britannica. Hamlyn, London.