Spiders in the Agelenidae family 1, 2

On this page, Agelenidae family overview - Tegenaria genus

Agelenidae family overview

There are 508 species described so far, around 300 species are found in mainland U. S. and Canada, but only 11 of these can be found in the U. K. The general body shape of spiders in this family (minus the legs) is shown in the drawing below. The abdomen of U. K. species usually has chevron markings. They are sometimes called funnel weavers.

Aglenidae spider body shape

Below is a drawing showing the long, segmented spinnerets of spiders in this family. Indeed the spinnerets are so long that they can usually be seen from above as you look down on the spider.

Spinnarets of a spider in the Aglenidae family

Below is the carapace shape showing the layout of the eyes. All species in this family have eight eyes.

Carapace of the cob web spider (Aglenidae)

Spiders in this family tend to be hairy with long, hairy legs. They have closely-woven sheet webs with a silken tunnel or funnel attached where the spider rests and the female keeps her egg sac. They capture prey by running and biting prey as it lands on the web. The largest U. K. species may be able to bite through human skin if they are roughly handled, but most individuals are just too small.

Tegenaria genus

There are nine British species, although some experts now say that T. gigantea/duellica and T. atrica should be considered a single species. Spiders in the Tegenaria genus can have a leg-span of over 10 cm, and it is the males which have the really long legs. The Tegenaria sp. are the big hairy spiders we commonly find wandering round our houses in autumn. They are also one of the most common spiders to be found in the bath. Spiders found in the bath have usually fallen in from above and can't get out, and not climbed up and through the plughole as is usually assumed. We usually find males (see the photographs below, and on the next page) as the females tend to stay on their webs.

The males look very similar to the females except they are a few mm smaller in the body, have a thinner abdomen, longer legs and usually have swollen palps (see the photographs below) as they are in search of a mate.

Tegenaria duellica mature male showing palps, chelicera, fang and eyes

Below you can just make out the sclerotised entrance to the female's epigyne, this is the opening into which the male must place one of his sperm-charged palps.

tegenaria epigyne

After a successful mating the males will usually live beside the females for a while, but die before winter. This provides the female with a substantial meal to see her through cold weather.

Tegenaria can live for several years especially if they are in a sheltered location such as a house or closed metal shed. The webs can be pretty untidy, and often have a tubular retreat. Above the female is on her web, note the long palps, these are always in contact with the web to detect any vibration indicating the presence of a possible snack.

Tegenaria egg sacs

Tegenaria females keep their egg sacs in the web covered with bits of debris and another layer of silk. The spiderlings normally disperse without eating their mother. In the U. K. females can produce around ten egg sacs each holding 40 - 60 eggs.

In 1760 when malaria, also known as ague, was common in Britain a Dr. Watson recommended a Tegenaria sp. "gently bruised and wrapped up in a raisin or spread upon bread and butter" as a cure !

In France Tegenaria sp. are released into wine cellars as the presence of their webs is though to create feeling of age.