Tube web spider
One of the largest in the UK, the tube web spider is common in the south of England and uses 'fishing lines' to capture its prey.
Tube web spider
Segestria florentina
Identification
The female is a very impressive specimen growing to as much as 22mm in length, making this one of the largest spiders living in Britain. It is almost black in colour with iridescent green on the jaws. Males resemble females but have a smaller, slimmer abdomen.
Distribution
This spider is originally a Mediterranean species but it has spread during the last century to many other parts of the world. It is an introduced species in this country and for many years it has been associated with ports, mostly in the south of England. These include Bristol, Plymouth, Exeter, Weymouth, Bridport, Portsmouth, Dover, Sittingbourne, Chatham, Gravesend and Westminster. In the last few years it has also begun to spread in the London area and is now present in typical residential areas such as Hounslow, Clapham, Hammersmith and Chiswick. It is probably responding to climate change, particularly milder winters.
Behaviour
The tube web spider lives in holes in walls and in bark. The hole is lined with silk to make a tubular retreat. An area of lace-like silk surrounds the entrance and from this twelve or more straight threads, or 'fishing lines', radiate outwards. The spider waits near the entrance, with each of its six front legs in touch with one of the lines. It rushes out to seize prey, mostly insects, when the threads are disturbed. Prey is then dragged backwards into the spider's retreat.
Life cycle
The mating season is in July or August, when the spiders reach adulthood. The female lays eggs within the retreat and she remains with the young until they disperse. Sometimes she dies first and is eaten by the young.
Living with humans
This spider is capable of giving a bite, which can be quite painful, but it is not seriously venomous. Symptoms of pain and swelling are likely to disappear after 24 hours. The spiders normally remain in their retreats where they are harmless to humans, and they do not invade homes.
Toolbox
Until 1938 whale carcasses were buried in the Museum grounds so that their flesh would decay leaving only the skeletons.
