tube web spider poisonous
There is no need to worry, though – this is a secretive and reclusive creature. It is uncommon and currently restricted to southern Britain, usually ports and market towns, and its venomous bite is said to be painful, but not dangerous.
tube web spider size
The tube web spider (Segestria florentina) is a spectacular beast. Its body length can measure up to 22mm, making it one of the biggest spiders in the UK.
Its chelicerae (fanged mouthparts), often described as shining bottle green, are its most distinctive feature, and usually all that is visible when it is inside its hideaway, normally a hole in an old wall.
The long, radiating strands of its web act like trip wires, alerting the spider to passing prey. When it detects movement, it rushes out and pounces.
Tube spiders build aerial tubes, open at the top, that are supported against rocks, stems, tree trunks or buttress roots.
Identification
Tube spiders are large brown, burrowing spiders. They are unexceptional apart from their remarkable habit of building aerial tubes that extend their burrows well above the ground. Their numerous relatives in the genus Misgolas build burrows with ground-level openings that are commonly seen in bushland and gardens in eastern Australia.
Habitat
Tube spiders can be found in considerable numbers in suitable habitats. They were recorded as far back as 1922, in an article published in the Sydney Mail newspaper (they were not taxonomically described until 1974). The report noted that the tubes were present in thousands on damp ground sloping down to creeks in coastal rainforest patches of the Myall Lakes region of New South Wales. Such abundance is rare today.
The aerial tubes, open at the top, are supported against rocks, stems, tree trunks or buttress roots. Sometimes they occur in clusters ‘like miniature organ pipes’. Each tube is attached to its supporting structure only by the silk collar at the tube’s mouth – the rest simply lies alongside the support or even hangs free of it. Tubes can reach 30 centimetres in height, although one older report has a tube extending ‘up to three feet’ (about 90 cm). The tubes are made of thin, parchment-like silk, often admixed with soil particles and adorned with moss. The tube wall thickens at ground level but it is only weakly attached to the finer silk of the burrow below, which descends 15 to 20 cm to a sock-like, silken retreat chamber. When hunting, the spider usually sits in the tube mouth waiting to ambush any prey passing nearby.
Why build these curious aerial tubes? Tube spiders are found in moist forest habitats that may be prone to waterlogging or flooding, such as rainforest creek banks and gullys. Consequently, one function of the aerial tube may be to provide an above ground retreat for the spider during rainfall-induced sheet flooding or creek overflows. In addition, the tube elevates the spider into a feeding niche above the forest floor. This would allow these spiders to intercept insect and other prey moving across rocks or between ground and foliage along stems, so avoiding direct feeding competition with ground dwelling spiders. Prey animals can even use the tube itself as an aerial walkway. The tube may then act as an early warning system that alerts the spider to the presence of prey, as well as a means of delivering prey directly to the spider waiting above.
They spin a tubular web, often in cracks of buildings. Six or more silken lines radiate from it, and the spider waits in the entrance, touching the lines with the frontal six legs. Prey triggering these lines get caught, and the spider immediately retreats again to eat it. However, in some cases the spider will kill and begin to consume its prey in the opening of the tube, but will retreat further if disturbed. They hunt nocturnal insects such as moths and cockroaches. Bees and wasps are always bitten at the head end, so the sting will face away from the spider.
The female lays her eggs inside the tube web. Sometimes she will die after the spiderlings have hatched, and they will eat their mother.[5] The spider can be lured to the entrance by gently touching the triplines with a stick in the evening or at night.
Distribution
Tube spiders are found sporadically in moist forest habitats, especially in rainforests and their margins. Southern Tube Spiders are known from highland and coastal forests in New South Wales from the Macleay River to the Illawarra region. Northern Tube Spiders range from the Dorrigo region of New South Wales into south eastern Queensland.
Females can reach a body length of 22 mm, males up to 15 mm. This species is much darker than others of the same genus. While subadult spiders have a greyish opisthosoma with a marking similar to Segestria senoculata, adults are of a uniform black, sometimes with a green iridescent shine, especially on the chelicerae, which reflect with a striking green. The sexes are similar. Adults occur from June to November.
The tube web spider (Segestria florentina) is a large, black and intimidating looking spider. With females reaching up to 22mm in body length this makes them one of the largest spiders found in Britain. As if to emphasise they mean business the spiders frequently have iridescent green fangs (you can just make out this on the photo above).
The name tube web comes from their tubular web which they spin into a crack or crevice. From the opening they lay six or more threads of silk radiating outwards. The spider generally keeps one leg on each thread and waits. When some unfortunate prey touches one of these threads the spider bolts out of its lair and sinks its prodigious fangs into it.
The spider can often be lured out of its retreat by tapping the trip-lines after sun down, if you are brave enough!
In common with the lace weaver spider, the tube web is matriphagous. That is the young devour the mother after hatching.
Like the false widow spider, the tube web is another immigrant to the UK. First recorded in 1845 the spider has made steady inroads into the UK and can now be found across much of southern England.
Also similar to the false widow is the painful bite. Although not quite as venomous as Steatoda nobilis the bite is still reported to be about as painful as a bee sting, or as one report puts it “…felt like a deep injection…”, with the pain lasting several hours.
The venom itself has been shown to contain 2 neurotoxins and one insecticide.
