Segestria florentina is the biggest Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

an segestriid spider

Spider

Spiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...

. Some common names are tube web spider or cellar spider, although neither are exclusive to this species.

Description

Females 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

Opisthosoma

The opisthosoma is the posterior part of the body in some arthropods, behind the prosoma . It is a distinctive feature of the subphylum Chelicerata...

 with a marking similar to Segestria senoculata

Segestria senoculata

Segestria senoculata, sometimes known as the snake-back spider or leopard spider, is a species of spider belonging to the family Segestriidae...

, adults are of a uniform black, sometimes with a green metallic shine, especially on the fangs, which reflect with a striking green. The sexes are similar. Adults occur from June to November.

Habits

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 in its retreat. They hunt nocturnal insects such as moth

Moth

A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...

s and cockroach

Cockroach

Cockroaches are insects of the order Blattaria or Blattodea, of which about 30 species out of 4,500 total are associated with human habitations...

es. Bee

Bee

Bees are flying insects closely related to wasps and ants, and are known for their role in pollination and for producing honey and beeswax. Bees are a monophyletic lineage within the superfamily Apoidea, presently classified by the unranked taxon name Anthophila...

s and wasp

Wasp

The term wasp is typically defined as any insect of the order Hymenoptera and suborder Apocrita that is neither a bee nor an ant. Almost every pest insect species has at least one wasp species that preys upon it or parasitizes it, making wasps critically important in natural control of their...

s are always bitten at the head end, so the sting will face away from the spider.

The eggs are deposited inside the tube web. Sometimes the female will die after the spiderlings have hatched, and they will eat their mother. The spider can be lured to the entrance by gently touching the triplines with a stick in the evening or at night.

Distribution

Originally a species of the Mediterranean region as far east as Georgia

Georgia (country)

Georgia is a sovereign state in the Caucasus region of Eurasia. Located at the crossroads of Western Asia and Eastern Europe, it is bounded to the west by the Black Sea, to the north by Russia, to the southwest by Turkey, to the south by Armenia, and to the southeast by Azerbaijan. The capital of...

, it can now be found in several large British towns (for example Bristol

Bristol

Bristol is a city, unitary authority area and ceremonial county in South West England, with an estimated population of 433,100 for the unitary authority in 2009, and a surrounding Larger Urban Zone with an estimated 1,070,000 residents in 2007...

), where they were probably introduced via seaports at least since 1845. It has been found in several places in Cornwall

Cornwall

Cornwall is a unitary authority and ceremonial county of England, within the United Kingdom. It is bordered to the north and west by the Celtic Sea, to the south by the English Channel, and to the east by the county of Devon, over the River Tamar. Cornwall has a population of , and covers an area of...

, Bristol

Bristol

Bristol is a city, unitary authority area and ceremonial county in South West England, with an estimated population of 433,100 for the unitary authority in 2009, and a surrounding Larger Urban Zone with an estimated 1,070,000 residents in 2007...

, Gloucester

Gloucester

Gloucester is a city, district and county town of Gloucestershire in the South West region of England. Gloucester lies close to the Welsh border, and on the River Severn, approximately north-east of Bristol, and south-southwest of Birmingham....

 and Sheffield

Sheffield

Sheffield is a city and metropolitan borough of South Yorkshire, England. Its name derives from the River Sheaf, which runs through the city. Historically a part of the West Riding of Yorkshire, and with some of its southern suburbs annexed from Derbyshire, the city has grown from its largely...

, where it prefers south-facing walls.. Specimens have been found in Exeter Cathedral

Exeter Cathedral

Exeter Cathedral, the Cathedral Church of Saint Peter at Exeter, is an Anglican cathedral, and the seat of the Bishop of Exeter, in the city of Exeter, Devon in South West England....

 as far back as 1890. It has also been found in Argentina

Argentina

Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

, Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

 and several Atlantic

Atlantic Ocean

The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...

 islands, where it was probably also introduced.

Bite

Its bite is reportedly quite painful. It has been compared to a "deep injection", and the pain can last for several hours.

Two neurotoxin

Neurotoxin

A neurotoxin is a toxin that acts specifically on nerve cells , usually by interacting with membrane proteins such as ion channels. Some sources are more general, and define the effect of neurotoxins as occurring at nerve tissue...

s and one insecticide

Insecticide

An insecticide is a pesticide used against insects. They include ovicides and larvicides used against the eggs and larvae of insects respectively. Insecticides are used in agriculture, medicine, industry and the household. The use of insecticides is believed to be one of the major factors behind...

 were found in the venom.
The venom reduces the rate and amount of sodium inactivation. This effect is probably responsible for the prolongation of the action potential

Action potential

In physiology, an action potential is a short-lasting event in which the electrical membrane potential of a cell rapidly rises and falls, following a consistent trajectory. Action potentials occur in several types of animal cells, called excitable cells, which include neurons, muscle cells, and...

.