Eratigena atrica

Classification

Phylum: Arthropoda
Subphylum: Chelicerata
Class: Arachnida
Order: Araneae
Infraorder: Araneomorphae
Family: Agelenidae
Subfamily: Ageleninae
Genus: Eratigena
Species: atrica

Pronunciation

How to pronounce Eratigena atrica: //ˌɛr.əˈtɪ.dʒə.nə əˈtraɪ.kə//

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Summary

Eratigena atrica, known as the giant house spider, is among the largest spiders in Central and Northern Europe, with a primarily brown coloration. This spider is often found in homes, builds funnel-webs, and is not generally aggressive towards humans.

Physical Characteristics

Mainly dark brown coloration with lighter markings on the sternum, an arrow-like shape pointing to the head. Six spots on each side of the opisthosoma. Hairy legs, palps, and abdomen. Female body size can reach 18.5 mm, males slightly smaller at around 12 to 15 mm. Female leg span typically around 45 mm, male leg span varies between 25 to 75 mm.

Identification Tips

Sexes do not differ in coloration or markings; similar coloration to the domestic house spider, Tegenaria domestica. Eight equal-sized eyes arranged in two rows.

Habitat

Originally found in caves and dry forests under rocks; commonly found in human homes.

Distribution

Native to Europe, Central Asia, and Northern Africa; introduced to the Pacific Northwest of North America circa 1900; recorded in Estonia, Latvia, Lithuania, and also found in Iceland.

Diet

Primarily feeds on small invertebrates caught in its funnel-web.

Life Cycle

Typically lives for 2 to 3 years, with max observed lifetimes of up to 6 years. Spiderlings emerge from an egg-sac and remain together for about a month.

Reproduction

At least 60 spiderlings emerge from an egg-sac. Males are wandering in late summer and early autumn in search of mates.

Ecosystem Role

Potentially competes with other spiders like Eratigena agrestis for resources.

Cultural Significance

Featured in a humorous essay by David Sedaris, documenting a personal affection towards the giant house spider.

Health Concerns

Bites can penetrate human skin but pose minimal threat; they are generally reluctant to bite without provocation.

Evolution

Originally classified in the genus Tegenaria, reclassified to Eratigena in 2013; distinction of three species restored in 2018 due to genetic studies.

Misconceptions

Bite poses minimal threat to humans; more associated with avoidance than aggression.