The spider family Agelenidae (funnel weavers) has a worldwide distribution (although mainly Holarctic, Neotropical, and Australian) and as of 2013 included 1,156 described species (Platnick 2013), including around 100 in North America north of Mexico. In the Nearctic portion of the Holarctic, only Agelenopsis and one species of Tegenaria (T. domestica) are very widespread (Bennett and Ubick 2005). Although some spiders in the genera Coras (Muma 1946; Wang 2002) and Wadotes (Muma 1947; Bennett 1987; Wang 2002) have sometimes been placed in the family Amaurobiidae rather than Agelenidae, based on their molecular phylogenetic analyses Miller et al. (2010) concluded that these and a number of other genera that had been placed in Amaurobiidae are clearly agelenids.
Agelenids are known as funnel weavers because they construct large, relatively flat sheets of non-sticky silk connected to a funnel-shaped tube. They typically spend much of their time in this tube or waiting at its entrance. When the web is disturbed, the spider may escape out a rear opening. Most agelenids are active at night, but they may rush out onto the sheet to capture prey even in daylight.
The number and arrangement of a spider's eyes are often helpful in determining to which family it belongs. Agelenids (like spiders in many other families) have eight eyes and in most genera these are arranged in two strongly procurved transverse rows, i.e., two rows of four, each of which has the lateral eyes set farther forward than the median eyes (these rows are straight or only slightly procurved in Tegenaria). Many agelenids have light brown bodies with paired darker longitudinal stripes on the cephalothorax (and sometimes on the abdomen as well). Many (although not all) agelenids have long and conspicuous posterior spinnerets that extend well beyond the tip of the abdomen. Their legs are relatively long and they are able to run very quickly. They rely on their speed, rather than on sticky silk, to capture prey that walk or hop or land on the web.
Some large-bodied Tegenaria species can be found living in buildings. A number of the Tegenaria species found in North America north of Mexico have been introduced from Eurasia. A notable example is the Hobo Spider (Tegenaria agrestis). which was introduced to the Pacific Northwest and has been expanding its range eastward. Although this species has developed a reputation as dangerous to humans, there seems to be little evidence supporting this (Binford 2001; Vetter and Isbister 2004, 2008; Gaver-Wainwright et al. 2011). There are a handful of records of bites by other agelenids that have produced significant and alarming symptoms in humans (Vetter 2012), but without any apparent long-term effects.
Agelenopsis aperta has been the focus of diverse studies of social behavior by Susan Riechert and colleagues (e.g., Riechert 1993 and references therein). Ayoub et al. (2005) analyzed species boundaries and patterns of speciation in Agelenopsis.
Bennett and Ubick (2005) and Bradley (2013) are useful resources for identifying agelenids in North America and Bolzern et al. (2013) is useful for Europe.
(Bennett and Ubick 2005; Bradley 2013)
- Ayoub, N.A., S.E. Riechert, and R.L. Small. 2005. Speciation history of the North American funnel web spiders, Agelenopsis (Araneae: Agelenidae): Phylogenetic inferences at the population–species interface. Molecular Phylogenetics and Evolution 36: 42-57.
- Bennett, R.G. 1987. Systematics and Natural History of Wadotes (Araneae, Agelenidae). Journal of Arachnology 15(1): 91-128.
- Bennett, R.G. and D. Ubick. 2005. Agelenidae. Pp. 56-59 in D. Ubick, P. Paquin, P.E. Cushing, and V. Roth (eds.) Spiders of North America: an Identification Manual. American Arachnological Society.
- Binford, G.J. 2001. An analysis of geographic and intersexual chemical variation in venoms of the spider Tegenaria agrestis (Agelenidae). Toxicon 39: 955-968.
- Bolzerni, A., D. Burckhardt, and A. Hänggi. 2013. Phylogeny and taxonomy of European funnel-web spiders of the Tegenaria-Malthonica complex (Araneae: Agelenidae) based upon morphological and molecular data. Zoological Journal of the Linnean Society 168: 723-848.
- Bradley, R.A. 2013. Common Spiders of North America. University of California Press, Berkeley.
- Gaver-Wainwright, M.M., R.S. Zack, M.J. Foradori, and L.C. Lavine. 2011. Misdiagnosis of Spider Bites: Bacterial Associates, Mechanical Pathogen Transfer, and Hemolytic Potential of Venom from the Hobo Spider, Tegenaria agrestis (Araneae: Agelenidae). Journal of Medical Entomology 48(2): 382-388.
- Miller, J.A., A. Carmichael, M.J. Ramirez, et al. 2010. Phylogeny of entelegyne spiders: Affinities of the family Penestomidae (NEW RANK), generic phylogeny of Eresidae, and asymmetric rates of change in spinning organ evolution (Araneae, Araneoidea, Entelegynae). Molecular Phylogenetics and Evolution 55 (3): 786-804.
- Muma, M.H. 1946. North American Agelenidae of the genus Coras Simon. American Museum Novitates No. 1329: 1-20.
- Muma, M.H. 1947. North American Agelenidae of the genus Wadotes Chamberlin. American Museum Novitates, No. 1334: 1-12.
- Platnick, N. I. 2013. The world spider catalog, version 14.0. American Museum of Natural History, online at http://research.amnh.org/entomology/spiders/catalog/index.html.
- Riechert, S.E. 1993. The evolution of behavioral phenotypes--lessons learned from divergent spider populations. Advances in the Study of Behavior 22: 103-134.
- Vetter, R.S. 2012. Envenomation by spiders of the genus Hololena (Araneae: Agelenidae). Toxicon 60: 312-314.
- Vetter, R.S. and G.K. Isbister. 2004. Do hobo spider bites cause dermonecrotic injuries? Annals of Emergency Medicine 44: 605-607.
- Vetter, R.S. and G.K. Isbister. 2008. Medical Aspects of Spider Bites. Annual Review of Entomology 53: 409-29.
- Wang, X.-P. 2002. A generic-level revision of the spider subfamily Coelotinae (Araneae, Amaurobiidae). Bulletin of the American Museum of Natural History, Number 269:1-150.