Funnel-web Spider



The araneomorph funnel-web spiders of the family Agelenidae include the common grass spiders of the genus Agelenopsis, as well as the purportedly venomous European hobo spider, Tegenaria agrestis, which has been introduced into the Pacific Northwest of the United States. ''Note: The araneomorph funnel-web spider should not to be confused with the funnel-web tarantula and the venomous funnel-web tarantula, both of which are members of the suborder Mygalomorphae. The venomous funnel-web tarantulas include the infamous Sydney funnel-web spider.''

The family contains nearly 500 species in over 40 genera worldwide. Among other genera are Hololena and Agelena. The last named genus includes some fascinating semi-social spiders that live in complex communal webs in Africa. The best known of these is probably Agelena consociata.

Sociality in these spiders has gone so far as communal web-building and sharing; cooperative prey capture and communal rearing of young. Spiders have not, however, taken the final step into the eusociality of the social Hymenoptera (ants, bees and wasps) because there are no workers or soldiers (no castes) and all females are reproductive.

Most of these spiders are also known for their fast speed which, on the web, can reach 2 km/h (slow-paced pedestrian walk). Due to this ability, they practically rely solely on their movement while capturing prey, but, unlike similar families, Lycosidae for example, they prefer to stalk their prey by building randomly placed web sheets, which may include up to 100 times the spider's size and funnel down to a narrow nest, hence the spider's name.

Usually, Agelenids range from 12 to 20 mm in size, excluding legspan, and about 50 mm in the largest species, including it.

Agelenids have a reputation of giving bites that are highly venomous to humans, however, this observation has never been completely proven on practice. Of all the genera, Tegenaria species probably have the most potent venom, but cases of a medically considerable spider bite occurring from them are generally scarce. Ironically, Tegenaria duellica is the only species in the whole family whose bites can penetrate human skin far enough to inject venom into the lymphatic system (Tegenaria agrestis have recently proven to be unable to envenom humans overall).