The spider family Oecobiidae includes 110 described species (Platnick 2013), including eight that occur in North America north of Mexico. The members of this family have a distinctive appearance and are unlikely to be mistaken for anything else, although they bear a superficial resemblance to Euryopsis (family Theridiidae). Oecobiids have a large anal tubercle that is fringed with long bristles and a subcircular carapace with the eight eyes arranged in a central cluster. (Craig et al. 2005). The bristles spread the capture silk emitted from enlarged posterior spinnerets as the spider wraps its prey (Bradley 2013). Two species (Oecobius cellariorum and Oecobius navus) are widespread in the United States and southeastern Canada—and, in fact, have cosmopolitan distributions (Platnick 2013). In the United States, Oecobius interpellator has been recorded only from Massachusetts and other species of Oecobius are southern. The only other oecobiid genus represented in the United States, Platoecobius, occurs from South Carolina to Florida (P. floridanus), with an apparently undescribed species occurring in southern California. Oecobius are considered to be among the most common human-associated spiders. (Craig et al. 2005)
Oecobius species are found on and under rocks, as well as around human habitation. They typically lie concealed within small sheet webs placed over cavities. The distinctive webs consist of two horizontal sheets. The spider is positioned on the lower sheet and covered by the upper, which has radiating signal lines that give the web a star-shaped appearance. When potential prey touch these lines, the spider emerges and runs rapidly around the prey, periodically changing direction, swathing it in silk. (Craig et al. 2005; Bradley 2013)At least some oecobiids apparently do not construct webs. For example, Platoecobius floridanus, which has been collected under pine scales, is not known to construct a web (Chamberlin and Ivie 1935).
Oecobius are believed to feed heavily on ants, although Liznarova et al. (2013) concluded that the O. navus in their study were simply feeding on locally abundant prey, not necessarily ants; Shear (1970) observed Oecobius in Florida (U.S.A.) feeding on tiny flies. Oecobius spiders often form large aggregations and at least some are reported to be communal. Mating occurs in special webs contructed by the male adjacent to the web of the female. Female egg sacs contain just 3 to 10 eggs, but females provide no maternal care. (Glatz 1967 cited in Shear 1970; Shear 1970)
Craig et al. (2005) note that the recognition by some authors that Oecobiidae includes both cribellate and ecribellate species provided early evidence that the presence of a cribellum was a phylogenetically labile character (its presence apparently being an ancestral trait that has been lost in many lineages) and could not be used to define a monophyletic group (a point later firmly established by Lehtinen 1967).
Oecobiidae, also called disc web spiders, is a family of araneomorph spiders, including about 100 described species.[1] They are small to moderate sized spiders (about 2 to 20 millimetres (0.079 to 0.787 in) long combined head and body length, depending on the species. Larger ones tend to be desert-dwelling. The legs are unusually evenly placed around the prosoma; most other spiders have some legs directed clearly forward and the rest clearly backward, or all forward. The first two pairs of legs of many Oecobiids point forward then curve backwards; somehow in a running spider this gives a curiously scurrying, wheel-like impression that is characteristic of many Oecobiidae, and is helpful as a rough-and-ready aid to identification in the field. Characteristic of the family is the anal gland; it bears a tuft of long hairs. Typical colour patterns range from dark-patterned cream in some smaller species, to a small number of symmetrically-placed, conspicuous round light spots (commonly yellow or white) on a background that may be anything from a dull orange colour to black. The carapace is rounded and bears a compact group of six to eight eyes medially situated near the front of its dorsal surface.[2]
Many Oecobiidae build small, temporary star-shaped webs on or under rocks, or on walls or gravel. They hide near or below such webs and prey largely on ants, giving rise to common names such as "anteater" or "miervreter" (Afrikaans for anteater).[2] Some of the Oecobiidae build tiny webs close to the ceilings in people's homes, which might have something to do with the family name (Oeco biidae meaning in essence "those who are house-living"[3]).
The species Oecobius navus occurs around the world.
While the genus Oecobius is cribellate, the genus Uroctea is ecribellate.
As of April 2019, the World Spider Catalog accepts the following genera:[1]
Oecobiidae, also called disc web spiders, is a family of araneomorph spiders, including about 100 described species. They are small to moderate sized spiders (about 2 to 20 millimetres (0.079 to 0.787 in) long combined head and body length, depending on the species. Larger ones tend to be desert-dwelling. The legs are unusually evenly placed around the prosoma; most other spiders have some legs directed clearly forward and the rest clearly backward, or all forward. The first two pairs of legs of many Oecobiids point forward then curve backwards; somehow in a running spider this gives a curiously scurrying, wheel-like impression that is characteristic of many Oecobiidae, and is helpful as a rough-and-ready aid to identification in the field. Characteristic of the family is the anal gland; it bears a tuft of long hairs. Typical colour patterns range from dark-patterned cream in some smaller species, to a small number of symmetrically-placed, conspicuous round light spots (commonly yellow or white) on a background that may be anything from a dull orange colour to black. The carapace is rounded and bears a compact group of six to eight eyes medially situated near the front of its dorsal surface.
Many Oecobiidae build small, temporary star-shaped webs on or under rocks, or on walls or gravel. They hide near or below such webs and prey largely on ants, giving rise to common names such as "anteater" or "miervreter" (Afrikaans for anteater). Some of the Oecobiidae build tiny webs close to the ceilings in people's homes, which might have something to do with the family name (Oeco biidae meaning in essence "those who are house-living").
The species Oecobius navus occurs around the world.
While the genus Oecobius is cribellate, the genus Uroctea is ecribellate.
