The mygalomorph spider family Dipluridae (funnel-web spiders) includes 179 described species(Platnick 2013); most species are tropical, but five occur in North America north of Mexico (Coyle 2005; Bradley 2013). The family is perhaps best known for the dangerously venomous Sydney Funnel-web Spider (Atrax robustus) of Australia (Bradley 2013).
The two genera in the United States are found in the southwestern United States (Euagrus) and in the southern Appalachians and Pacific Northwest (Microhexura). Euagrus spiders are among the most common mygalomorphs in Mexico and Central America, with three species occurring in North America north of Mexico. Microhexura includes just two species (see below). Spiders in both genera build ground webs composed of flattened, often branching, tubular retreat passages connected to small, irregular sheets. These webs are often hidden under objects or in soft, porous organic substrates. Euagrus prefers riparian, woodland, and forest habitats. Euagrus webs are typically found beneath rocks, but inconspicuous irregular funnels and sheets often extend into surrounding leaf litter. Microhexura montivaga, a federally listed endangered species in the United States, is restricted to remnant patches of fir forest on a few high peaks in the southern Appalachian Mountains, where it lives almost exclusively under moss mats on rock outcrops. The other Microhexura species, M. idahoana, is widespread in Pacific Northwest conifer forests, where its webs are often common in or under rotting logs and other organic debris. (Coyle 2005)More information on the natural history of Microhexura can be found in Coyle (1981, 1985). Information on Euagrus can be found in Coyle (1988).
Diplurids have only four spinnerets, having lost the anterior pair. The median spinnerets have one short segment. The posterior spinnerets are long, widely spaced, and conspicuous. (Bradley 2013)
The family Dipluridae, known as curtain-web spiders (or confusingly with other distantly related ones as funnel-web tarantulas[2]) are a group of spiders in the infraorder Mygalomorphae, that have two pairs of booklungs, and chelicerae (fangs) that move up and down in a stabbing motion. A number of genera, including that of the Sydney funnel-web spider (Atrax), used to be classified in this family but have now been moved to Hexathelidae.
Dipluridae lack a rastellum (stout conical spines) on their chelicerae. Their carapace is characterized by the head region not being higher than the thoracic region. Their posterior median spinnerets (silk-extruding organs) are much shorter than their posterior lateral spinnerets, which have three segments, and are elongated (almost as long as their opisthosoma). Most of the species are medium to small-sized spiders; some may measure about 15 mm.[3] The cave species Masteria caeca is eyeless.
Members of this family often build rather messy funnel-webs. Some build silk-lined burrows instead of webs (Diplura, Trechona, some Linothele sp.). They generally build their retreats in crevices in earthen banks, the bark of trees, under logs or in leaf litter.[3]
As circumscribed as of July 2020, the family is mostly found in South America and the Caribbean, with some genera found in Australia and Oceania.[4]
As of July 2020, the World Spider Catalog accepted the following genera:[4]
The following genera are now placed in other families (elevated from subfamilies):[5][6]
Extinct genera and species that have been placed in this family include:[7]
Masteria petrunkevitchi eye pattern The family Dipluridae, known as curtain-web spiders (or confusingly with other distantly related ones as funnel-web tarantulas) are a group of spiders in the infraorder Mygalomorphae, that have two pairs of booklungs, and chelicerae (fangs) that move up and down in a stabbing motion. A number of genera, including that of the Sydney funnel-web spider (Atrax), used to be classified in this family but have now been moved to Hexathelidae.
