Orb-weaver spiders are members of the spider family Araneidae. They are the most common group of builders of spiral wheel-shaped webs often found in gardens, fields, and forests. The English word "orb" can mean "circular", hence the English name of the group. Araneids have eight similar eyes, hairy or spiny legs, and no stridulating organs.
A bolas spider is a member of the orb-weaver spider that, instead of spinning a typical orb web, hunts by using one or more sticky "capture blobs" on the end of a silk line, known as a "bolas". By swinging the bolas at flying male moths or moth flies nearby, the spider may snag its prey rather like a fisherman snagging a fish on a hook. Because of this, they are also called angling or fishing spiders. The prey is lured to the spider by the production of up to three sex pheromone-analogues.
Spider taxonomy is that part of taxonomy that is concerned with the science of naming, defining and classifying all spiders, members of the Araneae order of the arthropod class Arachnida with more than 48,500 described species. However, there are likely many species that have escaped the human eye to this day, and many specimens stored in collections waiting to be described and classified. It is estimated that only one third to one half of the total number of existing species have been described.
Cribellum literally means "little sieve", and in biology the term generally applies to anatomical structures in the form of tiny perforated plates.
Phyxelididae is a family of araneomorph spiders first described by Pekka T. Lehtinen in 1967 as a subfamily of Amaurobiidae, and later elevated to family status as a sister group of Titanoecidae.
The Micropholcommatinae are a subfamily of araneomorph spiders in the family Anapidae. They were previously treated as the family Micropholcommatidae. Micropholcommatins are extremely small, with body lengths typically between 0.5 and 2 mm. They are usually found among leaf litter or moss.
The Palpimanoidea or palpimanoids, also known as assassin spiders, are a group of araneomorph spiders, originally treated as a superfamily. As with many such groups, its circumscription has varied. As of September 2018, the following five families were included:
The Eresoidea or eresoids are a group of araneomorph spiders that have been treated as a superfamily. As usually circumscribed, the group contains three families: Eresidae, Hersiliidae and Oecobiidae. Studies and reviews based on morphology suggested the monophyly of the group; more recent gene-based studies have found the Eresidae and Oecobiidae to fall into different clades, placing doubt on the acceptability of the taxon. Some researchers have grouped Hersiliidae and Oecobiidae into the separate superfamily Oecobioidea, a conclusion supported in a 2017 study, which does not support Eresoidea.
Araneoidea is a taxon of araneomorph spiders, termed "araneoids", treated as a superfamily. As with many such groups, its circumscription has varied; in particular some families that had at one time been moved to the Palpimanoidea have more recently been restored to Araneoidea. A 2014 treatment includes 18 families, with the araneoids making up about 26% of the total number of known spider species; a 2016 treatment includes essentially the same taxa, but now divided into 17 families.
The Agelenoidea or agelenoids are a superfamily or informal group of entelegyne araneomorph spiders. Phylogenetic studies since 2000 have not consistently recovered such a group, with more recent studies rejecting it.
The Dictynoidea or dictynoids are a group of araneomorph spiders that have been treated as a superfamily. The composition of the group has varied. Phylogenetic studies in the 21st century have failed to confirm the monophyly of the dictynoids as originally defined.
The Haplogynae or haplogynes are one of the two main groups into which araneomorph spiders have traditionally been divided, the other being the Entelegynae. Morphological phylogenetic studies suggested that the Haplogynae formed a clade; more recent molecular phylogenetic studies refute this, although many of the ecribellate haplogynes do appear to form a clade, Synspermiata.
The Entelegynae or entelegynes are a subgroup of araneomorph spiders, the largest of the two main groups into which the araneomorphs were traditionally divided. Females have a genital plate (epigynum) and a "flow through" fertilization system; males have complex palpal bulbs. Molecular phylogenetic studies have supported the monophyly of Entelegynae.
Pinkfloydia is a genus of small Australian long-jawed orb-weavers, reaching a maximum lengths of about 4.5 millimetres (0.18 in). It was first described by D. Dimitrov & G. Hormiga in 2011, and contains two species, found in New South Wales and Western Australia: P. harveyi and P. rixi. They have a unique rounded, cone-shaped head structure with one pair of large eyes and three pairs of smaller eyes. The genus is named after British rock band Pink Floyd.
Orbiculariae is a potential clade of araneomorph spiders, uniting two groups that make orb webs. Phylogenetic analyses based on morphological characters have generally recovered this clade; analyses based on DNA have regularly concluded that the group is not monophyletic. The issue relates to the origin of orb webs: whether they evolved early in the evolutionary history of entelegyne spiders, with many groups subsequently losing the ability to make orb webs, or whether they evolved later, with fewer groups having lost this ability. As of September 2018, the weight of the evidence strongly favours the non-monophyly of "Orbiculariae" and hence the early evolution of orb webs, followed by multiple changes and losses.
The RTA clade is a clade of araneomorph spiders, united by the possession of a retrolateral tibial apophysis – a backward-facing projection on the tibia of the male pedipalp. The clade contains over 21,000 species, almost half the current total of about 46,000 known species of spider. Most of the members of the clade are wanderers and do not build webs. Despite making up approximately half of all modern spider diversity, there are no unambiguous records of the group from the Mesozoic and molecular clock evidence suggests that the group began to diversify during the Late Cretaceous.
Nephilidae is a spider family commonly referred to as golden orb-weavers. The various genera in Nephilidae were formerly placed in Tetragnathidae and Araneidae. All nephilid genera partially renew their webs.
Artifex is a small genus of orb-weaver spiders native to tropical regions of mainland Australia and to New Caledonia. The genus was erected by R. J. Kallal and Gustavo Hormiga in 2018 to contain two species moved from different genera that have several synapomorphies, including an abdomen that extends past the spinnerets, widely separated spermathecae, and dorsal markings similar to those of Zygiellinae. The name is a combination of the Latin "ars", meaning "art", and "-fex", meaning "maker" in reference to the shelters they build out of leaves.
Cyrtarachninae is a subfamily of spiders in the family Araneidae. The group has been circumscribed in several different ways. It originated as the group Cyrtarachneae, described by Eugène Simon in 1892. The group was later treated at different ranks: as a tribe, both under Simon's name and as Cyrtarachnini, and as the subfamily Cyrtarachninae. Circumscriptions have varied. The broadest circumscription, Cyrtarachninae sensu lato (s.l.), includes three of Simon's original groups, including the bolas spiders. Unlike most araneids, members of the subfamily do not construct orb webs, some not using webs at all to capture prey, some using one or more sticky drops on a single line, while others construct webs with few widely spaced non-spiral threads, some triangular. Many have been shown to attract prey by producing analogues of insect sex pheromones, particularly to attract male moths. Adult females may mimic snails, bird droppings and other objects, and so are able to remain exposed during the day time, capturing prey at night.
Gea eff is a species of orb-weaver spider. It is found in Papua New Guinea. The arachnologist Herbert Walter Levi formally described the species in 1983. While it was still undescribed, Michael H. Robinson and colleagues reported on its courtship and mating behaviors. Gea eff has the shortest scientific name of any spider species.
