Frilled orbweavers | |
---|---|
Kaira alba | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Subphylum: | Chelicerata |
Class: | Arachnida |
Order: | Araneae |
Infraorder: | Araneomorphae |
Family: | Araneidae |
Genus: | Kaira O. Pickard-Cambridge, 1889 [1] |
Type species | |
K. gibberosa O. Pickard-Cambridge, 1890 | |
Species | |
16, see text | |
Synonyms [1] | |
Kaira, sometimes called frilled orbweavers, [3] is a mostly neotropical genus of orb-weaver spiders first described by O. Pickard-Cambridge in 1889. [4] It includes sixteen described species that occur from South America up to the southern and eastern USA. [1] It is presumably related to Aculepeira , Amazonepeira and Metepeira . [5]
They spin small webs from which they hang upside down and attract male moths that fly into a basket formed by their legs. They use a moth pheromone for this, which resembles the one used by the bolas spiders of the genus Mastophora . Though they belong to the same family, the two genera are not closely related, so this is likely an example of convergent evolution. [5]
All species are pale yellow-white with scattered, small, white, brown and black random spots, or in some species transverse bands. Females have a body length of about 4 to 10 millimetres (0.16 to 0.39 in). Males are less than half the size of females and less pigmented. [5]
Kaira specimens are uncommon in arachnologist collections, and the females of different species are difficult to separate. Females and immatures can be confused with species of the not closely related genus Pozonia . [5]
When a fly was put into a jar containing a K. alba, the female dropped from the underside of the lid on what seemed a single thread about 12 mm (0.47 in) long and hung there until the fly blundered into her. Then she clamped her legs around it and killed it. Instead of constructing orb webs, they construct a small trapezoidal web, containing two triangular zigzags of threads, which is remade every twenty minutes. The spider then hangs upside-down by the fourth leg on the lower and shorter parallel edge of the trapezoid, which is spread by the other legs. When a moth flies into the basket formed by the spider's legs, it is clasped and bitten, and later wrapped in araneid-like fashion. The moth is then hung from a trapeze line between the last legs of the spider, which resumes the hunting posture. As many as eight moths can be caught in this way before the spider starts feeding. [5]
As of April 2019 [update] it contains sixteen species: [1]
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.
Eriophora is a genus of orb-weaver spiders first described by Eugène Simon in 1895. It occurs in the Americas and Africa. The name is derived from Ancient Greek roots, and means "wool bearing".
Aculepeira ceropegia, the oak spider, is an orb-weaving spider species belonging to the family Araneidae.
Aculepeira is a genus of orb-weaver spiders first described by R. V. Chamberlin & Wilton Ivie in 1942.
Ordgarius is a genus of orb-weaver spiders first described by Eugen von Keyserling in 1886. Adult females of the genus are bolas spiders, capturing their prey with one or more sticky drops at the end of a single line of silk rather than in a web. Males and juvenile females capture their prey directly with their legs.
Micrathena, known as spiny orbweavers, is a genus of orb-weaver spiders first described by Carl Jakob Sundevall in 1833. Micrathena contains more than a hundred species, most of them Neotropical woodland-dwelling species. The name is derived from the Greek "micro", meaning "small", and the goddess Athena.
Dolichognatha is a genus of tropical and subtropical long-jawed orb-weavers that was first described by Octavius Pickard-Cambridge in 1869. Originally placed with the Archaeidae, it was transferred to the Araneidae in 1967, and to the Tetragnathidae in 1981.
Acacesia is a genus of orb-weaver spiders first described by Eugène Simon in 1895. It contains six species with a mostly neotropical distribution, ranging from South America to Mexico. One species, A. hamata, is found in the US as well.
Metepeira is a genus of orb-weaver spiders first described by F. O. Pickard-Cambridge in 1903. The name is derived from the Ancient Greek μετά and the obsolete genus name Epeira, denoting a genus similar to Epeira.
Glenognatha is a genus of long-jawed orb-weavers that was first described by Eugène Louis Simon in 1887. It was considerably revised in 2016.
Mastophora, also known as bolas spiders, is a genus of orb-weaver spiders first described by E. L. Holmberg in 1876. They can be identified by a pair of lumps on the dorsal surface of the opisthosoma, though not all males will have these lumps.
Parawixia is a genus of orb-weaver spiders first described by F. O. Pickard-Cambridge in 1904. Most species are found in the Neotropics but one species, Parawixia dehaani, is found in Australasia and tropical Asia as far west as India.
Allocyclosa is a genus of orb weaver spiders that contains only one species, Allocyclosa bifurca. It was first described in 1887 by McCook under the name Cyrtophora bifurca, and was transferred to its own genus in 1999. It is the only Cyclosa species north of Mexico to have a forked rear tip of the abdomen hence the name bifurca, Latin for "two-pronged". The forked tip of the abdomen, bearing two humps shaped like the letter M, is a defining feature in both males and females, though it is similar to features present in certain Cyrtophora species. Both sexes are a grey-green color, though only females have an area of red on their underside between the epigynum and the spinnerets. Females are much larger than males, ranging from five to nine millimeters, while males range from two to three millimeters. Males appear to be very uncommon, but they are probably often overlooked by collectors due to their small size. In a 1977 study by Levi, only two of the nearly 350 specimens that were positively identified as Cyrtophora bifurca were males. This is a very unusual distribution; a second, less likely explanation that has been proposed is that females of the species, which have less prominent genitalia compared with those of other members of the orb-weaver family, may be parthenogenic, are able to reproduce without the help of males. Like most other members of Araneidae, these spiders build orb webs, six to eight inches in diameter, but employ an unusual form of protective mimicry. Females often sit in the middle of a vertical row of web decoration that include egg sacs and wrapped prey. Because the spider and the egg sacs have a similar color and shape, it is difficult to distinguish the egg sacs from the spider itself.
Cladomelea is a genus of African orb-weaver spiders first described by Eugène Simon in 1895. Adult females of the genus are bolas spiders, capturing their prey with one or more sticky drops at the end of a single line of silk rather than in a web. Males and juvenile females capture their prey directly with their legs.
Kapogea is a genus of orb-weaver spiders first described by Herbert Walter Levi in 1997.
Metazygia is a genus of orb-weaver spiders first described by F. O. Pickard-Cambridge in 1904. They physically resemble members of Nuctenea, but they do not have fine setae on the carapace.
Wagneriana is a genus of orb-weaver spiders first described by F. O. Pickard-Cambridge in 1904.
Azilia is a genus of long-jawed orb-weavers that was first described by Eugen von Keyserling in 1881. It is a senior synonym of Cardimia.