''Micrathena'', known as spiny orbweavers, is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of orb-weaver spiders first described by

Carl Jakob Sundevall Carl Jakob Sundevall (22 October 1801 in Högestad – 2 February 1875) was a Sweden, Swedish zoologist. Sundevall studied at Lund University, where he received a Ph.D. in 1823. After traveling to East Asia, he studied medicine, graduating as a ...

in 1833. ''Micrathena'' contains more than a hundred species, most of them

Neotropical The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In biogeogra ...

woodland-dwelling species. The name is derived from the Greek "micro", meaning "small", and the goddess

Athena Athena or Athene, often given the epithet Pallas, is an ancient Greek religion, ancient Greek goddess associated with wisdom, warfare, and handicraft who was later syncretism, syncretized with the Roman goddess Minerva. Athena was regarde ...

. Species with extremely long spines evolved at least eight times in the genus ''Micrathena'' and likely function as anti-predator defenses. ''

Gasteracantha ''Gasteracantha'' is a genus of orb-weaver spiders first named by Carl Jakob Sundevall in 1833. Species of the genus are known as spiny-backed orb-weavers, spiny orb-weavers, or spiny spiders. The females of most species are brightly colored wi ...

'' orb-weavers also have hardened abdomens with variously shaped spines, but they are not closely related to ''Micrathena'' within the orb-weaver family. These spiders are active during the daytime and build vertical orb webs. Unlike many other orb-weavers, members of ''Micrathena'' bite their prey before wrapping it. When laying eggs, females will place the egg sac on vegetation near the web.

Species

the genus ''Micrathena'' contains 119 species:

In North America

Although the genus includes over a hundred species, only four are found in the United States and Canada. Among those four species, female spined micrathena ('' Micrathena gracilis'') have five pairs of conical

tubercle In anatomy, a tubercle (literally 'small tuber', Latin for 'lump') is any round nodule, small eminence, or warty outgrowth found on external or internal organs of a plant or an animal. In plants A tubercle is generally a wart-like projectio ...

s, female '' M. mitrata'' have two short posterior pairs, and female arrow-shaped micrathena ('' M. sagittata'') have three pairs. Only two species are recorded from Canada, being ''M. sagittata'', found primarily in the Pinery Provincial Park, and ''M. gracilis'', which is more widespread.

References

{{Authority control Araneidae Araneidae genera