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

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of orb-weaver spiders first described by

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

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 bioge ...

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 goddess associated with wisdom, warfare, and handicraft who was later syncretized with the Roman goddess Minerva. Athena was regarded as the patron and protectress of ...

. 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 ''Micrathena gracilis'' is a spider in the family Araneidae (orb-weavers), commonly known as the spined micrathena or castleback orbweaver. This spider spins a moderately large (can be about 20 cm long in diameter) and very tightly coiled w ...

'') 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 projection ...

s, female '' M. mitrata'' have two short posterior pairs, and female arrow-shaped micrathena ('' M. sagittata'') have three pairs. The only species recorded from Canada is ''M. sagittata'', found in

Ontario Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central Ca ...

References

{{Taxonbar, from=Q1165225 Araneidae Araneidae genera