''Castianeira'' 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 ant-like corinnid sac spiders first described by

Eugen von Keyserling Eugen von Keyserling (22 March 1833 in Pockroy, Lithuania – 4 April 1889 in Dzierżoniów, Silesia Silesia (see names #Etymology, below) is a historical region of Central Europe that lies mostly within Poland, with small parts in the Czec ...

in 1879. They are found in

Eurasia Eurasia ( , ) is a continental area on Earth, comprising all of Europe and Asia. According to some geographers, Physical geography, physiographically, Eurasia is a single supercontinent. The concept of Europe and Asia as distinct continents d ...

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

, and the

Americas The Americas, sometimes collectively called America, are a landmass comprising the totality of North America and South America.''Webster's New World College Dictionary'', 2010 by Wiley Publishing, Inc., Cleveland, Ohio. When viewed as a sing ...

, but are absent from

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

. Twenty-six species are native to North America, and at least twice as many are native to Mexico and Central America.

Description

Spiders of this genus have eight eyes in two procurved rows (meaning that the lateral eyes are farther toward the front of the body than the medial eyes), the upper row slightly wider than the lower row. This distinguishes them from species of ''

Micaria ''Micaria'' is a genus of Gnaphosidae, ground spiders that was first described by Niklas Westring in 1851. They are long. They are often called "ant spiders" due to their ant-like appearance and ant mimicry, ant mimicking behavior. Species it ...

'' that almost always have straight rows of eyes. The

opisthosoma The opisthosoma is the posterior part of the body in some arthropods, behind the prosoma ( cephalothorax). It is a distinctive feature of the subphylum Chelicerata (arachnids, horseshoe crabs and others). Although it is similar in most respects ...

is not constricted, and has an elongate to oval shape to mimic that of ants. In addition to the ant-like coloration, the abdomen has white scale-like

setae In biology, setae (; seta ; ) are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Depending partly on their form and function, protostome setae may be called macrotrichia, chaetae ...

. The rear pair of legs are the longest, and the front pair are second longest.

Mimicry

Some species are ant mimics resembling specific groups of ants, while others only have generic body modifications to look more ant-like, such as an elongated body or a carapace pattern that creates the illusion of a third body segment. Some mimic ant behavior as well, waving their front two legs as if they were antennae or bobbing their abdomen to look more ant-like. Certain species found in Texas mimic

fire ant Fire ants are several species of ants in the genus ''Solenopsis'', which includes over 200 species. ''Solenopsis'' are stinging ants, and most of their common names reflect this, for example, ginger ants and tropical fire ants. Many of the nam ...

s to prey on them, while some species use

Batesian mimicry Batesian mimicry is a form of mimicry where a harmless species has evolved to imitate the warning signals of a harmful species directed at a predator of them both. It is named after the English naturalist Henry Walter Bates, who worked on butt ...

, appearing like velvet ants to take advantage of their

aposematism Aposematism is the Advertising in biology, advertising by an animal, whether terrestrial or marine, to potential predation, predators that it is not worth attacking or eating. This unprofitability may consist of any defenses which make the pr ...

in order to deter predators.

Ant mimicry

Known ant-spider mimicry: *''

Castianeira cingulata ''Castianeira cingulata'', the twobanded antmimic, is a species of true spider in the family Corinnidae Corinnidae is a family of araneomorph spiders, sometimes called corinnid sac spiders. The family, like other "clubionoid" families, has a ...

'' – short carpenter ants *''

Castianeira longipalpa ''Castianeira longipalpa'' is an Ant mimicry, ant mimic spider species in the family Corinnidae. They can be dark grey, brown or black and possess numerous transverse bands on their abdomen. Females are 7–9 mm long and males are 5.5–6&n ...

'' –

myrmicine Myrmicinae is a subfamily of ants, with about 140 extant genera; their distribution is cosmopolitan. The pupae lack cocoons. Some species retain a functional sting. The petioles of Myrmicinae consist of two nodes. The nests are permanent and ...

ponerine Ponerinae, the ponerine ants, is a subfamily of ants in the Poneromorph subfamilies group, with about 1,600 species in 47 extant genera, including ''Dinoponera gigantea'' - one of the world's largest species of ant. Mated workers have replaced ...

ants *''

Castianeira memnonia ''Castianeira'' is a genus of ant-like corinnid sac spiders first described by Eugen von Keyserling in 1879. They are found in Eurasia, Africa, and the Americas, but are absent from Australia. Twenty-six species are native to North America, and ...

'' – ''

Pachycondyla ''Pachycondyla'' is a Ponerinae, ponerine genus of ants found in the Neotropics. Distribution ''Pachycondyla'' is currently distributed from southern United States to northern Argentina, but some fossil species (e.g. ''Pachycondyla eocenica, P. ...

obscuricornis'' Emery *''

Castianeira rica ''Castianeira'' is a genus of ant-like corinnid sac spiders first described by Eugen von Keyserling in 1879. They are found in Eurasia, Africa, and the Americas, but are absent from Australia. Twenty-six species are native to North America, and ...

'' – ''

Atta Atta or ATTA may refer to: * ''Atta'' (ant), a genus of ants * ''Atta'' (novel), a 1953 novel by Francis Rufus Bellamy * Atta flour, whole wheat flour made from durum wheat commonly used in South Asian cooking * Atta (Buddhism) or Ātman, Pali f ...

'' sp, ''

Odontomachus ''Odontomachus'' is a genus of ants commonly called trap-jaw ants found in the tropics and subtropics throughout the world. Overview Commonly known as trap-jaw ants, species in ''Odontomachus'' have a pair of large, straight mandible (insect) ...

'' sp, and others *''

Castianeira trilineata ''Castianeira trilineata'' is a species of true spider in the family Corinnidae. It is an ant mimic found in the United States and Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and ...

'' – reddish carpenter ants ( Latreille)

Species

it contains 127 species:

Description

Mimicry

Ant mimicry

Species

References

Further reading