''Monomorium'' is a genus of ants in the subfamily

Myrmicinae 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 ...

. As of 2013 it contains about 396 species. It is distributed around the world, with many species native to the

Old World The "Old World" is a term for Afro-Eurasia that originated in Europe , after Europeans became aware of the existence of the Americas. It is used to contrast the continents of Africa, Europe, and Asia, which were previously thought of by the ...

tropics The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

. It is considered to be "one of the more important groups of ants," considering its widespread distribution, its diversity, and its variety of morphological and biological characteristics. It also includes several familiar

pest Pest or The Pest may refer to: Science and medicine * Pest (organism), an animal or plant deemed to be detrimental to humans or human concerns ** Weed, a plant considered undesirable * Infectious disease, an illness resulting from an infection ** ...

species, such as the

pharaoh ant The pharaoh ant (''Monomorium pharaonis'') is a small (2 mm) yellow or light brown, almost transparent ant notorious for being a major indoor nuisance pest, especially in hospitals. A cryptogenic species, it has now been introduced to vi ...

(''M. pharaonis'') and the flower ant (''M. floricola'').

Description

This genus is very diverse in morphology, with species of many shapes and sizes that "do not necessarily even remotely resemble one another" at first glance. While the worker caste is monomorphic in some species, in others it is polymorphic. In some species the workers are minute, in others they are rather large. Large, multifaceted eyes are common, but ''M. inusuale'' has much reduced eyes, as do some species from Africa. The sting is always functional.Fernández, F. (2007). Two new South American species of ''Monomorium'' Mayr with taxonomic notes on the genus. ''In:'' Snelling, R. R., et al. (eds). Advances in ant systematics (Hymenoptera: Formicidae): homage to E. O. Wilson – 50 years of contributions. ''Memoirs of the American Entomological Institute'' 80, 128-45.

Taxonomy

This large genus was further expanded in 2007, when the genera ''Nothidris'', ''Epelysidris'', and ''Phacota'' were synonymized with ''Monomorium''. The small genera '' Anillomyrma'', '' Megalomyrmex'', and perhaps '' Bondroita'' should possibly also be included in ''Monomorium''. The exact boundaries of the genus are yet to be determined. It has no distinct morphological trait that sets it apart from other genera in the tribe Solenopsidini. If

cladistics Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups (" clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived char ...

were strictly applied, all Solenopsidini would be grouped in the single genus '' Solenopsis'', but the tribe lacks a strong synapomorphy. ''Monomorium'' as it currently stands is

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

, but it is used as a provisional group. Similar problems are found in the genera '' Camponotus'' and ''

Leptothorax ''Leptothorax'' is a genus of small ants with mainly Holarctic distributions. The genus is notable for its widespread social parasitism, i.e. they are dependent on the help of workers from other ant species during a part or the whole of their lif ...

''.

Biology

Most ants of this genus nest in rotting wood, under rocks, or in the soil. Some species are

scavenger Scavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a herbivorous feeding b ...

s, while others are seed collectors. Many species have

venom Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a sti ...

containing

alkaloid Alkaloids are a class of basic, naturally occurring organic compounds that contain at least one nitrogen atom. This group also includes some related compounds with neutral and even weakly acidic properties. Some synthetic compounds of similar ...

s, which they use as a defense from predators. Besides its morphological variation, the genus is also variable in

chromosome A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are ...

number, with 2''n'' of 16 to 70 recorded.

Distribution

As of 2006, 36 species are described from

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

, 19 of which were described in that year alone. About 43 species are known from

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

and 30 from

Arabia The Arabian Peninsula, (; ar, شِبْهُ الْجَزِيرَةِ الْعَرَبِيَّة, , "Arabian Peninsula" or , , "Island of the Arabs") or Arabia, is a peninsula of Western Asia, situated northeast of Africa on the Arabian Plate. ...

Selected species

* ''

Monomorium antarcticum ''Monomorium antarcticum'' is an ant of the family Formicidae, endemic to New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and ...

'' * ''

Monomorium bidentatum ''Monomorium bidentatum'' is a species of ant in the subfamily Myrmicinae. It is endemic to two South American countries, Chile and Argentina. Description Workers are around long. The general color is dark brown, with the mandibles, antennae a ...

'' * '' Monomorium chinense'' * '' Monomorium delabiei'' Fernández, 2007 * '' Monomorium dentatum'' * '' Monomorium denticulatum'' * ''

Monomorium effractor ''Monomorium effractor'' is a species of ant in the genus ''Monomorium''. It is native to India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most po ...

'' * ''

Monomorium fieldi ''Monomorium fieldi'' is an ant of the family (biology), family Formicidae, endemic (ecology), endemic to the North Island and the north of the South Island of New Zealand. It is found in a wide variety of habitats, but is very uncommon in fores ...

'' * '' Monomorium floricola'' – flower ant * '' Monomorium hospitum'' * '' Monomorium inquilinum'' * '' Monomorium inusuale'' Fernández, 2007 * '' Monomorium kondratieffi'' Sharaf & Aldawood, 2013 * '' Monomorium minimum'' – little black ant * '' Monomorium monomorium'' Bolton, 1987 * '' Monomorium noualhieri'' * '' Monomorium pergandei'' * ''

Monomorium pharaonis The pharaoh ant (''Monomorium pharaonis'') is a small (2 mm) yellow or light brown, almost transparent ant notorious for being a major indoor nuisance pest, especially in hospitals. A cryptogenic species, it has now been introduced to vi ...

'' – pharaoh ant * '' Monomorium rubriceps'' * '' Monomorium santschii'' * '' Monomorium smithi'' * '' Monomorium talbotae''

References

External links

''Monomorium''.
Japanese Ant Image Database.