''Malagidris'' is a Malagasy

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 ...

ant Ants are Eusociality, eusocial insects of the Family (biology), family Formicidae and, along with the related wasps and bees, belong to the Taxonomy (biology), order Hymenoptera. Ants evolved from Vespoidea, vespoid wasp ancestors in the Cre ...

s in the

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end botanical subfamily names with "-oideae", and zo ...

Myrmicinae Myrmicinae is a subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end botanical subfamily ...

. Described in 2014, the genus contains six

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

Species

* '' Malagidris alperti'' Bolton & Fisher, 2014 * '' Malagidris belti'' (Forel, 1895) * ''

Malagidris dulcis ''Malagidris'' is a Malagasy genus of ants in the subfamily Myrmicinae. Described in 2014, the genus contains six species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes ...

'' Bolton & Fisher, 2014 * '' Malagidris galokoa'' Bolton & Fisher, 2014 * '' Malagidris jugum'' Bolton & Fisher, 2014 * '' Malagidris sofina'' Bolton & Fisher, 2014

Taxonomy

The

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

of this genus, ''M. belti'' ( Forel, 1895), has had a moderately varied taxonomic history. It was originally described in the genus ''

Aphaenogaster ''Aphaenogaster'' is a genus of myrmicine ants in the tribe Stenammini. About 200 species have been described, including 18 fossil species. They occur worldwide except in South America south of Colombia, sub-Saharan Africa, and Antarctica. ''Ap ...

'' (

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, 1853), even though Forel remarked on its 3-segmented antennal club, rather than 4 as is usual in that genus. This character, coupled with the presence of angulate humeri and a queen with a depressed

mesosoma The mesosoma is the middle part of the body, or tagma, of arthropods whose body is composed of three parts, the other two being the prosoma and the metasoma. It bears the legs, and, in the case of winged insects, the wings. Wasps, bees and a ...

, caused Emery (1915) to exclude ''M. belti'' from ''Aphaenogaster'' and transfer it to ''Atopula'' (Emery, 1912). Forel (1917) decided that ''Atopula'' was artificial, "composed of disparate species," and established the genus ''Brunella'' to include only ''M. belti''. The component species of ''Atopula'' were later dispersed to other genera by Bolton (1976), who retained genus ''Brunella'' as its "affinities are unclear." Later however, Bolton (1982) synonymised ''Brunella'' under ''Aphaenogaster'', thus returning ''M. belti'' to its original generic combination. More extensive recent sampling of the Madagascan ant fauna has made it clear that this synonymy was incorrect. The discovery of several species referable to Forel's ''Brunella'' has allowed the diagnosis of a distinct group of Madagascan endemics, which are convergent in some characters with ''Aphaenogaster'' but certainly not

congeneric Congener may refer to: * Congener (biology), organisms within the same genus * Congener (chemistry), related chemicals, e.g., elements in the same group of the periodic table * Congener (beverages), a substance other than ethanol produced during t ...

with it. The final act of this history has been the realisation that ''Brunella'' (Forel, 1917) is the junior

homonym In linguistics, homonyms are words which are either; '' homographs''—words that mean different things, but have the same spelling (regardless of pronunciation), or '' homophones''—words that mean different things, but have the same pronunciat ...

of a

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

genus ''Brunella'' (G.W. Smith, 1909), from

Tasmania Tasmania (; palawa kani: ''Lutruwita'') is an island States and territories of Australia, state of Australia. It is located to the south of the Mainland Australia, Australian mainland, and is separated from it by the Bass Strait. The sta ...

. No replacement name was essential for ''Brunella'' (Forel, 1917) while it was a junior synonym, but after it was revived from synonymy a replacement name was necessary: ''Malagidris''.

Identification

The larger, more gracile species (e.g. ''M. alperti'', ''M. galokoa'', ''M. jugum'', ''M. sofina'') of ''Malagidris'' are remarkably convergent on the widely distributed genus ''Aphaenogaster''. However, all species of ''Malagidris'' have two critical features never exhibited by ''Aphaenogaster'' species. First, the midpoint of the anterior clypeal margin of ''Malagidris'' has a single, stout, unpaired seta. In ''Aphaenogaster'' there is always a conspicuous pair of

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 ...

, one on each side of the midpoint of the anterior clypeal margin. Second, ''Aphaenogaster'' species do not have the characteristic structure of the anteroventral peduncle of the

petiole Petiole may refer to: *Petiole (botany), the stalk of a leaf, attaching the blade to the stem *Petiole (insect anatomy) In entomology, petiole is the technical term for the narrow waist of some hymenopteran insects, especially ants, bees, and ...

. In addition to these, ''Malagidris'' always has the following: a transverse crest present on the stipes of the maxilla; a 3-segmented antennal club; a subpetiolar process present; a strongly developed sting; the anterior clypeal margin convex at the midpoint. In ''Aphaenogaster'', by contrast, the stipes usually lacks a crest (a crest is incompletely and weaky developed in a few species, strong only in '' A. relicta'', from

Haiti Haiti, officially the Republic of Haiti, is a country on the island of Hispaniola in the Caribbean Sea, east of Cuba and Jamaica, and south of the Bahamas. It occupies the western three-eighths of the island, which it shares with the Dominican ...

, which may not be properly referable to ''Aphaenogaster''), usually has a 4-segmented antennal club (5-segmented to gradually incrassate in some species but never 3-segmented), lacks a subpetiolar process, has a very weakly developed or vestigial sting, and usually (but not always) has the midpoint of the anterior clypeal margin concave or indented.

References

* * *Emery, C. (1915). "Definizione del genere Aphaenogaster e partizione di esso in sottogeneri." ''Parapheidole e Novomessor nn. gg. Rendiconto delle Sessioni della R. Accademia delle Scienze dell'Istituto di Bologna'' (N.S.), 19: 67–75 * * {{Taxonbar, from=Q17107691 Myrmicinae Ant genera Hymenoptera of Africa Insects of Madagascar Endemic fauna of Madagascar Taxa named by Barry Bolton