Myrma

The subgenus Myrma Billberg is the most widespread of all the Polyrhachis subgenera, occurring throughout the Indo-Malayan, Oriental, Australasian and Ethiopian regions. It is also the second most speciose subgenus, comprising more than one hundred described species and subspecific forms. (Kohout 2013)

Nomenclature

 *  MYRMA [subgenus of Polyrhachis]
 * Myrma Billberg, 1820: 104. Type-species: Formica militaris, by subsequent designation of Wheeler, W.M. 1911c: 859.
 * Myrma subgenus of Polyrhachis: Forel, 1915b: 106; Forel, 1917: 251; Wheeler, W.M. 1922a: 702, 993; Emery, 1925b: 198.
 * Myrma senior synonym of Hoplomyrmus: Wheeler, W.M. 1922a: 993.
 * Myrma senior synonym of Pseudocyrtomyrma: Bolton, 1973b: 288.
 * Myrma senior synonym of Anoplomyrma: Dorow, 1995: 30.
 * [Although Myrma antedates Polyrhachis, the former has been treated as a subgenus of the latter since Forel, 1917: 251 (see Hung, 1967b: 396 for history). Dorow, Kohout & Taylor, 1997: 236 proposed the precedence of Polyrhachis over Myrma and that precedence was established by the ICZN (Opinion 1919) 1999: 92.]
 * ANOPLOMYRMA [junior synonym of Myrma]
 * Anoplomyrma Chapman, 1963: 258 [as subgenus of Polyrhachis]. Type-species: Polyrhachis (Anoplomyrma) parabiotica, by monotypy.
 * Anoplomyrma junior synonym of Myrma: Dorow, 1995: 30.
 * HOPLOMYRMUS [junior synonym of Myrma]
 * Hoplomyrmus Gerstäcker, 1859: 262. Type-species: Hoplomyrmus schistaceus, by monotypy.
 * [Hoplomyrmus also described as new by Gerstäcker, 1862: 508.]
 * Hoplomyrmus junior synonym of Polyrhachis: Roger, 1861b: 174; Roger, 1863b: 6; Mayr, 1863: 446; Dalla Torre, 1893: 257.
 * Hoplomyrmus junior synonym of Myrma: Wheeler, W.M. 1922a: 993; Emery, 1925b: 198; Bolton, 1973b: 288.
 * PSEUDOCYRTOMYRMA [junior synonym of Myrma]
 * Pseudocyrtomyrma Emery, 1921e: 18 [as subgenus of Polyrhachis]. Type-species: Polyrhachis revoili, by original designation.
 * Pseudocyrtomyrma junior synonym of Myrma: Bolton, 1973b: 288.

Description
Kohout (1989) – The subgenus Myrma Billberg can be characterised by the following combination of characters:

1. Dorsum of mesosoma convex in profile; lateral margins distinct, with margination interrupted only at the sutures.

2. Pronotum armed with a pair of relatively long, straight, more or less anteriorly-directed spines.

3. Propodeum either unarmed or with tubercles or small teeth.

4. Promesonotal suture and propodeal groove distinct.

5. Petiole scale-like, usually armed with a pair of dorsal spines or denticles, each with a laterally oriented tooth or blunt angle below its base.

6. First gastral tergite basally truncated or shallowly concave.

7. Anterior clypeal margin arcuate, often bluntly truncated medially.

8. Mandibles at their bases finely longitudinally striate.

9. Frontal carinae forming sharply raised, lamellate flanges; the area between them relatively narrow.