Myrmeciinae

These large, conspicuous ants are only found in Australia and New Zealand. In Australia they are most abundant and diverse in the southern regions and rare in the tropics.

The subfamily contains two genera (with three additional genera known only from fossils): Myrmecia with its 89 described species and subspecies are limited to Australia and New Caledonia while Nothomyrmecia with a single species is restricted to mallee of southern Australia. Species of Myrmecia are often abundant and can be found in a range of habitats including parks and gardens while Nothomyrmecia are rarely encountered although it appears that they are more common and widespread than the known material would suggest. This is largely because of their inconspicuous nests and cryptic foraging behaviour.

Identification
This subfamily contains two highly distinctive genera, Myrmecia and Nothomyrmecia. Myrmecia have long, straight mandibles, large eyes and often bright colours. Nothomyrmecia can be recognised by their pale yellow colour, large eyes, elongate mandibles, lack of a postpetiole and the presence of a sting. These genera are unlikely to be confused with any other Australian ant.

Heterick (2009) - Members of this subfamily are now placed in two tribes. The tribe Myrmeciini contains the well-known bulldog ants. These ants are easily recognised by their combination of slightly curved, elongate mandibles with at least vestigial teeth on the inner margin, two distinct waist segments, and large eyes placed very near the mandibular insertions.

The monotypic tribe Prionomyrmecini contains one extant genus and species Nothomyrmecia macrops, though the tribe is more diverse in the fossil record. Nothomyrmecia macrops is superficially similar to bulldog ants. However, there is only one waist segment, the eyes are well separated from the mandibular insertions and the mandibles themselves have more than 15 intermeshing teeth.

Males: Boudinot (2015) - Uniquely identified by the combination of petiolation of abdominal segment III (Myrmeciini), retention of the jugal lobe and of two ventroapical spurs on each meso- and metatibia, and complete fusion of the petiolar tergum and sternum anteriorly (Prionomyrmecini). The third abdominal segment of the male of Nothomyrmecia (Prionomyrmecini) is incompletely petiolated, although it is still recognizable by the other states indicated above.

Nomenclature
MYRMECIINAE [subfamily of Formicidae]
 * Myrmeciidae Emery, 1877a: 71 [as "group" of Myrmicidae]. Type-genus: Myrmecia.
 * Myrmecii: Forel, 1893a: 162 [as tribe of Ponerinae].
 * Myrmeciinae: Ashmead, 1905b: 382 [as subfamily of Poneridae].
 * Myrmeciinae: Clark, 1951: 17 (in key) [as subfamily of Formicidae].

Bolton 2003:

The myrmeciomorph subfamilies

Subfamilies Myrmeciinae, Pseudomyrmecinae.

Diagnosis Antennal sockets inclined upward toward midline of head (note 1). Sensilla basiconica of antenna with socket raised above the cuticular sUiface. Promesonotal suture present and flexible, the pronotum and mesonotum capable of movement relative to each other (note 2). Metanotum present on dorsal ali trunk. Metapleural gland orifice not concealed by a broad cuticular flange or flap. Propodeal lobes present (note 3). Metabasitarsal sulcus present (note 4). Metatibia with 2 spurs, posterior spur largest and usually pectinate (note 5). Pretarsal claws each with a preapical tooth on the inner margin (note 6). Petiole without tergosternal fusion. Helcium sternite small and retracted, overlapped by the tergite. Waist of one or two segments but abdominal segment III always smaller than IV. Abdominal segments III and IV without tergosternal fusion (also in male). Spiracles of abdominal segments V - VII concealed by posterior margins of preceding tergites. Sting present, usually strongly developed. [Synopsis, p. 131.]

Notes (1) For distribution of character see notes under formicomorph subfamilies. (2) For distribution of character see notes under myrmicomorph subfamilies. (3) Propodea1lobes are absent in the leptanillomorphs, present in the myrmeciomorphs and poneromorphs, variously absent or present in the dorylomorph subfamilies. In myrmicomorphs propodea1 lobes are absent in Melissotarsini and Crematogaster, reduced to narrow carinae or absent in Myrmicaria; in formicomorphs they are present only in Oecophylla. (4) The metabasitarsal sulcus is secondarily absent from Pseudomyrmex (Pseudomyrmecinae); a similar sulcus appears in the poneromorph genus Paraponera (Paraponerini), presumably convergently. (5) Posterior metatibial spur is spiniform and not pectinate only in the Myrmecia cephalotes species group. (6) The preapical tooth of the pretarsal claw is reduced or absent in a few small Tetraponera species.

MYRMECIINAE

Diagnosis With characters of myrmeciomorph subfamilies. Mandible multidentate and elongate. Median portion of clypeus short but posteriorly extended back between the antennal sockets. Eyes large and prominent. Metapleural gland orifice relatively widely separated from ventral margin of metapleuron. Orifice of propodeal spiracle slit-shaped. Metacoxal cavities open. Sting bulb gland present (note 2). Jugal lobe present on hindwing of alates (note 1). Palp formula 6,4. Antenna filiform, with 12 segments (13 in male and with very short stout scape). [Synopsis, p. 131.]

Notes (1) Jugal lobe of the hindwing is also present in a number of poneromorphs which, as a whole, are highly polymorphic for this character. The jugal lobe is universally absent in Pseudomyrmecinae, the dorylomorph, formicomorph and myrmicomorph subfamilies, and Leptanillini; its absence is regarded as the apomorphic condition. (2) In extant genera, not confirmed in *Prionomyrmex.