Monomorium

Monomorium Mayr

Monomorium Mayr, 1855: 452. Type-species: Monomorium monomorium Bolton, 1987: 287.

Phacota Roger, 1862: 260. Type species: Phacota sichelli Roger, 1862: 262. Synonym of Monomorium: Ettershank, 1966: 82. Genus revalidated: Bolton, 1987: 281. Syn. rev.

Nothidris Ettershank, 1966: 105. Type-species: Monomorium latastei Emery, 1895: 10. Syn. n.

Antichthonidris Snelling, 1975: 5. Type-species: Monomorium denticulatum Mayr, 1887: 614. Junior synonym of Monomorium: Heterick, 2001: 361.

Epelysidris Bolton, 1987: 279. Type-species: Epelysidris brocha Bolton, 1987: 280. Syn. n.

For a full list of synonymies before Heterick (2001) see Bolton (1987: 287 - 288).

WORKER DIAGNOSIS (after Bolton, 1987: 289; Heterick, 2001: 363 - 364).

Monomorphic to polymorphic. Minute to moderately large in total length. Mandibles with 4 to 5 teeth. Maxillary palps with 2 to 4 segments. Median clypeal seta present, sometimes displaced or absent. Median portion of clypeus raised, longitudinally bicarinate, the carinae rarely effaced. Frontal carinae absent past frontal lobes. Antennal scrobes absent. Antennae with 11 - 12 segments and with club of 3 (rarely 4) segments. Eyes present, sometimes reduced. Metapleural glands never bulging or hypertrophied. Metapleural lobes usually small, rounded. Propodeum normally unarmed, sometimes angulated to dentate, rarely with lamelliform process. Propodeal spiracle usually circular and at about midlength of the sclerite, rarely in another position. Petiole pedunculated, the petiolar spiracle usually close to or at node. Sting functional.

Nothidris was created by Ettershank (1966) and further delimited by Snelling (1975), who created Antichthonidris to accomodate some species. Bolton (1987: 284 - 285) discussed the traits proposed for the latter, demonstrating their weakness and dubious value as generic-level characters: a vestibulated propodeal spiracle appears to be present in some Australian Monomorium species (Bolton, 1987), for instance, as well as in M. delabiei. Moreover, the inclusion of Antichthonidris in Monomorium, as proposed by Heterick (2001), leaves no justification for maintaining Nothidris as a separate genus.

Phacota has been a taxonomic problem in the myrmicines, due to its poor description, the disappearance of the type specimen, and the lack of collected material referable to P. sichelii (Bolton, 1987), all of which have impeded an evaluation of its taxonomic status. Ettershank (1966) considered this name a junior synonym of Monomorium. Bolton (1987) subsequently revived the genus, citing the few attributes that can be retrieved from Roger's (1862) original description; nevertheless, he made explicit his strong suspicion that the putative species is based on a wingless, ergatoid Monomorium female, perhaps from the M. salomonis group. Both the meager description (e. g., that the gaster is bigger than the head) and the important fact that the species has not been rediscovered in Spain or any other nearby location, are consistent with this interpretation. Given that the European ant fauna can be considered acceptably collected and studied, and in light of the group's importance, samples assignable to Phacota would surely have been detected and described by now. According to its description, Phacota is characterized by 11 - segmented antennae with a 2 - segmented club. Some Neotropical Solenopsis females possess this combination, but it is an antennal configuration unknown in Monomorium, and it is highly probable that the description of the number of flagellomeres in the antenna and club is erroneous. It would not be the only inadvertent mistake of this type in the history of ant systematics, especially given the size of the ants and the optical resolution possible in the 19 th century. It seems of little practical use to maintain a badlydescribed genus, with no associated type material, and no other collected material, and I recommend that Phacota once again be demoted as proposed by Ettershank (1966) until and unless more material is discovered, or the type specimen (in good condition) reappears.

Epelysidris is a monotypic genus of eastern Malaysia, easily separable by the distinctive pair of lobules on the basal border of each mandible, mandibular and clypeal structure, and palpal formula (Bolton, 1987). Although this taxon is undoubtedly monophyletic, its continued recognition as a separate genus would create the same dilemmas that characterize Antichthonidris, Nothidris, and some others. It is preferable to leave brocha as one additional (although highly apomorphic) species within Monomorium; I propose here that Epelysidris thus be considered a junior synonym of Monomorium.

Neotropical species of Monomorium (includes recent introductions *).

M. bidentatum Mayr, 1887 comb. rev. – Chile, Argentina

M. brasiliense Forel, 1908 - Brazil

M. carbonarium Fr. Smith, 1858 – Azores

M. cekalovici (Snelling, 1975) comb. nov. - Chile

M. chilensis, n. name for N. bicolor Ettershank, 1965: 55, preoccupied by M. bicolor Emery, 1877: 368 - Chile

M. cyaneum Wheeler, 1914 - Mexico

M. compressum Wheeler, 1914 – Mexico

M. delabiei sp. n. - Brazil

M. denticulatum Mayr, 1887 comb. rev. – Chile, Argentina

M. destructor (Jerdon, 1852) * - Widespread

M. ebeninum Forel, 1891 – Caribbean and coastal Mesoamerica

M. floricola (Jerdon, 1852) * - Widespread

M. inquilinum DuBois, 1980 - Mexico

M. inusuale sp. n. - Brazil

M. latastei Emery, 1895 comb. rev. - Chile

M. marjoriae DuBois, 1986 – Mexico

M. minimum (Buckley, 1867) – Mexico (?) Paraguay (?)

M. monomorium Bolton, 1987 * – Barbados

M. pharaonis (Linnaeus, 1758) * - Widespread

M. salomonis (Linnaeus, 1758) * - Widespread

M. subcoecum Emery, 1894 – Caribbean (St. Thomas and Puerto Rico)

M. subopacum Fr. Smith, 1858 * – Antigua

Outside the Neotropical fauna the following changes are proposed:

Monomorium sichelii (Roger, 1862) comb. rev.

Monomorium brocha (Bolton, 1987) comb. n.