Lordomyrma

Taylor, Robert W., 2009, Ants of the genus Lordomyrma Emery (1) Generic synonymy, composition and distribution, with notes on Ancyridris Wheeler and Cyphoidris Weber (Hymenoptera: Formicidae: Myrmicinae), Zootaxa 1979, pp. 16-28 : 21-23

The Lordomyrma fauna of New Caledonia

The main Island of New Caledonia is estimated to cover 6, 223 sq.mi., or c. 16, 110 sq.km ( Robson, 1963). The ANIC, Institut de Recherche pour le Développement (Noumea) and Queensland Museum collections contain over 25, sometimes bizarre Lordomyrma species. Only three of which have been scientifically named, and they were first assigned to separate genera. Considering the small size of the island this fauna is very species-rich and spectacularly morphologically diverse. This is arguably the world's most impressive known formicid species flock.

L. caledonica was assigned from Podomyrma to Lordomyrma when the genus was established by Emery (1897). Its general attributes ( Figs 13, 14 ) relate appropriately to those of L. furcifera ( Figs 7, 8 ). L. sarasini (Figs 15, 16) and L. rouxi (Figs 17, 18) were described by Emery in 1911 as type species respectively of the seemingly distinctive and strikingly aberrant new monotypic genera Prodicroaspis and Promeranoplus , now synonymised under Lordomyrma . They are the only ant genera recently considered endemic to New Caledonia.

The synonymies of Prodicroaspis and Promeranoplus are justified in light of the extreme morphological diversity seen among the undescribed New Caledonian Lordomyrma species. Their type species and L. caledonica are linked by other species to more conservative taxa with habitus similar to that of the Australian punctiventris group. Also, several other highly aberrant, clearly congeneric, apparently separately derived but linked Lordomyrma species are represented on New Caledonia. Details will be presented elsewhere. Nine investigated New Caledonian species have the palpal formula 3:3, one has 3:2.

Most of these taxa are represented by limited material and it is unlikely that New Caledonian Lordomyrma species-numeric or morphological diversity is well represented. Even now, however, there is on average 1 known Lordomyrma species for approximately each 280 sq.mi. (c. 16.8 mi2), or 730 sq.km.(27 km 2) of New Caledonian mainland. If study of these ants is to yield information of maximum value to the understanding of their evolutionary proliferation, detailed biogeographic data must be gathered before habitat modification or destruction further disrupts the natural species-distribution patterns. The potential scientific importance of the New Caledonian Lordomyrma fauna in a world of diminishing nature cannot be overestimated!

Lordomyrma is not the only significant, unusually species-rich and morphologically disparate formicid genus known from the biologically very special, but environmentally threatened, island of New Caledonia. Indeed, the taxonomic analysis and evolutionary investigation of the whole New Caledonian ant fauna deserves high scientific priority.

Other significant myrmicine genera include Monomorium (= Chelaner ) and Vollenhovia . The ponerine genus Discothyrea is known from its representation in the ANIC to comprise more species on New Caledonia than are known from all of Australia, including taxa perhaps as divergent within the genus as those of any continent (even though only one species has been described). The known New Caledonian Rhytidoponera species have been reviewed by Ward (1984). With 18 somewhat morphologically disparate taxa this fauna is more species-rich than that of perhaps any comparable land area of Australia, where Rhytidoponera is overall the most prominent and species-rich ponerine ant genus.

Rhytidoponera is the most comprehensively known New Caledonian ant genus, yet 11 of its 18 known valid species were unnamed until described by Ward in 1984 (and most of them were first collected by him only shortly before). The remaining 7 species were described in 1839, 1883 (2 species), 1914, 1924 and 1958 (2 species).

The priority for research on New Caledonian ants is now urgent, considering the presence on the island of the myrmecologically super-dominant introduced Central American myrmicine ‘Little Fire Ant’ Wasmannia auropunctata , which has the potential to violently disrupt local ant faunas and to eradicate other ants, insects and higher animals from its domain. Wasmannia has been present for at least 30 years and was already widespread when first reported ( Fabres & Brown, 1978). Modern records show it now to be almost ubiquitous on New Caledonia.

Figures

FIGURES 13, 14. Lordomyrma caledonica, New Caledonica, HW 1.06 mm, WL 1.61 mm. FIGURES 15, 16. Lordomyrma sarasini, New Caledonica, HW 1.01 mm, WL 1.42 mm. FIGURES 17, 18. Lordomyrma rouxi, New Caledonica, HW 1.68 mm, WL 2.01 mm.

FIGURES 7, 8. Lordomyrma furcifera, Papua New Guinea, HW 0.89 mm, WL 1.32 mm. FIGURES 9, 10. Lordomyrma infundibuli, West Papua, HW 0.99 mm, WL 1.36 mm.