Lordomyrma

Taylor, R. 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 : 16-24

Generic synonymy

Lordomyrma Emery, 1897: 591. Type species (designated by Wheeler, 1911): L. furcifera Emery , 1897: 591 (Lemien, PAPUA NEW GUINEA).

= Prodicroaspis Emery , 1914: 414. Type species (by monotypy): P. sarasini Emery , 1914: 414 (Mt Ignambi, NEW CALEDONIA). (Junior Synonym of Lordomyrma , Bolton, 1994: 106).

= Promeranoplus Emery, 1914: 412. Type species (by monotypy): P rouxi Emery , 1914: 413 (Tchalabel, NEW CALEDONIA). (Junior synonym of Lordomyrma , Bolton, 1994: 106).

Junior synonymy of Prodicroaspis and Promeranoplus was anticipated by Holldobler & Wilson (1990: 110). Taxonomic history is summarized by Bolton (2003: 204). The above synonymy is justified below in notes on the New Caledonian fauna. The type species of Prodicroaspis and Promeranoplus relate readily to L. furcifera (Figs 7, 8; 13-16), the type species of Lordomyrma , through bridging taxa with characters intermediate in either expression or combination, so that all may reasonably be considered congeneric.

Lordomyrma includes several more-or-less geographically separated Indo-Australian faunas, which appear to represent the products of separate congeneric evolutionary radiations. The faunas of SE Asia and Japan, Australia, lowland New Guinea and the Solomon Islands, New Caledonia, and Fiji differ distinctively in relative known species richness, in the apparent frequency of sympatric associations (and presumably of resulting interspecific competitive encounters), and in levels of interspecific morphological diversity. They are discussed below under individual headings. No fauna, except perhaps those of Australia and Fiji, can be considered well represented in collections.

Generic diagnosis

Lordomyrma is assigned to tribe Stenammini , as diagnosed by Bolton (2003: 58). It is characterized by 12- merous antennae, a simple sting with straight apex, triangular mandibles with seven or more teeth decreasing in size from apex to base, well-developed propodeal spines, a bicarinate clypeus and elongate frontal carinae. Some of these characters will be reassessed in the series of papers projected here.

Checklist of named Lordomyrma species

The following list includes all known described species referable to Lordomyrma as delimited here.

L. accuminata Stitz , 1912: 504; NEW GUINEA ( L. cryptocera accuminata ). NEW STATUS.

L. azumai (Santschi) , 1941: 3, fig. 3; Minoo, Osaka, JAPAN ( Rogeria (Rogeria) azumai ) (Combination: Brown, 1952: 124).

= nobilis Yasumatsu , 1950: 75; Mt Hikosan, Kyushu, JAPAN (Synonymy: Brown, 1952: 124).

L. bensoni Donisthorpe : see L. furcifera .

L. caledonica (Andre) , 1889: 225; Noumea, NEW CALEDONIA ( Podomyrma caledonica ) (Combination: Emery, 1897: 591).

L. crawleyi Menozzi , 1923: 209, fig. 1; Humboldt Bay, WEST PAPUA.

L. cryptocera Emery , 1897: 592, pl. 15, fig. 34; Lemien, near Berlinhafen (= Aitape), PAPUA NEW GUINEA.

L. curvata Sarnat, 2006: 15, figs 2, 3; Kasavu village, Vanua Levu, FIJI.

L. desupra Sarnat, 2006: 17, figs 4, 5; Monasavu Rd, Viti Levu, FIJI.

L. epinotalis (Mann) , 1919: 343; Ysabel, SOLOMON ISLANDS ( Rogeria epinotalis ) (Combination: Kugler, 1994: 26).

L. furcifera Emery , 1897: 591, pl. 15, figs. 32, 33; Lemien, near Berlinhafen (= Aitape), PAPUA NEW GUINEA.

= bensoni Donisthorpe , 1949: 94, figs 1, 2; Maffin Bay, WEST PAPUA. NEW SNONYMY.

L. infundibuli Donisthorpe , 1940: 45, 2 figs; Jutefa Bay, Pim, WEST PAPUA.

L. leae Wheeler , 1919: 102, fig. 4 a-e (not fig. 3, as captioned, see Wheeler, 1927:143); AUSTRALIA: Lord Howe Island.

L. levifrons (Mann) , 1921: 453; Nadarivatu, Viti Levu, FIJI ( Rogeria (Irogeria) tortuosa levifons )(Combination in Lordomyrma : Kugler, 1994: 26. Species rank: Sarnat, 2006: 20).

L. nigra Donisthorpe , 1941: 36; Camp Nok, Waigeu I., WEST PAPUA. ( Lordomyrma niger ).

L. nobilis Yasumatsu : see L. azumai .

L. polita (Mann) , 1921: 453; Nadarivatu, Viti Levu, FIJI ( Rogeria (Irogeria) tortuosa polita ) (Combination in

Lordomyrma : Kugler, 1994: 26. Species rank: Sarnat, 2006: 21).

L. punctiventris Wheeler , 1919: 105, fig. 3 a, b (not fig. 4, as captioned, see Wheeler, 1927:143); Kuranda, Queensland, AUSTRALIA.

L. reticulata Lucky & Sarnat, 2008: 39, figs 2,3; Danum Valley, Sabah, MALAYSIA.

L. rouxi (Emery) , 1914: 413, plate 13, fig. 8, a, b; Tchalabel, NEW CALEDONIA (Promeranoplus rouxi ) (Combination: Bolton, 1995: 248).

L. rugosa (Mann) , 1921: 455, fig. 20; Nadarivatu, Viti Levu, FIJI ( Rogeria (Irogeria) rugosa ) (Combination: Kugler, 1994: 26).

L. sarasini (Emery) , 1914: 414, plate 13, figs 9, a, b; Mt. Ignambi, NEW CALEDONIA ( Prodicroaspis sarasini ) (Combination: Bolton, 1995: 248).

L. stoneri (Mann) , 1925: 5; Tamavua, Suva, Viti Levu, FIJI ( Rogeria (Irogeria) tortuosa stoneri ) (Combination in Lordomyrma : Kugler, 1994: 26. Species rank: Sarnat, 2006: 25).

L. striatella (Mann) , 1921:454, fig. 19; Kadavu, Vanua Ava, FIJI ( Rogeria (Irogeria) striatella ) (Combination: Kugler, 1994: 26).

L. sukuna Sarnat, 2006: 29, figs 16, 17; Mt Naqaranibuti, Viti Levu, FIJI.

L. tortuosa (Mann) , 1921: 452, fig. 18; Levuka, Ovalau, FIJI ( Rogeria (Irogeria) tortuosa ) (Combination: Kugler, 1994: 26).

L. vanua Lucky & Sarnat, 2008: 42, figs 2,3; Mt Delaikoro, Vanua Levu, FIJI.

L. vuda Sarnat: 2006: 34, figs 20, 21; Savione Falls, Koroyanitu National Park, Viti Levu, FIJI.

The Australian species described as Lordomyrma rugosa Clark , 1934, is now assigned to Podomyrma Fr. Smith (Brown, 1956; Taylor, 1987) as a junior synonym of P. christae (Forel) . The nomen nudum L. longiseta used in error by Sarnat (2006: 37) does not preoccupy that name in Lordomyrma .

All the listed species have worker holotypes or syntypes. The gyne was originally characterized for L. infundibuli and males for L. azumai, L. leae and L. striatella . Types of most names have been examined (apart from L. reticulata and those described from Fiji by Sarnat). Most species are represented in the ANIC by paratypes, syntypes, type-compared vouchers, or confidently identified specimens assembled during this study.

The new combinations result mostly from the new generic synonymies proposed. The elevation of L. accuminata to species rank and the furcifera = bensoni synonymy follow direct comparison of relevant types (including that of L. cryptocera , of which accuminata was previously a subspecies) from the Hungarian Natural History Museum, Budapest, or The Natural History Museum, London, UK ( BMNH), considered with modern ANIC specimens.

The Asian Lordomyrma fauna

Apart from the Japanese L. azumai (Figs 1, 2), known from southern Honshu, Shikoku and Kyushu (Imai et al, 2003: 102), the Bornean L. reticulata , and a generic listing from Sabah in Bruhl et al (1998), Lordomyrma species have not been previously reported from areas north or west of New Guinea. Six or seven undescribed, allopatrically-distributed species are now represented in the ANIC and BMNH collections. Others considered here were provided by Seiki Yamane, Katsuyuki Eguchi, Fuminori Ito and Martin Pfeiffer. These taxa will be reviewed in the second paper of this series, now in preparation. No sympatric associations are known.

These species are morphologically conservative, with relatively low disparity (in the sense of Gould, 1989: 49 - i.e. without major interspecific variability in structure). All are basically similar to L. azumai . The latter has palpal formula maxillary 4:labial 3, versus 3:3 in one SE Asian species and 3:2 in others. A small, wide-ranging species from peninsular Malaysia, Sarawak, Sabah and Rakata I (Krakatau) resembles L. azumai , as do others from Luzon and Sarawak. Several Bornean species are larger, with heavier sculpturation and long pilosity. Compared to the Lordomyrma type-species, L. furcifera (Figs 7, 8 - illustrated also in dorsal view as L. bensoni by Donisthorpe, 1949, figs 1, 2) all are relatively heavily sculptured, with strongly defined antennal scrobes, which are differently (less heavily) sculptured than other frontal parts of the head, much more conservative mesosomal structure and unexceptionally developed propodeal spines. They lack dorsally rounded or spinose extensions to the petiole or postpetiole. Several have relatively heavy gastral sculpturation (see illustrations of L. reticulata (Sarnat & Lucky, 2008)).

The congeneric affinity between L. azumai and L. furcifera was recognized by Yasumatsu (1950). The extremes between the azumai habitus and that of furcifera are now more clearly bridged than before by several known New Guinean species, including L. cryptocera (Figs 5, 6) and L. infundibuli (Figs 9, 10).

Given this wide distributional range with limited records it is certain that more Asian Lordomyrma species in nature must await discovery.

Australian Lordomyrma species

There are at least 4 or 5 known mainland eastern Australian species represented in the ANIC and confidently referable to Lordomyrma . L. punctiventris (Figs 3, 4), alone is named. The similar L. leae is known only from Lord Howe Island.

Interspecific morphological diversity is low among Australian Lordomyrma species, as in the Asian species, which they generally resemble (compare Figs 1, 2 with Figs 3, 4 - undescribed Asian and Australian species are even more alike than these). They likewise relate to bridging elements of the New Guinean fauna, including L. cryptocera (Figs 5, 6), sufficiently to confirm their long-recognized congeneric affinity with L. furcifera , and assignment to Lordomyrma . The palpal formula in four investigated species is 3:3.

The mainland Australian species are deployed along the continental east coast and Great Dividing Range, in rain forest or wet sclerophyll habitats, from Iron Range (12o S lat.) in the north, to central New South Wales (Shattuck, 1999, fig 502). Few sympatric associations are represented. The known Iron Range species has affinities with others from New Guinea (it is for example the only Australian species lacking antennal scrobes, structures absent in several New Guinean and some New Caledonian species). The more southern Australian taxa, with L. leae , constitute a close-knit species group, that of L. punctiventris . An undescribed species similar to L. punctiventris was illustrated by Holldobler & Wilson, 1990: 110.

Lordomyrma species of lowland New Guinea and adjacent islands

Over 20 Lordomyrma species are known from New Guinea and adjacent Islands, but only 9 have been named. Most were described originally in Lordomyrma .

There is much greater structural variability among these species than those of Asia and Australia combined; the fauna is thus both species-rich and morphologically diverse.

Four taxa ( L. crawleyi, L. cryptocera, L. infundibuli and L. furcifera , with its junior synonym L. bensoni ), were described from a 175-180 km section of the north coast of mainland New Guinea, between Maffin Bay (138o51'E), West Papua, and Aitape (142o21'E), Papua New Guinea. The L. accuminata and L. rupicapra types very likely also came from near the north coast of the former German colony of Kaiser Wilhelms Land, between 141oE and 148oE. L. niger was described from 2, 500 ft. on Waigeo (= Waigeu) I., northwest of the West Papuan Vogelkop, and L. epinotalis far to the east, from Ysabel I, Solomon Islands.

As indicated above, L. cryptocera (Figs 5, 6) is the described Melanesian taxon most similar to those of Asia and Australia. This pivotal species relates separately and easily to L. accuminata and niger (neither yet illustrated), to the distinctive infundibuli (Figs 9, 10), and to a group of aberrant species close to furcifera (Figs 7, 8), including L. crawleyi (Figs 11, 12).

Other undescribed lowland New Guinean species appear to represent several additional lineages derived from stock similar to L. cryptocera , so that recognition of further species groups seems likely. New Guinea species have known palpal formulae of 3:3 or 3:2.

Unknown Lordomyrma species must be present in lowland New Guinea and on other Melanesian islands.

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 Developpement (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 km2) 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.

Lordomyrma species of the Fiji islands

The Fijian Lordomyrma were monographed and comprehensively illustrated by Sarnat (2006), supplemented by Lucky & Sarnat (2008). Five species additional to six recognized by W.M. Mann in the 1920's were described. They constitute the species group of L. rugosa . Inclusion in Lordomyrma is readily confirmed by comparison of Figs 21-22 with those of L. azumai (Figs 1, 2), L. cryptocera (Figs 5, 6) and L. infundibuli (Figs 9, 10 - see also Sarnat's (2006) figures). The group is significantly species-rich considering the size of Fiji. It evidences morphological variability much less spectacular than in the western Melanesian and New Caledonian faunas, and essentially as low as that of the Asian and Australian species. Nine of the twelve known species are from relatively well-collected Viti Levu, and two only from Vanua Levu. L. tortuosa is known from seven of eight investigated islands, and several Viti Levu species are widespread on other islands

Because of this high species richness and low morphological disparity, the Fijian species are of special interest relative to the very species-rich but additionally highly morphologically diverse faunas of lowland New Guinea and New Caledonia. These various faunas could well be important for analysis in comparative studies investigating the nature and mechanisms of speciation (generating species richness) and adaptive radiation(generating morphological and biotic diversity) among ants.

There seems likely to be relatively less interspecific competition between congeneric species in Fiji than in the more richly concentrated Lordomyrma faunas of lowland New Guinea and New Caledonia. These differences in relative species density might have influenced the levels of morphological divergence in the several faunas, as effects resulting from ecological displacement among related competing species. The two main Fijian Islands, Viti Levu and Vanua Levu, are together about as large as mainland New Caledonia - their areas are 4, 001 sq.mi. (c. 10, 360 sq.km.) and 2, 137 sq.mi. (c. 5, 535 sq.km.) respectively (Robson 1963).

The collection and study of Fijian Lordomyrma species (and those of other ant genera significantly species-rich on the islands - e.g. Hypoponera , Leptogenys , Gnamptogenys , Strumigenys , Pheidole , Camponotus and others, along with the endemic myrmicine genus Poecilomyrma ) deserves special scientific attention, and highlights the need for more vigorous conservation of the remaining stands of native Fijian rain forest.