Metapone truki M.R. Smith, 1953

Taylor, Robert W. & Alpert, Gary D., 2016, The myrmicine ant genus Metapone Forel (Hymenoptera: Formicidae): a global taxonomic review with descriptions of twelve new species, Zootaxa 4105 (6), pp. 501-545 : 526-529

16. Metapone truki M.R. Smith, 1953

( Figs 81 –90)

Metapone truki M.R. Smith, 1953:135 , worker; Type locality: Caroline islands, Truk (properly Chuuck) Island [7°00’N, 152°00’E].

Distribution, material examined. A relatively widespread species known from mainland New Guinea, New Britain and several Micronesian islands. Possibly dispersed by human activity. MICRONESIA CAROLINE ISLANDS: Truk Island: North Basin, Mt Chukumong, Moen, ex rotten breadfruit (R.W.L Potts, II-10-49) holotype worker (USNMNH, Type No 61855), paratype worker (CASC). Truk: no further data (Matsushima, xii-28-36) 2 mounted workers, and vial with brood (MCZC). Dublon (= Tonoas) Island [7°22'N, 151°52'](Z. Ono, XII 22 ’35), 2 very damaged alate gynes (MCZC), 2 workers (LACMNH): Palau islands: Koror Island [7°21N’, 134°38’E]: limestone ridge south of inlet, under dead bark (H.S. Dybas, 21 Jan. 1948) dealate gyne (MCZC). PAPUA NEW GUINEA: Madang province: Upper Gogol Valley, ca 24km W of Madang [5°4’S, 145°46’E], colony series ex rotting log, rainforest, ca 50m. (RWT, 20–23, 6, 1972) (ANIC). EAST NEW BRITAIN: Yalom [4°25'S, 151°45'E], 1000m (Noona Dan Expedition, 11 May 1962) 2 workers.

Our concept of M. truki is based on assertion of conspecificity between the holotype worker and workers from the various samples listed above. The New Guinean Gogol Valley colony series provides confident identification of a worker-associated gyne. Its smaller workers closely match the Micronesian holotype, and its larger workers demonstrate that there can be considerable intranidal size variation in this species. The specimens from Dublon Island are individually mounted on separate pins and identically labelled. They were almost certainly collected together, providing a matching Melanesian worker-gyne association. The Gogol colony was collected in lowland rainforest near the edge of a large recently (and environmentally questionably) clear-felled tract at a site previously deep in virgin forest, and thus almost certainly a “native” habitat unlikely to have been penetrated by an introduced species. We conclude that M. truki is probably of New Guinean rather than Micronesian origin, and that the Micronesian populations were likely derived from one or more introduced New Guinean propagules. The appropriate areas were subject to much aircraft and shipping movement by both Japanese and American forces during the Second World War (1942–1945).

Worker diagnosis. General features as illustrated and in the key to Micronesian, Melanesian and Pacific species above.

Dimensions (listed in order: M. truki holotype; other Micronesian workers: smallest (M. truki Paratype, largest (LACMNH Dublon Island specimen); Gogol Valley colony series: smallest; largest): TL(ca): 6.0; 5.1, 6.2; 5.1, 6.8. HL: 1.18; 1.13, 1.32; 1.10, 1.61. HW: 0.88; 0.85, 0.95; 0.78, 1.11. CI: 75; 76, 72; 71, 69. CpL: 0.43; 0.41, 0.50; 0.42, 0.57. CpI: 36; 36, -; -, 35. MSL: 1.44; 1.40, 1.65; 1.34, 1.96. PML: 0.75; 0.73, 0.88; 0.70, 1.03. PMW: 0.61; 0.57, 0.63; 0.55, 0.76. PMI: 52; 52, 53; 52, 53. PDW: 0.57; 0.52, 0.58; 0.47, 0.67. PetL: 0.44; 0.39, 0.47; 0.37, 0.62.

PetW: 0.35; 0.34, 0.40; 0.33, 0.51. PetH: 0.62; 0.57, 0.69; 0.54, 0.79. PpetL: 0.34; 0.32, 0.41; 0.32, 0.53. PpetW: 0.45; 0.43, 0.55; 0.41, 0.67. PpetH: 0.49; 0.47, 0.57; 0.44, 0.67. GW: 0.91; 0.88, 0.96; 0.85, 1.23.

Gyne diagnosis. General features as illustrated.

Dimensions: Gogol Valley colony Gyne: HL: 1.68, HW (across eyes): 1.06, CI: 63, CpL: 0.61, CpI: 36, WL: 3.52, PetL: 0.66, PetW: 0.52, PetH: 0.86, PpetL: 0.53, PpetW: 0.68, PpetH: 0.66, GW: 1.21. The Koror gyne is small and relatively heavily sculptured.

Voucher specimen record The Koror Island gyne is labelled “ Voucher specimen Gottwald study 1968 My- 109 ”. Its mouthparts were discussed and illustrated by W.H. Gottwald (1969: p107, plate 80).

Figures

FIGURES 81 – 85. Metapone truki, holotype gyne; FIGURES 86 – 90, worker, see text for dimensions.