Metapone truki

A relatively widespread species known from mainland New Guinea, New Britain and several Micronesian islands. Possibly dispersed by human activity.

Identification
(In gynes & workers) Striae in relevant areas less-strongly developed and less-regular; partly effaced, especially on frons and cheeks. Clypeal proboscis relatively short and broad. Petiole relatively short in lateral and dorsal view. Subpetiolar extension similar to alternative, but with its apex acutely pointed (mainland New Guinea, gyne and worker).

Distribution based on Regional Taxon Lists
Indo-Australian Region: Micronesia (Federated States of), New Guinea.

Biology
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).

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).

Nomenclature

 *  truki. Metapone truki Smith, M.R. 1953d: 135 (w.) TRUK I.

Taylor and Alpert (2016) - Our concept of M. truki is based on assertion of conspecificity between the holotype worker and workers from various samples. 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.

Worker
Taylor and Alpert (2016) - (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.

Queen
Taylor and Alpert (2016) - 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.

Type Material
Taylor and Alpert (2016) - Worker: Caroline islands, Truk (properly Chuuck) Island [7°00’N, 152°00’E].