Eurhopalothrix insidiatrix

Workers have been collected from sifted litter.

Identification
Eurhopalothrix insidiatrix workers can be distinguished from the only other Fiji Eurhopalothrix, Eurhopalothrix emeryi, by the more reticulated and random appearance of the cephalic and mesosomal rugae.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Fiji.

Nomenclature

 *  insidiatrix. Eurhopalothix insidiatrix Taylor, 1980b: 238, figs. 11-14 (w.q.) FIJI IS.

Worker
Dimensions [holotype, smallest para type (Suene), largest paratype (Ndelaikoro), selected by HW measurement).- TL ca 5.7, 5.5, 6.0; HL 1.42, 1.35, 1.49; HW 1.39, 1.36, 1.49; CI 99, 100, 100; ML 0.36, 0.35, 0.42; MI 25, 26, 28; SL 0.79, 0.78, 0.84; SI 57, 57, 56; maximum diameter of eye 0.14, 0.14, 0.17; PW 0.84, 0.82, 0.92; WL 1.62, 1.58, 1.80; petiolar node width 0.32, 0.32, 0.38; postpetiole width 0.72, 0.68, 0.80; gastral width 1.05, 1.02, 1.19.

Close to Eurhopalothrix emeryi distinguished from it by the following features:

1. Larger size, with relatively broad head and long scapes.

2. Sculpturation of mandibles less coarse and more extensively developed. Clypeus and front of head almost completely coarsely rugoreticulate, linear elements restricted to a few short longitudinal costae near midline, immediately behind the clypeus.

Entire pronotum, mesonotal dorsum and basal face of propodeum generally sculptured like head, with traces of longitudinal costae near midline behind pronotum. Diagonal wavy costae somewhat similar to those of E. emeryi restricted on sides of mesosoma to metepisternum and propodeum. Traces of this sculpture weakly developed in the rugosity of the mesepisternum and extreme posterior parts of the sides of the pronotum.

3. Erect specialised hairs barely differentiated at all from ground pilosity. The specimens are generally worn or encrusted with dirt or secreted material. However all hairs present in E. emeryi, except those adjacent to the eyes, seem to be represented somewhere in the series.

Queen
The Ovalau female differs from those of E. emeryi exactly as would be expected considering the worker differences listed above; notably the sculptural features.

Type Material
Type Locality: FIJI: VANUA LEVU: Suene, hololype and 24 paralypes, all workers, W. M. Mann, collected in 1915-16 ( (holotype, 10 paratypes), (12 para types),  (two paratypes)); Ndelaikoro, litter, ca 800 m, 27.x.1977, GK (acc. 77/131), five paratype workers ( (three), ANIC (two)). VITI LEVU: Waiyanitu, three paratype workers, W. M. Mann, 1915-16 (USNM). OVALAU ISLAND: paralype deal ate female, W. M. Mann, 1915-16 (USNM). All specimens except those from Ndelaikoro are also types of Rhopalothrix (Rhopalothrix) elegans.

Some specimens in Mann's series of both E. emeryi and E. insidiatrix have lost the postpetiole and gaster. These have been reglued to the mounting points in several cases, and at least one E. emeryi gaster has been incorrectly associated with a broken E. insidiatrix specimen. This or its complement might also have occurred with specimens not seen by me.

References based on Global Ant Biodiversity Informatics

 * Dlussky G.M. 1994. Zoogeography of southwestern Oceania. Zhivotnoe naselenie ostrovov Iugo-Zapadnoi Okeanii ekologo-geograficheskie issledovanii 48-93.
 * Sarnat Eli M. 2009. The Ants [Hymenoptera: Formicdiae] of Fiji: Systematics, Biogeography and Conservation of an Island Arc Fauna. 80-252
 * Taylor R. W. 1980. Australian and Melanesian ants of the genus Eurhopalothrix Brown and Kempf - notes and new species (Hymenoptera: Formicidae). Journal of the Australian Entomological Society 19: 229-239.
 * Ward, Darren F. and James K. Wetterer. 2006. Checklist of the Ants of Fiji. Fiji Arthropods III 85: 23-47.