Adelomyrmex hirsutus Mann 1921

In Fiji: Adelomyrmex hirsutus is a dark shiny species with wide well-defined foveae evenly distributed across the head and gaster. Although there is some minor variation in the sculpture across the archipelago, there is no morphologic evidence of highly structured populations. The specimens from New Caledonia that are reported as A. hirsutus (Wilson & Taylor, 1967) were apparently not examined by Fernndez (2003), who did not include the island as part of the Adelomyrmex distribution, although they do lend circumstantial credence to the Gondwanian origin hypothesis. The two New Caledonian specimens examined for the present study match poorly against the type specimen and the additional Fijian material. Though near A. hirsutus, the New Caledonian specimens entirely lack the distinctive foveae of the Fijian specimens, and in profile the petiole is characterized by a significantly narrower node and longer peduncle.

The single specimen Mann collected was a worker of A. hirsutus found beneath a stone, and his conclusion that the species was hypogaeic is supported by recent collections. All of the specimens collected during the recent survey were taken from sifted litter.

Adelomyrmex (Arctomyrmex) hirsutus Mann, 1921 PDF: 458, fig. 21 (w.) FIJI IS (Vanua Levu). Oceania. AntCat AntWiki HOL

Taxonomic history

Status as species: Wheeler, 1935g: 29; Dlussky, 1994a: 55; Bolton, 1995b: 58; Fernández, 2003b PDF: 18 (redescription); Sarnat & Economo, 2012 PDF: 70.

Adelomyrmex (Arctomyrmex) hirsutus Mann , 1921:458 (w).

Adelomyrmex hirsutus : Bolton, 1995:58. [ Holotype worker examined, USNM ].

Worker measurements (n=1). HL 0.61 HW 0.50 SL 0.35 EL 0.06 WL 0.58 GL 0.72 TL 2.36 CI 82 SI 70.

Worker diagnosis. The last antennal flagellomere large, nearly as long as the remainder of antennal funiculus. Eyes reduced to dark spots. Metanotal groove slighty impressed. Propodeal spiracle round and small. Dorsal surface of propodeum shorter than declivituous face, with two very short and triangular spines. Propodeal lobe subtriangular, slightly pointed. Protibiae swollen near apex. Head, mesosoma, petiole and postpetiole smooth and shining, puncturated, punctures more or less closed. Longitudinal midline of head without punctures. Most of declivitous face of propodeum smooth and shining with median keel joining the propodeal spines; most of lateral sides of thorax smooth and shining with spaced punctures; meso and metapleuron longitudinally rugose; petiolar sculpture similar to head. Body light brown, legs yellowish brown; abundant median whitish pilosity on head dorsum, scapes, thorax dorsum, petiole, postpetiole and gaster. Appressed pilosity on funiculus. Shorter and reclinated pilosity on legs.

Comments. A. hirsutus can be separated from A. samoanus by eye condition (they are reduced to dark spots); mesosoma outline, as seen in side view; and head sculpturing (punctate in hirsutus , punctate striate in samoanus ).