Iridomyrmex cuneiceps, Heterick & Shattuck, 2011

Heterick, Brian E. & Shattuck, Steve, 2011, Revision of the ant genus Iridomyrmex (Hymenoptera: Formicidae) 2845, Zootaxa 2845 (1), pp. 1-174 : 67-68

Iridomyrmex cuneiceps sp. n.

( Fig. 27 )

Types. Holotype worker from 13mi. SW Mundiwindi , Western Australia, 26 April 1963, McInnes & Dowse ( ANIC, ANIC32-041030 ) . Paratypes: 5 workers, same data as holotype ( ANIC) ; 4 workers from Kanka WH near Warburton , Western Australia, 3 October 1980, H. Heatwole ( ANIC, ANIC32-037500 , 2 workers; MCZC, ANIC32-037499 , 2 workers) .

Worker Description. Head. Posterior margin of head planar to weakly concave; erect setae on posterior margin in full-face view set in a row; sides of head noticeably convex; erect genal setae absent from sides of head in full-face view (one to a few small setae may be present near mandibular insertion). Ocelli absent; in full-face view, eyes set at about midpoint of head capsule; in profile, eye set anteriad of head capsule; eye semi-circular, or asymmetrical, curvature of inner eye margin more pronounced than that of its outer margin. Frontal carinae convex; antennal scape surpassing posterior margin of head by approximately 2 x its diameter. Erect setae on scape absent, except at tip; prominence on anteromedial clypeal margin projecting as blunt but distinct protuberance; mandible regularly triangular with oblique basal margin; long, curved setae on venter of head capsule absent. Mesosoma. Pronotum moderately and evenly curved over its length. Erect pronotal setae sparse (6 or fewer) and bristly. Mesonotum straight. Erect mesonotal setae sparse (6 or fewer) and bristly. Mesothoracic spiracles always inconspicuous; propodeal dorsum smoothly and evenly convex; placement of propodeal spiracle mesad, more than its diameter away from propodeal declivity; propodeal angle weakly present or absent, the confluence of the dorsal and declivitous propodeal faces indicated, if at all, by an undulation. Erect propodeal setae sparse (6 or fewer) and bristly. Petiole. Dorsum of node convex; node thin, scale-like, orientation more-or-less vertical. Gaster. Non-marginal erect setae of gaster present on first gastral tergite; marginal erect setae of gaster present on first tergite. General characters. Allometric differences between workers of same nest absent. Colour uniformly brown. Colour of erect setae pale yellow.

Measurements. Worker (n = 2) — CI 86; EI 25-27; EL 0.24; EW 0.18-0.19; HFL 1.23-1.28; HL 1.03-1.09; HW 0.88-0.93; ML 1.20-1.24; MTL 0.90-0.95; PpH 0.18-0.20; PpL 0.47-0.54; SI 108-109; SL 0.94-1.02.

Comments. Iridomyrmex cuneiceps is a medium-sized, brown ant. The main feature that will enable it to be distinguished from I. suchieri , the species with which it is most likely to be confused, is the very thin vertex when the ant is seen in profile. In this respect it rather resembles Camponotus perjurus Shattuck & McArthur. Known populations of this uncommon ant appear to be confined to northern inland regions of Western Australia, although it may also occur in remote regions of the Northern Territory. The species has been collected by hand near Leinster, in a rocky, desolate area, by the first author of this paper.

Etymology. Latin: ‘ cuneus ’—‘wedge’ plus ‘ ceps ’ derivative of ‘ caput ’—‘head’.

Figures

FIGURE 27. Iridomyrmex cuneiceps (Warburton, WA, ANIC32-037500): A. Front of head; B. Side of body; C. Top of body; D. Distribution of material examined.