Iridomyrmex tenebrans, Heterick & Shattuck, 2011

Heterick, Brian E. & Shattuck, Steve, 2011, Revision of the ant genus Iridomyrmex (Hymenoptera: Formicidae) 2845, Zootaxa 2845 (1), pp. 1-174 : 147-148

Iridomyrmex tenebrans sp. n.

( Fig. 78 )

Types. Holotype worker from Crowdy Bay National Park , 10km S Laurieton, 31°47’S 152°45’E, New South Wales, September 1992, E. A. Davidson ( ANIC, ANIC32-013752 ).

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. Frontal carinae straight; antennal scape barely attaining posterior margin of head, or surpassing it by less than 1 x its diameter. Erect setae on scape absent, except at tip; prominence on anteromedial clypeal margin present as an indistinct swelling or undulation; mandible regularly triangular with oblique basal margin; long, curved setae on venter of head capsule present. Mesosoma. Pronotum moderately and evenly curved over its length. Erect pronotal setae numerous (12 or more), short and bristly. Mesonotum evenly curved. Erect mesonotal setae moderate in number (6- 12), short and bristly. Mesothoracic spiracles always inconspicuous; propodeal dorsum protuberant; placement of propodeal spiracle mesad, more than its diameter away from propodeal declivity; propodeal angle present as a bluntly defined right angle, the dorsal and declivitous propodeal faces never separated by a carina. Erect propodeal setae numerous (12 or more), short and bristly. Petiole. Dorsum of node convex; node thin, scale-like, orientated anteriad. 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 reddish-brown. Colour of erect setae whitish.

Measurements. Worker (n = 1)—CI 95; EI 26; EL 0.28; EW 0.23; HFL 1.23; HL 1.11; HW 1.06; ML 1.42; MTL 0.84; PpH 0.25; PpL 0.60; SI 85; SL 0.90.

Comments. As is the case with several other members of the I. viridigaster complex, this species seems to be exceedingly rare, and is known only from the holotype, collected at Crowdy Bay, New South Wales. The sole worker is distinguished by its dark appearance from other members of the complex with a hairy mesosoma and erect setae on the hind tibiae. Nothing further is known of this ant .

Etymology. Latin: ‘rendered obscure’.

Figures

FIGURE 78. Iridomyrmex tenebrans (holotype, Crowdy Bay, NSW, ANIC32-013752): A. Front of head; B. Side of body; C. Top of body; D. Distribution of material examined.