Peronomyrmex overbecki

A rarely collected species that is known from two workers.

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Biology
Taylor (1970) - This species is known from a single specimen. It bears the following data: (1) two white labels in different handwriting with “Peronomyrmex overbecki Viehm.”; (2) a white printed label reading “Coll Viehm”; (3) a red printed label reading “Typus”; (4) a large plain yellow label. There is no indication of the collection locality, collector, or other data. The original description gave these as: “Australien, N.S.W.: ein Stuck aus dem Walde bei Trial Bay, (H. Overbeck).” Brown (1949) has questioned the collection localities of this and other species described by Viehmeyer. (Shattuck 2006)

Shattuck (2006) - A second specimen of this species was recently (November, 2003) collected in Brisbane by Chris Burwell of the Queensland Museum (pers. comm.). He hand collected the specimen at night, apparently from a tree trunk (although the specific collecting details were not recorded). This nocturnal habit, combined with its likely arboreal foraging and nesting, helps explain why these ants are so infrequently encountered.

Nomenclature

 *  overbecki. Peronomyrmex overbecki Viehmeyer, 1922: 213, fig. 2 (w.) AUSTRALIA. See also: Taylor, 1970b: 209.

Worker
Taylor (1970) - General features as illustrated. Dimensions as follows: aggregate total length c. 4.1 mm; maximum head length 0.91 mm; maximum head width (behind eyes) 0.74 mm; maximum diameter of eye 0.19 mm; scape length 0.64 mm; cephalic index 81; scape index 87; width across pronotal humeri 0.59 mm; Weber's length of thorax 1.03 mm; dorsal petiole width 0.21 mm; maximum petiole height 0.58 mm; dorsal postpetiole width 0.30 mm; maximum postpetiole height 0.60 mm.

Clypeal disc, frons between frontal carinae, thorax, petiole, postpetiole and gaster generally shining, though virtually nowhere entirely smooth, but with a minute and very finely incised net or scale-like microreticulation. Superimposed macrosculpturation on various parts as follows: lateral areas of clypeus longitudinally striate, some striae curving below and behind antennal foveae. Sides of head, especially anterior to eyes, finely longitudinally striate-rugose. Lateral areas of thoracic dorsum finely and irregularly longitudinally striate. Propodeal declivity smooth and shining, transversely convex below propodeal spines. Sides of thorax with fragmentary and scattered longitudinal striae. Petiole and postpetiole lacking macrosculpture, gaster relatively shining, microreticulate, with scattered minute blister-like hair follicles. Mandibles, antennae and legs moderately shining, with very fine, dense, piligerous point punctures and almost no microreticulation.

Head, thoracic dorsum and apices of nodes generally covered with short erect to suberect hairs. Longer suberect hairs abundant on mandibles, sides of clypeus, sides of head anterior to eyes, and gaster; those of mandibles and gastral apex longest, a few on crests of petiole and postpetiole.

Colour dull chestnut-brown, the gaster darker, eyes black.

References based on Global Ant Biodiversity Informatics

 * Taylor R. W. 1987. A checklist of the ants of Australia, New Caledonia and New Zealand (Hymenoptera: Formicidae). CSIRO (Commonwealth Scientific and Industrial Research Organization) Division of Entomology Report 41: 1-92.
 * Taylor R. W. 1991. Nomenclature and distribution of some Australasian ants of the Myrmicinae (Hymenoptera: Formicidae). Memoirs of the Queensland Museum 30: 599-614.