Monomorium rothsteini

Sparks et al. (2015) have split what was once thought to be a variable, widespread species into many species. Under this new taxonomic hypothesis past distribution data reported for Monomorium rothsteini and any studies involving this ant need to be reevaluated to determine what species they include.

Identification
Sparks et al. (2015) - Small amber species with a concave clypeal margin. The dorsal surface of the propodeum lack longitudinal strigae and the longitudinal depression is very shallow or absent giving the propodeum and rounded appearance.

Distribution
This species is known from the coastal and inland regions of central and northern Queensland.

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Genetics
COI sequences. Genbank accession numbers for this species are KC572911–KCC572920 and KC572923.

Nomenclature

 *  rothsteini. Monomorium rothsteini Forel, 1902h: 444 (w.) AUSTRALIA. Imai, Crozier & Taylor, 1977: 348 (k.); Heterick, 2001: 409 (q.m.). Combination in M. (Parholcomyrmex): Santschi, 1919a: 328; in Chelaner: Ettershank, 1966: 97; in Monomorium: Taylor, 1987b: 3. Senior synonym of doddi: Heterick, 2001: 408; Sparks, Andersen & Austin, 2015: 517.
 * doddi. Monomorium (Parholcomyrmex) rothsteini st. doddi Santschi, 1919a: 328 (w.) AUSTRALIA. Combination in Chelaner: Ettershank, 1966: 96; in Monomorium: Taylor, 1987b: 3. Junior synonym of rothsteini: Heterick, 2001: 408; Sparks, Andersen & Austin, 2015: 517.

Worker
Sparks et al. (2015) - (n=9). HW 0.70–0.96, HL 0.74–0.96, EL 0.16–0.18, PMH 0.29–0.37, PH 0.25–0.33, PNH 0.18–0.23, LHW 0.45–0.59, EW 0.10–0.12, PML 0.47–0.64, ML 0.80–1.05, PL 0.37–0.43, PNWdv 0.20–0.27.

Small species with a medium sized, rectangular head which narrows from immediately behind eyes to vertex; posterior cephalic margin shallowly depressed medially. Anterodorsal margin of the clypeus concave with frontolateral carinae forming rounded ridges that extend just beyond anteroventral clypeal margin, anterolateral angles are bluntly rounded; anteroventral margin without a small median projection, margin appears straight. Sculpture on frons variable: strigate, extending well above antennal lobes or restricted to antennal lobes and area in between or rarely limited to a few strigae only present on antennal lobes; coarse lateral cephalic strigae not reaching eye margin or rarely with one or two strigae reaching eye margin. Eyes medium, EW 0.20–0.23 x LHW, 10 ommatidia in longest vertical axis, 8 in longest horizontal axis.

Mesonotum with coarse strigae extending from metanotal groove onto posterior region only, rugulose between strigae, remainder smooth and shining; posterior mesonotum generally flat and contiguous with surrounding surface of mesonotum or rarely raised with a faint horseshoe shaped margin. Mesopleuron alveolate with strigulae spanning area between metanotal groove and promesonotal suture on dorsal half. Propodeum in lateral view with dorsolateral angles clearly forming an obtuse angle; laterally alveolate with 3–4 strigae over the metapleural gland bulla; dorsally with anterodorsal transverse carina present, a few weak transverse strigae present on some specimens, longitudinal carinae absent, longitudinal depression very shallow or absent, propodeum appears flat or slightly rounded dorsally; posterolateral corners rounded above metapleural lobes and dorsolateral angles rounded. Petiole node of medium breadth: between 2 and 2.5 x eye width when viewed from above; shape in posterior view oval, in lateral view anterior and posterior faces converging, apex narrowly rounded from higher anterior face to lower posterior face; posterior surface of petiole node finely reticulate laterally and basally but not extending more than half way to dorsal surface or may appear to be without sculpture, smooth and shining, postpetiole faintly reticulate on posterior surface.T1 completely smooth and without sculpture.

Head and mesosoma dark amber orange to orange brown, legs brown, petiole and postpetiole dorsally infuscated, metasomal tergites dark brown.