Monomorium topend Sparks

Sparks, Kathryn S., Andersen, Alan N. & Austin, Andrew D., 2014, Systematics of the Monomorium rothsteini Forel species complex (Hymenoptera: Formicidae), a problematic ant group in Australia, Zootaxa 3893 (4), pp. 489-529 : 524-527

Monomorium topend Sparks , NEW SPECIES

( Fig. 8 d–f, 10d–f, 11c)

Holotype worker. Northern Territory, Marrara, Darwin , -12.3983, 130.8958, 7 May 2008, A.N. Andersen, TERC75 (deposited in NTM).

Paratypes. Northern Territory. 22 workers, same data as holotype; 9 workers, CSIRO Darwin Lab, Berrimah, -12.4167, 130.9167, 23 May 2008, A. Andersen, TERC 46; 23 workers, Territory Wildlife Park, -12.7000, 130.9833, 22 Jul 2008, A.N. Andersen, TERC 65; 13 workers, Adelaide River township, -13.2383, 131.1053, 13 Jul 2008, A.N. Andersen, TERC 72; 5 workers, Berrimah, -12.4152, 130.9231, 11 Dec 2008, K. Sparks, KSS22; 20 workers and 15 males, KSS21; 16workers, Territory Wildlife Park, Berry Springs, -12.6974, 130.9904, 24 Sep 2009 A1, A. Andersen, ANA09–12; 5 workers, A3, ANA09–13; 6 workers, A1, ANA09–14 ( NTM, QM, SAM, WAM).

Diagnosis. A large, amber orange species with a shallowly concave to sinuous clypeal anterodorsal margin, strigate frons, cuboid propodeum and very broad petiole node. This species cannot be separated from M. geminum sp. nov. based on morphology, but the two species are easily separated from all other species here by their very broad petiole node in combination with a shallowly concave to sinuous clypeus.

Worker measurements (n=9). HW 0.82–0.96, HL 0.84–0.99, EL 0.17–0.19, PMH 0.33–0.41, PH 0.29–0.39, PNH 0.23–0.27, LHW 0.51–0.59, EW 0.10–0.12, PML 0.57–0.70, ML 0.96–1.15, PL 0.41–0.51, PNWdv 0.25–0.35.

Worker Description. Large species with a medium sized, rectangular head; posterior cephalic margin straight to shallowly concave. Anterodorsal margin of the clypeus shallowly concave or sinuous with frontolateral carinae present as raised ridges that do not extend anteriorly beyond anteroventral clypeal margin; anteroventral margin without a small median projection, margin appears straight. Frons strigate, strigae extending well above antennal lobes; coarse lateral cephalic strigae reach anterior eye margin. Eyes medium, EW 0.20–0.23 x LHW, ommatidia in longest vertical axis 11, maximum in longest horizontal axis 9–10. Antennal scapes with paired erect hairs dorsally that are approximately twice as long as those on ventral surface.

Mesonotum rugulose/strigate on lateral curvature and in metanotal groove, smooth medially; promesonotal suture present in many specimens as a faint punctate line; posterior mesonotum with faint strigulae or smooth, appears raised with a horseshoe shaped margin in many specimens or may be flat and contiguous with surrounding surface. Mesopleuron alveolate with a few strigae extending anteriorly from metanotal groove. Propodeum in lateral view with dorsolateral angles almost forming a right angle; posterior margin appears vertical, propodeum appears cuboid; laterally alveolate with strigae extending over metapleural gland bulla and curving from dorsal half of metanotal groove onto dorsal surface and in posterodorsal corner. Dorsal surface of propodeum with transverse anterior carina prominent, transverse strigae present, longitudinal carinae present, converging anteriorly, most specimens with obvious concavity between posterolateral corners. Petiole node broad, more than 2.5x eye width when viewed from above; shape in posterior view tapering from broad midline to rounded apex; in lateral view anterior and posterior faces sub parallel, apex broadly rounded from higher anterior face to lower posterior face. Petiole node and postpetiole finely reticulate, sculpture not extending on to dorsal surface. T1 finely reticulate, sculpture covering at least anterior half of surface.

Head and mesosoma light to dark amber orange, legs orange brown, petiole and postpetiole infuscated on dorsal half, metasoma predominantly dark brown on tergites, sternites orange, some specimens with T1 infused with orange at the juncture with the postpetiole. Hairs over entire body appear dull yellow.

Male Measurements (n=3). HW 1.48–1.52, HL 1.01–1.07, EW 0.33, EL 0.50–0.52, ML 2.63–2.73, PeH 0.59–0.6, PNWdv 0.57–0.59, PPH 0.55.

Male Description. Head triangular with three ocelli. Eyes large, bulbous, oval in shape and positioned at an angle in lateral view such than longest axis point towards nearest lateral ocellus. Clypeus raised and rounded centrally, anterior margin straight. Mandibles with large apical tooth and two smaller teeth. Antennal scapes short, not surpassing dorsal eye margin. Sculpture coarsely rugose over entire surface.

Mesoscutum in profile evenly convex from anterior to posterior margin, sculpture rugose tending towards rugulose-strigate anteriorly except for a narrow triangle that runs centrally from anterior margin to center which is finely reticulate. Parapsidal lines present. Pronotum reticulate with strigae around dorsal margin. Scutellum large a bulbous with a central depression, sculpture rugulose. Mesopleuron and propodeum reticulate with strigulae extending over posterior half of mesopleuron and lateral surface of propodeum. Petiole and postpetiole with a flattened dorsal surface in lateral view, in dorsal view with a small median depression giving a slightly bilobed appearance sculpture reticulate, petiole only slightly taller than postpetiole.

Metasomal tergites and sternites finely reticulate over entire surface.

Colour black except antennal sclerite and pedicel, tarsi and posterior margins of tergites brown. Head mesosoma and ventral surface of legs and metasomal with large numbers of long, erect brown setae except for central triangle on mesoscutum which is glabrous.

Distribution. This species is known from the far north of the Northern Territory (see Remarks section under M. geminum sp. nov.). Its range overlaps with M. geminum sp. nov., M. hertogi sp. nov., M. hoffmanni sp. nov., M. kidman sp. nov., M. maryannae sp. nov. and M. stagnum sp. nov.

Additional material examined: see under M. geminum sp. nov..

Etymology. The specific name is a noun in apposition and refers to the region of the Northern Territory where this species has been collected.

Remarks. See comments under M. geminum sp. nov..

COI sequences. Genbank accession numbers for this species are KC572864 – KC572866 , KC572925 , KC572926 , KC573017 , KC573018 , KC573020 , KC573025 and KC573026 .

Figures

FIGURE 8. Workers of the M. rothsteini (Forel) species complex in lateral, head and dorsal view of the mesosoma. Fig. 8 a – c: M. tenebrosum, holotype (10 km N Tom Price, WA, KSS 177), d – f: M. topend, holotype (Darwin, NT, TERC 75), g – i: M. torrens, paratype (Flinders Rangers, SA, KSS 4). Scale bars are 0.5 mm for all views.