Monomorium eremoides 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 : 501-502

Monomorium eremoides Sparks , NEW SPECIES

( Fig. 4 j–l, 11b)

Holotype worker. Western Australia. 9km E 80 mile Beach, -19.8323, 120.6992, 14 Oct 2009, K.S. Sparks, C. Petit, KSS141 (deposited in WAM).

Paratypes. 10 workers, same data as holotype ; 10 workers, Northern Territory, Bimms Tk, 35km E Davenport Ra NP turnoff, -21.1089, 134.4806, 10 Jun 2009, K.S. Sparks, KSS89 (deposited in WAM, NTM, SAM).

Diagnosis. A large, very dark brown, glossy species with large eyes and a heavily sculptured mesonotum. This species cannot be separated morphologically from M. eremum sp. nov., but both M. eremoides and M. eremum sp. nov are two of the most distinctive species in the M. rothsteini complex and can be distinguished from all other species by combination of dark cuticular colour, sinuous clypeal margin and sculptured mesonotum.

Worker measurements (n=9). HW 0.78–0.74, HL 0.82–0.99, EL 0.2–0.21, PMH 0.27–0.35, PH 0.27–0.31, PNH 0.2–0.23, LHW 0.45–0.6, EW 0.12–0.14, PML 0.53–0.64, ML 0.9–1.05, PL 0.39–0.47, PNWdv 0.21–0.27.

Worker Description. Large species with a medium-sized, rectangular head, posterior cephalic margin mildly depressed centrally to almost straight. Anterodorsal margin of the clypeus sinuous to almost straight, frontolateral carinae forming smooth ridges; anteroventral margin without a small median projection, margin appears straight. Sculpture on frons limited to a few strigae only present on antennal lobes; coarse lateral cephalic strigae reach anterior margin of eye or if not reaching, with a few very fine strigae reaching eye margin. Eyes large and bulbous, EW> 0.23 x LHW, 15 ommatidia in longest vertical axis, 12 in longest horizontal axis.

Mesonotum strigate/rugose over most of surface posteriad of promesonotal suture; metanotal groove deep and broad. Mesopleuron alveolate, dorsally with strigae extending from metanotal groove to promesonotal suture. Propodeum in lateral view with dorsolateral angles almost forming a right angle; posterior margin appears vertical, propodeum appears long and rectangular; sculpture alveolate, laterally with strigae curving from metanotal groove on to dorsal surface, extending over metapleural gland bulla to metanotal groove and over posterior half; dorsally with longitudinal strigae mostly absent, posterodorsal corners prominent and diverging; posterolateral corners with sharp carinae that extend from propodeal lobe onto dorsal surface. Petiole node narrow, less than 2 x eye width when viewed from above; shape in posterior view tapering from widest point just below midline and narrowly rounded dorsally, in lateral view anterior and posterior faces converging to rounded point. Posterior surface of petiole node without sculpture, rarely with fine reticulation along basal posterior margin only, postpetiole with fine reticulation. T1 commonly smooth and shining, rarely with a very fine reticulate pattern covering most of surface

Dorsal surface of head and antennal scapes dark chestnut brown, ventral surface of head and area laterad of clypeus, mandibles and antennal flagellae light brown, mesosoma and legs dark brown although lighter than dorsal surface of head, metasoma very dark brown, almost black, cuticle with a high gloss.

Distribution. This species is known from only from the far west coast of Western Australia and the Davenport Ranges in the Northern Territory (see Remarks section). Its range overlaps with M. eremum sp. nov. and M. subapterum .

Etymology. The specific name refers to this species similarity to the species M. eremum sp. nov..

Remarks. Monomorium eremoides and M. eremum sp. nov. are separated based on mtDNA evidence presented in Sparks et al. (2014). M. eremoides has a disjunct distribution with one population found on the north west coast of Western Australia and one in central Australia. Monomorium eremum has a more continuous distribution that spans the northwestern and central deserts of Australia and together with M. subapterum is the most commonly found species in the complex in the arid centre of the country. The additional material examined is listed here and mapped in Fig. 11 b as attributed to either species.

COI sequences. Genbank accession numbers for this species are KC572947 and KC572966 .

Additional material examined for M. eremoides and M. eremum ( SAM, TERC). Northern Territory. Tilmouth Well, Tanami Rd, -22.8884, 132.5698, 12 Jun 2009, K.S. Sparks, KSS102 ; Tanami Rd, 30km N Tilmouth Well, -22.6386, 132.3649, 13 Jun 2009, K.S. Sparks, KSS104 ; 10km N Tennant Creek, -19.55 134.23, Nov 1995, B. Hoffmann ; Alice Springs, -23.7 133.88, Nov 1995, B. Hoffmann ; Attack Creek, -18.3 134.583, Nov 1995, B. Hoffmann ; Banka Banka, loam, -19.65 134.19, May 1997, J. Cusak ; 28km W Newcastle Waters St., -17.3013 133.1675, 16 Jul 2001, A.L. Hertog ; Ti Tree, -22.13 133.41, 13 Apr 1999, B. Hoffmann ; Central Tanami, 57km E Granites Mine, -20.5066 130.9044, 5 Aug 2001, A.L. Hertog ; Central Tanami, 178km W Tennant Creek, -19.0525 131.8638, 24 Jul 2001, A.L. Hertog ; Central Tanami, 42km W Wycliffe Well, -20.9255 133.8547, 13 Jul 2001, A.L. Hertog ; Chilla Well area, Tanami Desert, -21.5272 130.97, 5 Jun 2006, A. Hertog ; 75km E Yulara, -25.32 131.92, 18 Jan 1981, D. Agosti ; Davenport Ranges NP, Old Policeman’s Hut Waterhole, -20.753 135.1852, 30 May 2006, A. Hertog ; Western Australia. 9km E of 80 Mile Beach, -19.80457, 120.67626, 14 Oct 2009, E. Schluens ES6 ; same locality and date K. Sparks and C. Petit, KSS138, KSS139, KSS142 ; Kidson Track, Jupiter Well, - 20.1566 135.18, 2 Jul 2005, A. Hertog ; Damier Downs HS, -18.5086 123.4569, 20 Jul 2005, A. Hertog ; 38km W Dampier Downs HS, -18.4027 123.1105, 23 Jul 2005, A. Hertog ; 20km W Canning Cairn, Canning Stock Route, - 23.7536 122.2705, 1 Aug 2005, A. Hertog ; 50km E Jiggalong, -23.4511 121.2377, 29 Jul 2005, A. Hertog ; 80 mile Beach, -19.68 121.04, 19 Sep 1998, A.N. Andersen ; Canning Stock Route nr. Lake Disappointment, -23.4972 122.5491, 6 Apr 2005, A. Hertog ; Jupiter Well, Great Sandy Desert, -22.8761 126.5961, 16 Jun 2006, A. Hertog ; Lake Gregory handover site, Great Sandy Desert, -20.1811 127.5363, 9 Jun 2006, A. Hertog ; Halls Creek, -18.433 127.6275, 20 Jun 2004, A. Hertog.

Figures

FIGURE 4. Workers of the M. rothsteini (Forel) species complex in lateral, head and dorsal view of the mesosoma. Fig. 4 a – c: M. bogischi, (Port Wakefield, SA, KSS 241), d – f: M. broschorum holotype (Dajarra, QLD, KSS 60), g – i: M. capeyork, holotype (69 km N Archer River Roadhouse, QLD, TERC 4), j – l: M. eremoides, holotype (9 km E 80 mile Beach, WA, KSS 89), m – o: M. eremum, holotype (33 km N Barkley Homestead, NT, KSS 77). Scale bars are 0.5 mm for all views.

FIGURE 11. Geographic distributions of species in the M. rothsteini (Forel) complex: (a): • bogischi, ⋅ broschorum, ˔ capeyork, + hertogi; (b): • eremum, ˔ eremoides + eremum and eremoides; (c): • geminum, ˔ topend, + geminum and topend; (d): • humilior, ⋅ kidmani, ˔ leda, + maryannae; (e): • merepah, ⋅ mitchell, ˔ oodnadatta, + pilbara; (f): • rothsteini, ⋅ speculum, ˔ stagnum, + hoffmanni.