Monomorium bogischi Wheeler 1917

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 : 497-500

Monomorium bogischi Wheeler 1917 stat. rev., stat. nov.

( Fig. 4 a–c, 9a–f, 11a)

Monomorium subapterum var. bogischi Wheeler, 1917:112 .

Syntypes, 1 queen and 4 workers, South Australia, Port Wakefield, G.P. Bogisch ( MCZ). One worker (bottom point on a pin with two other workers) here designated as lectotype. The other 4 specimens here designated as paralectotypes.

Chelaner subapterum bosischi (Wheeler) ; Ettershank, 1966: 97.

Monomorium subapterum bogischi Wheeler ; Bolton, 1987: 300–301.

Monomorium rothsteini Forel ; synonymy by Heterick, 2001: 408.

Diagnosis. A small, glossy, brown species with a sinuous to straight anterodorsal margin of the clypeus, smooth mesonotum and a narrow petiole node.

Worker measurements (n=9). HW 0.64–0.88, HL 0.70–0.92, EL 0.14–0.19, PMH 0.25–0.31, PH 0.21–0.25, PNH 0.16–0.2, LHW 0.41–0.57, EW 0.10–0.12, PML 0.41–0.55, ML 0.7–0.92, PL 0.31–0.39, PNWdv 0.16–0.23.

Worker Description. Small species with a small rectangular head; posterior cephalic margin broadly and shallowly depressed to broadly V shaped. Clypeus anterodorsal margin sinuous to almost straight, frontolateral carinae forming smooth ridges; anteroventral margin of the clypeus without a small median projection, margin appears straight. Sculpture on frons limited to a few strigae present only on antennal lobes; coarse lateral cephalic strigae not reaching anterior eye margin, a few very fine strigae may reach margin. Eyes large, EW> 0.23 x LHW, 12–13 ommatidia in longest vertical axis, 10 in longest horizontal axis.

Mesonotum smooth and shining, a few strigulae on posterior mesonotum. Mesopleuron alveolate with a few strigae extending from metanotal groove to promesonotal suture on dorsal half. Propodeum in lateral view with dorsolateral angles clearly forming an obtuse angle, sculpture alveolate with strigae extending over metapleural gland bulla and almost reaching metanotal groove; dorsal surface with anterior transverse carina weekly present, transverse and longitudinal strigae absent, posterolateral angles rounded on dorsal half. Petiole node narrow, less than 2 x eye width when viewed from above, shape in posterior view tapered to narrowly rounded point when viewed laterally with anterior and posterior faces converging to narrowly rounded dorsum. Petiole node without sculpture, postpetiole with fine reticulate sculpture laterally and along posterior basal margin. T1 completely smooth and shining, without sculpture.

Head and mesosoma light to dark brown with a reddish-orange tinge, petiole and postpetiole somewhat darker, legs dark brown, metasoma dark brown.

Queen measurements (n=3). HW 1.38–1.52, HL 1.25–1.35, EW 0.21–0.25, EL 0.29–0.33, ML 2.38–2.55, PeH 0.68–0.70, PNWdv 0.49–0.51, PPH 0.53–0.59.

Queen description. Head triangular, broader behind the eyes that in front, vertex straight sculpture strigulate on antennal lobes, almost reaching median ocellus, remainder of frontal area smooth, laterally irregularly strigulate. Frontal clypeal margin straight to very mildly concave. Mandibles strigate with a large apical and two smaller preapical teeth. When angled towards eye antennal scapes not surpassing dorsal eye margin.

Mesoscutum in profile evenly rounded from pronotum to scutellum, scutellum rounded and raised only slightly above surface of mesoscutum, surface smooth and shining except for pitted setal insertion points. Pronotum, mesopleuron and propodeum finely reticulate, dorsal half of mesopleuron above central groove almost smooth. Propodeum with a series of parallel ridges on ventral margin of lateral surface that curve onto posterior surface. Petiole node triangular in profile, rounded in posterior view, petiole and postpetiole alveolate to reticulate, petiole laterally with transverse ridges on ventral half, postpetiole with irregular ridges on lateral and posterior surfaces. Metasomal tergites and sternites finely reticulate.

Colour entirely reddish-brown, metasomal tergites with a darker band along posterior margins. Head and mesosoma with many long and short, erect, dull setae except for a broad glabrous area that spans entire length of mesoscutum.

Distribution. This species is known from the south east corner of South Australia and the south west corner of Queensland.

Remarks. Wheeler (1917) proposed the names M. subapterum and M. subapterum var. bogischi as part of a discussion on the origins of aptery and subaptery stating that he would describe them “elsewhere”. No subsequent formal description of these forms occurred in the literature, but as brief morphological criteria are provided to distinguish M. subapterum from ‘ M. rothsteini var. humilius’ in Wheeler (1917), this is sufficient information to validate the names under the International Code of Zoological Nomenclature.

The queen description here is based solely on the paralectotype available. Two other queens found in a nest near Birdsville in the south west of Queensland show some morphological differences. In particular, the colour of the paralectotype is pale reddish brown ( Fig. 9 a–c), whereas the Birdsville specimens are a dark crimson brown ( Fig. 9 d–f). In addition the paralectotype has fine reticulate sculpture on the ventral half of the mesopleuron and the propodeum whereas the Birdsville specimens are strigate in these areas. The Birdsville specimens have a broad, glabrous area that spans the length of the mesoscutum, this area is much narrower in the paralectotypes. The worker lectotype and paralectotypes are indistinguishable from those that were freshly collected from the type locality and those from the type locality were found to have an identical COI sequence to the workers collected near Birdsville ( Sparks et al. 2014). The two populations are more than 900km apart, and therefore it is not unreasonable to expect that morphological differences exists across such a distance. However it is also possible that the two populations represent different species that we are currently unable to detect. The workers of M. bogischi are very difficult to separate from M. torrens sp. nov., M. subapterum Wheeler , and M. speculum sp. nov., but can be distinguished from these by the presence of a prominent anterior transverse carina on the propodeum.

COI sequences. Genbank accession numbers for this species are KC572927 , KC572929 –572931 and KC572999 –573000.

Additional material examined. (QM, SAM) Queensland: E of Birdsville, -25.8730, 139.4671, 2 Jun 2009, K.S. Sparks, KSS45; KSS46; KSS47; South Australia: Karoonda-Perponda Rd, -34.9751, 139.9088, 9 Mar 2009, K. Sparks, KSS26; Port Wakefield, -34.1665, 138.1481, 12 Mar 2011, K. Sparks, KSS238; KSS239; KSS240; KSS241.

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 9. Queens and males of the M. rothsteini (Forel) species complex in lateral, head and dorsal view of the mesosoma. Fig. 9 a – c: M. bogischi queen (light form), paralectotype (Port Wakefield. SA), d – f: M. bogischi queen (dark form) (Birdsville, QLD, KSS 46), g – i: M. humilior queen, paralectotype (Tennant Ck, NT), j – l: M. humilior male (Tennant Creek, NT), m – o: M. subapterum queen, paralectotype (Harding River, WA). Scale bars are 1 mm for all views.