Systematics of the Monomorium rothsteini Forel species complex (Hymenoptera: Formicidae), a problematic ant group in Australia
Author
Sparks, Kathryn S.
South Australian Museum, North Terrace, Adelaide SA 5000, and Australian Centre for Evolutionary Biology and Biodiversity, and School of Earth & Environmental Sciences, The University of Adelaide, 5005, Australia
kate.sparks@samuseum.sa.gov.au
Author
Andersen, Alan N.
CSIRO Land and Water Flagship, Tropical Ecosystems Research Centre, PMB 44 Winnellie, NT 0822, Australia
Alan.Andersen@csiro.au
Author
Austin, Andrew D.
Australian Centre for Evolutionary Biology and Biodiversity, and School of Earth & Environmental Sciences, The University of Adelaide, 5005, Australia
andy.austin@adelaide.edu.au
text
Zootaxa
2014
2014-12-10
3893
4
489
529
journal article
42037
10.11646/zootaxa.3893.4.2
c50b4017-beb6-4783-820e-8a1da797f2d9
1175-5326
252022
65D00761-21AC-4B5D-ACB9-7BFFC69A75FC
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.
FIGURE 4.
Workers of the
M. rothsteini
(Forel)
species complex in lateral, head and dorsal view of the mesosoma. Fig. 4a–c:
M. bogischi
,
(Port Wakefield, SA, KSS241), d–f:
M. broschorum
holotype (Dajarra, QLD, KSS60), g–i:
M. capeyork
, holotype (69km N Archer River Roadhouse, QLD, TERC4), j–l:
M. eremoides
,
holotype (9km E 80 mile Beach, WA, KSS89), m–o:
M. eremum
,
holotype (33 km N Barkley Homestead, NT, KSS77). Scale bars are 0.5 mm for all views.
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.