Melophorus bagoti Lubbock

Heterick, Brian E., Castalanelli, Mark & Shattuck, Steve O., 2017, Revision of the ant genus Melophorus (Hymenoptera, Formicidae), ZooKeys 700, pp. 1-420 : 122-126

Melophorus bagoti Lubbock

Melophorus bagoti Lubbock 1883: 52, pl. 2, figs 1-10.

Type. Syntype major worker without an original label [BMNH] (examined: AntWeb image of BMNH specimen BMNH(E)1016283, CASENT0903260).

Camponotus cowlei Froggatt

Froggatt, W. W. (1896). Honey ants. pp. 385-392 In: Spencer B (Ed.) Report on the work of the Horn Scientific Expedition to Central Australia. Melbourne: Melville, Mullen & Slade Part 2 Zoology. [p. 387 pl. 27] (combination as Melophorus cowlei by Wheeler 1908:388; combination as Camponotus (Myrmophyma) cowlei by Emery 1925:110; junior synonym of Melophorus bagoti by Clark 1930:22; combination and valid species as Camponotus cowlei by Taylor and Brown 1985:112).

Types. Syntype major workers (assumed) and queen on separate pins, without collection data [AMS]. [Not seen] Syntype worker(s), queen(s), male(s), Spencer Gorge, McDonnell Ranges, Northern Territory [museum unknown]. Rev. comb.

(Note. The material includes the discoloured head and pronotum of a major worker and a worker gaster that have been glued to a newish-looking card rectangle, but the gaster does not appear to belong to that pin as it is shining and new in appearance, and may not even be that species. All three ants are labeled with their caste, surname and initials of Froggatt and date (1895) (label 1), and the scientific name (' Camponotus cowlei Froggatt’) (label 2). There is no mention of the collection locality. A gelatin capsule holds broken fragments of legs.)

Other material examined.

New South Wales: 40 km NNW Louth, Lake Mere (Greenslade, P.J. M. ), 40 km NNW Louth, Lake Mere (Greenslade, P.J. M. ), CSIRO Lake Mere Field Station, north Louth (Bryannah, M. ), Sturt National Park (Greenslade, P.J. M. ). Northern Territory: 18 km E The Granites (Morton, S. & Greenslade, P.J. M. ), 25 km N Alice Springs (Shattuck, S.O.), 25 km SSW The Granites, Tanami Desert (Morton, S. & Greenslade, P.J. M. ), 35 km SW The Granites, Tanami Desert (Morton, S. & Greenslade, P.J. M. ), 28 km WbyS Docker River (Feehan, J.E.), Glen Helen (Shattuck, S.O.), 61.5 km E Kalkarindji (Heterick, B.E. [M220]), Avon Downs (Colles, D.H.), Barry Caves (Feehan, J.E.), Batchelor (Hill, G.F. [ANIC32-039541]), Ellery Ck., Big Hole, West Macdonnells NP (Shattuck, S.O. [ANIC32-029215]), Kings Creek Station (Donellan, S.), nr Limbunya turnoff (Heterick, B.E. [M224]), Mataranka (Greaves, T), Rabbit Flat near Tanami (Wearne, K), Ti Tree, 170km N Alice Springs (Hiddins, L.). Queensland: ‘Gumbardo’ (Beutel, T.), ‘Gumbardo’ (Beutel, T.), ‘Gumbardo’ (Beutel, T.), ‘Gumbardo’ (Beutel, T.), Holts Creek, 8 km N Musselbrook Camp (Naumann, I. D.), ‘Merigol’ (Beutel, T.), ‘Merigol’ (Beutel, T.), Mica Creek, Mount Isa (Burwell, C. J.), 13 km from S-bend on Plum Pudding Track (Lemann, C. [ANIC32-035469]), 15 mi S Kamilaroi Homestead (Dowse, J.E.), Mt. Isa (Weatherill, L.). South Australia: 14.5 km W Wallatinna HS (Pitjantjatjara Lands Survey [M89/M105]), 18 mi W Mt. Morris (McInnes & Dowse), 25 mi W Mt. Morris (McInnes & Dowse). Western Australia: 10 km NE Woree Hill (Heterick, B.E. [M180/M181/M182]), 11 km E Willare Bridge (Heterick, B.E. [M246]), 12 mi N Wittenoom (McInnes & Dowse), 12 mi S Cardawan Homestead, SSW Mundiwindi (McInnes & Dowse [ANIC32-900069]), 14 km E Roebuck Plains RH (Heterick, B.E. [M187]), 150 km SW Giles Meteorological Station (Heatwole, H.), 16 km SbyW Onslow (Feehan, J.E.), 26 mi NE Paynes Find on Sandstone Road (Douglas, A. M. & M. J.), 27 km SE Newman (Britton, E.B.), 34 mi ENE Broome (McInnes & Dowse), 47 km E Fitzroy Crossing (Heterick, B.E. [M235]), 50 km N Carnarvon (Morton, S.R. [ANIC32-900070]), 56 mi WSW Mt. Gordon, Browne Range (McInnes, R. & Dowse, J.), 68 km S Newman (Britton, E.B.), 70 km N Halls Creek (Heterick, B.E. [M211]), 74 km EbyN Cosmo Newberry (Feehan, J.E.), 85 km E Meentheena OC (CALM Pilbara Survey [JDM32-004588]), Alpha Is., Monte Bello Islands (Campbell, T.G. [ANIC32-039538]), Argyle Diamonds via Kununurra (Postle, A.T. [JDM32-004532]), Broome (Weatherill, L.), Derby (Campbell, J.G.), Derby (Marchant [JDM32-004536]), Garden Well, 9 km SWbyS Mt. Phoenix (Feehan, J.E.), Jigalong (Hickmer, J.), Little Sandy Desert (Guthrie N. A. [M143]), Marillana Station (Dunlop, J.N. [JDM32-004535]), Nita Downs turnoff (Heterick, B.E. [M262]), Tropicana Minesite (Summerhayes, J. [JDM32-004587]), Well 31, Canning Stock Route between Meekatharra and Billiluna Pool [Collector unknown], Willare Bridge (Heterick, B.E. [M190]), Willie Creek turnoff (Heterick, B.E. [M276]), Windjana Gorge National Park (Ward, P.S.).

Diagnosis.

Melophorus bagoti is a member of the M. aeneovirens species-group (in full-face view, the anterior clypeal margin convex, apron-like and covering whole or part of the retracted mandible, except in M. nemophilus , the medial clypeal sector often produced so that it is protrusive when seen in profile; the psammophore frequently with coarse and well-separated ammochaetae, these always placed on or just above anterior margin; in profile, the propodeum elongate and oblique or broadly rounded). The ant is also placed as a member of the M. bagoti complex because of the acuminate appearance of the midpoint of the anterior clypeal margin. In full-face view, the psammophore occurs as a row of long, thick setae set slightly above the anterior clypeal margin. Melophorus bagoti has five rows of preapical tibial spines on the metatibia, and this distinguishes it from its sister, M. gracilipes , and all other Melophorus .

Minor worker description.

Head. Head square or rectangular, tending to trapezoid; posterior margin of head extended posteriad as a convex, sloping surface with a slight medioccipital protuberance; frons shining with superficial shagreenation or microreticulation only; frons consisting exclusively or almost exclusively of well-spaced, appressed setae only (small, erect setae, if present, usually confined to ocular triangle or posterior margin of head). Eye moderate (eye length 0.20-0.49 length of side of head capsule); in full-face view, eyes set above midpoint of head capsule; in profile, eye set anteriad of midline of head capsule; eyes elliptical or slightly reniform. In full-face view, frontal carinae straight or weakly convex; frontal lobes straight in front of antennal insertion. Anteromedial clypeal margin convex, weakly acuminate anteromedially; clypeal psammophore set at or just above anterior clypeal margin; palp formula 6,4. Five to six mandibular teeth in minor worker; mandibles triangular, weakly incurved; third mandibular tooth distinctly shorter than apical tooth and teeth numbers two and four; masticatory margin of mandibles approximately vertical or weakly oblique. Mesosoma. Integument of pronotum, mesonotum and mesopleuron uniformly shagreenate to moderately shining and shagreenate throughout; anterior mesosoma in profile broadly convex; erect pronotal setae absent; in profile, metanotal groove shallow, broadly V or U-shaped; propodeum shining and shagreenate; propodeum smoothly rounded or with indistinct angle or bluntly angulate; length ratio of propodeal dorsum to its declivity about 2:1; propodeal dorsum and declivity confluent; erect propodeal setae always absent; appressed propodeal setulae short, separated by more than own length and inconspicuous; propodeal spiracle situated at least twice its width from the declivitous face of propodeum, and shorter (length <0.50 × height of propodeum). Petiole. In profile, petiolar node a broadly right-angled triangle, node with steeply declivitous posterior face; in full-face view, shape of petiolar node uniformly rounded; node shining and smooth throughout. Gaster. Gaster smooth and glossy or shining, shagreenate ('LP record’ appearance); pilosity of first gastral tergite consisting of well-spaced short, inconspicuous, appressed setae, erect setae (present in at least some workers) confined to margin of sclerite. General characters. Colour mostly uniformly deep orange, but some workers with foreparts and appendages orange, and gaster black with blue-green iridescence.

Major worker description.

Head. Head horizontally rectangular, broader than wide; posterior margin of head planar or weakly convex; cuticle of frons ranging from matt or with weak sheen, indistinctly shagreenate through to shining with superficial shagreenation or microreticulation; pilosity of frons a mixture of a few well-spaced, erect setae interspersed with appressed setae only. Eye moderate (eye length 0.20-0.49 length of head capsule); in full-face view, eyes set above midpoint of head capsule; in profile, eye set anteriad of midline of head capsule; eyes elliptical. In full-face view, frontal carinae straight or weakly convex; frontal lobes straight in front of antennal insertion. Anterior clypeal margin convex, acuminate anteromedially, margin entire; clypeal psammophore set at or just above anterior clypeal margin; palp formula 6,4. Five to six mandibular teeth in major worker; mandibles triangular, weakly incurved; third mandibular tooth distinctly shorter than apical tooth and teeth numbers two and four; masticatory margin of mandibles approximately aligned vertically or weakly oblique. Mesosoma. Integument of pronotum, mesonotum and mesopleuron moderately shining and shagreenate throughout; anterior mesosoma in profile broadly convex; erect pronotal setae long (i.e., longer than length of eye) and unmodified; in profile, metanotal groove shallow, broadly V- or U-shaped; propodeum shining and shagreenate, or matt or with a weak sheen and microreticulate; propodeum angulate, propodeal angle blunt; length ratio of propodeal dorsum to its declivity between 3:2 and 4:3; erect propodeal setae absent; appressed propodeal setae short, separated by more than own length and inconspicuous; propodeal spiracle situated at least twice its width from the declivitous face of propodeum, and shorter (length less than 0.50 × height of propodeum). Petiole. In profile, petiolar node a broadly right angled triangle, node with steeply declivitous posterior face; in full-face view, shape of petiolar node generally rounded with median indentation; node shining and faintly shagreenate-microreticulate. Gaster. Gaster shining, shagreenate ('LP record’ appearance); pilosity of first gastral tergite consisting of well-spaced short, inconspicuous, appressed setae, erect setae (present in at least some workers) confined to margin of the sclerite. General characters. Colour as for minor worker.

Measurements.

Worker (n = 8): CI 99-118; EI 16-22; EL 0.30-0.52; HL 1.41-2.81; HW 1.39-3.33; ML 2.66-4.59; MTL 1.91-3.01; PpH 0.32-0.47; PpL 1.23-1.73; SI 81-147; SL 2.04-2.71.

Comments.

Melophorus bagoti is the Melophorus with which the average layperson from the drier rural areas is probably best acquainted because of its bright colour and its size. The size alone makes this species unmistakable except for M. gracilipes , from which it can be distinguished by the presence of five rows of tibial spurs (compared with the normal two rows in the latter species). Melophorus bagoti has been recorded from all mainland Australian states except Victoria, but appears to be most common in the NT and WA. A number of samples of the taxon have been sequenced, and these reveal a monophyletic group (see above discussion of the complex).

Syntype specimens (at least two) for ' Camponotus cowlei ' have been seen. Although very badly damaged, sufficient of the ants remain, including the all-important head capsule and spinous tibiae, for the identity of the species not to be in doubt. ' Camponotus cowlei ' therefore reverts to its previous synonym under the genus Melophorus .

As discussed in the Introduction, this ant has been the focus of a number of studies that look at orientation in desert ants, but its thermophilic aspects and nest structure have also gained attention (see references in the Introduction): along with Melophorus perthensis , this is the best known and most thoroughly researched Melophorus . In drier regions M. bagoti workers are frequently seen scurrying rapidly over the ground surface foraging for seeds and carrion. In the Kimberley, the principal author also saw many workers climbing over a small shrub when it was in flower, seeking nectar.