Melophorus major

Melophorus major
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Formicinae
Tribe:	Melophorini
Genus:	Melophorus
Species group:	biroi
Species complex:	fieldi
Species:	M. major
Binomial name
	Melophorus major; Forel, 1915 Specimen labels

Nothing is known about the biology of Melophorus major.

Identification

Heterick et al. (2017) - Melophorus major can be placed in the Melophoprus biroi species-group on the basis of characters of the clypeus, propodeum, mandible and palps. The species is also placed in the Melophoprus fieldi species-complex because of the appearance of the anteriorly placed clypeal psammophore, the compact propodeum, the presence of more than one preapical spine on the metatibia, at least in the major worker, the long, even spindly legs, and the unmodified mandible in the major worker. The large-eyed Melophorus major closely resembles several related Melophorus, most obviously Melophorus bruneus, Melophorus fieldi and the Melophorus turneri candidus form of Melophorus turneri. The one distinctive feature that places at least the M. major minor worker apart from other Melophorus in its species-complex is the low placement of the clypeal psammophore: in profile, this structure is to be found just behind the anterior clypeal margin and it is also placed well below the midpoint of the clypeus in some major workers. At present the few known major workers cannot be separated with any confidence from related species or populations of species with an anteriorly situated psammophore, but the propodeum is narrow with an oblique dorsal face and the colour of major workers seen is shining brown with the gaster slightly darker, and this character may be helpful in some cases.

Apart from the low placement of the clypeal psammophore, this medium-sized Melophorus is completely unremarkable and can easily be mistaken for Melophorus inconspicuus or a dark Melophorus hirsutipes, to which it is likely closely related.

The name ‘major’ is given new species level status in this revision. The syntypes for this species (two separate pins available for specimen analysis and three Automontage photographs on AntWeb) reveal a few small differences from the remaining material; namely, the eye in the non-type material (both major and minor workers) is larger and the erect pilosity is longer and a little more extensive. These differences may be explained by biogeography, the type specimens having been collected in the Kimberley (not shown on the map because of the vagueness of the collection locality), and the others much further south. The media worker available for inspection, however, has the same protuberant clypeus and anteriorly placed clypeal psammophore seen in the non-type minor workers. This feature is distinctive and is not seen in any other member of the M. fieldi complex. The major worker does not always share this feature and is difficult to separate from allied species. The dark colouration and short propodeum with an oblique dorsal face (compared with an often blocky, square propodeum in similar species) help in the identification of major workers, but minor workers are needed for identifications to be definitive.

Distribution

Heterick et al. (2017) - The range of Melophorus major is uncertain (because of the difficulty in separating this species, especially major workers, from several morphologically very similar taxa), but it is likely to occur sparsely in drier areas across the continent in suitable habitat.

Distribution based on Regional Taxon Lists

Australasian Region: Australia (type locality).

Distribution based on AntMaps

Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.

Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.

Biology

Castes

Worker

Images from AntWeb


Syntype of Melophorus major. Worker (major/soldier). Specimen code antweb1038574. Photographer Paige Maroni, uploaded by California Academy of Sciences.	Owned by MHNG, Geneva, Switzerland.


Syntype of Melophorus major. Worker (major/soldier). Specimen code antweb1038573. Photographer Paige Maroni, uploaded by California Academy of Sciences.	Owned by MHNG, Geneva, Switzerland.


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Phylogeny

Melophorus

	Melophorus ludius species group

	Melophorus potteri species group

Melophorus aeneovirens species group

Melophorus biroi species group (biroi species complex)

Melophorus biroi species group (wheeleri species complex)

	Melophorus biroi species group (brevignathus species complex)

	Melophorus biroi species group (fieldi species complex)

Based on Heterick et al., 2017. Only selected species groups/complexes are included.

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

major. Melophorus fieldi var. major Forel, 1915b: 87 (s.w.) AUSTRALIA.
- Subspecies of fieldi: Emery, 1925b: 12; Taylor & Brown, 1985: 123; Bolton, 1995b: 250.
- Status as species: Heterick, et al. 2017: 280 (redescription).

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Worker

Heterick et al. (2017) - (n = 2): CI 99–112; EI 23–37; EL 0.28–0.37; HL 0.76–1.45; HW 0.75–1.63; ML 1.07–1.71; MTL 0.69–1.08; PpH 0.12–0.16; PpL 0.43–0.71; SI 70–109; SL 0.82–1.14.

Minor. Head. Head square; posterior margin of head planar or weakly convex; frons shining with superficial shagreenation or microreticulation only; pilosity of frons a mixture of a few well-spaced, erect setae interspersed with appressed setae only. Eye large (eye length ≥ 0.50 × length of side of head capsule), or moderate (eye length 0.20–0.49 length of side of head capsule); in full-face view, eyes set at about 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 distinctly concave; frontal lobes straight in front of antennal insertion. Anteromedial clypeal margin broadly and evenly convex; clypeal psammophore set at or just above anterior clypeal margin; palp formula 6,4. Five 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 moderately shining and shagreenate throughout; anterior mesosoma in profile broadly convex; appearance of erect pronotal setae short, (i.e., longest erect setae shorter than length of eye) and unmodified; in profile, metanotal groove shallow, broadly V- or U-shaped; propodeum shining and finely striolate and microreticulate; propodeum angulate, propodeal angle blunt; length ratio of propodeal dorsum to its declivity greater than 2:1; erect propodeal setae variable in number, may be absent; appressed propodeal setulae short, separated by more than own length and inconspicuous; propodeal spiracle situated on or beside declivitous face of propodeum, and longer (length ≥ 0.50 × height of propodeum), or situated on or beside declivitous face of propodeum, and shorter (length < 0.50 × height of propodeum). Petiole. In profile, petiolar node squamiform; in full-face view, shape of petiolar node uniformly rounded; node shining and distinctly shagreenate-microreticulate. Gaster. Gaster shining, shagreenate (‘LP record’ appearance); pilosity of first gastral tergite consisting of well-spaced, erect and semi-erect setae interspersed with regularly placed appressed setae. General characters. Colour of foreparts brown, gaster blackish-brown.

Major. Head. Head square; posterior margin of head weakly concave; cuticle of frons shining with superficial shagreenation or microreticulation only; 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 at about midpoint of head capsule; in profile, eye set anteriad of midline of head capsule; eyes elliptical. In full-face view, frontal carinae straight, divergent posteriad; frontal lobes straight in front of antennal insertion. Anterior clypeal margin broadly and evenly convex; clypeal psammophore set at or just above anterior clypeal margin; palp formula 6,4. Five 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 short, (i.e., shorter than length of eye) and unmodified; in profile, metanotal groove shallow, indicated mainly by an angle and metathoracic spiracles; propodeum shining and shagreenate; propodeum angulate, propodeal angle blunt; length ratio of propodeal dorsum to its declivity between 1:1 and1:2, or greater than 1:2; erect propodeal setae present and abundant (at least a dozen); appressed propodeal setae long and separated by at least own length; propodeal spiracle situated on or beside declivitous face of propodeum, and longer (length ≥ 0.50 × height of propodeum). Petiole. In profile, petiolar node squamiform; in full-face view, shape of petiolar node uniformly rounded; node shining and faintly shagreenate-microreticulate. Gaster. Gaster shining with superficial microreticulation; pilosity of first gastral tergite consisting of well-spaced, erect and semi-erect setae interspersed with regularly spaced appressed setae. General characters. Colour of foreparts orange tan, gaster blackish-brown.

Type Material

Heterick et al. (2017) - Syntype major worker and minor workers: major and minor worker on separate pins, Kimberley district, Western Australia Musee d'Histoire Naturelle Genève. Also examined: MHNG, Museo Civico di Storia Naturale, Genoa, NHRS AntWeb images of specimens (MHNG specimens CASENT0909812, CASENT0909813, MSNG specimen CASENT0905126, NHRS specimen NHRSHEVA00003949).

Syntype, worker(s), Kimberley distr., Western Australia, Australia, Musee d'Histoire Naturelle Genève.

References

Forel, A. 1915b. Results of Dr. E. Mjöbergs Swedish Scientific Expeditions to Australia 1910-13. 2. Ameisen. Ark. Zool. 9(1 16: 1-119 (page 87, soldier, worker described)
Heterick, B.E. 2021. A guide to the ants of Western Australia. Part I: Systematics. Records of the Western Australian Museum, Supplement 86, 1-245 (doi:10.18195/issn.0313-122x.86.2021.001-245).
Heterick, B.E. 2022. A guide to the ants of Western Australia. Part II: Distribution and biology. Records of the Western Australian Museum, supplement 86: 247-510 (doi:10.18195/issn.0313-122x.86.2022.247-510).
Heterick, B.E., Castalanelli, M., Shattuck, S.O. 2017. Revision of the ant genus Melophorus (Hymenoptera, Formicidae). ZooKeys 700, 1–420 (doi: 10.3897/zookeys.700.11784).
Taylor, R. W.; Brown, D. R. 1985. Formicoidea. Zool. Cat. Aust. 2:1- 149: 1-149, 30 (page 123, Subspecies of fieldi)

References based on Global Ant Biodiversity Informatics

Forel A. 1915. Results of Dr. E. Mjöbergs Swedish Scientific Expeditions to Australia 1910-13. 2. Ameisen. Ark. Zool. 9(16): 1-119
Heterick B. E., M. Castalanelli, and S. O. Shattuck. 2017. Revision of the ant genus Melophorus (Hymenoptera, Formicidae). ZooKeys 700: 1-420.
Taylor R. W. 1987. A checklist of the ants of Australia, New Caledonia and New Zealand (Hymenoptera: Formicidae). CSIRO (Commonwealth Scientific and Industrial Research Organization) Division of Entomology Report 41: 1-92.