Melophorus aeneovirens

Melophorus aeneovirens was the first Melophorus species to be described, and is among the most common of all the Melophorus species.

Identification
Heterick et al. (2017) - Melophorus aeneovirens 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 Melophorus 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), and the M. aeneovirens species-complex (in full-face view, psammophore ranged along or just above anterior margin of clypeus and following the curve of the margin; anterior margin of clypeus broadly medially produced, and often with central notch that may be deeply impressed, but is never acuminate at its midpoint; metatibia with maximum of two rows of preapical spines). In M. aeneovirens the tibiae possess stout, socketed, appressed to subdecumbent setae only, with fine, appressed pubescence lacking. In profile, the minor worker mesosoma is compact and is arcuate in outline. Melophorus aeneovirens can be distinguished from similar species by having, in profile, the clypeus distinctly recurved at about midpoint and produced over the mandible as a small ledge; in full-face view, the anterior margin of the major and minor worker clypeus forms a broadly convex, sometimes crenulate curve that does not protrude over apical the curve of mandible.

In general, there is some morphological variation, particularly among minor workers. Colour varies from orange to blackish-brown among minor workers and the degree of compression of the dorsum of the propodeum also varies: in some cases this sclerite is rather convex in outline but it can be straight or even fractionally concave. The metanotal groove varies from deeply to weakly incised. Minor workers among different populations can also vary markedly in size and sculpture. However, all minor workers share the recurved appearance of the clypeus when this is seen in profile, an asymmetrical vertex (like Melophorus praesens and Melophorus rufoniger) and an anterior clypeal margin that is never strongly produced so as to form a ledge (this feature serves to separate M. aeneovirens from nearly all other members of the M. aeneovirens species-group).

Distribution
Heterick et al. (2017) - Found in all mainland states. This ant is particularly common on the eastern seaboard, but does not appear to occur in Tasmania. The distribution of this taxon is predominantly southern and most collections have been taken in mesic, coastal localities, with far fewer records from arid and semi-arid areas.

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Biology
Heterick et al. (2017) - This is the common Melophorus species taken in well-watered forests. Lowne (1865) mentions this ant formed small nests with an inconspicuous opening, and nests in Port Jackson NSW (the type locality) were usually concealed under leaves or stones. The habits of M. aeneovirens may well be mentioned in the literature without the species being identified, but little has been recorded under that name or under the synonymic names. Since this species occurs in a very wide range of habitats, including grassy lawns of suburban residences, the most logical inference is that it is a generalized scavenger.

Nomenclature

 *  aeneovirens. Formica aeneovirens Lowne, 1865a: 276 (s.w.) AUSTRALIA.
 * Combination in Cataglyphis: Mayr, 1876: 78
 * Combination in Melophorus: Forel, 1902h: 488.
 * Senior synonym of constans, fraudatrix, froggatti, insularis, iridescens: Heterick, Castalanelli & Shattuck, 2007: 75-76.
 * constans. Melophorus constans Santschi, 1928e: 475 (w.q.) AUSTRALIA.
 * Junior synonym of aeneovirens: Heterick, Castalanelli & Shattuck, 2007: 75.
 * insularis. Melophorus insularis Wheeler, W.M. 1934d: 151 (s.w.) AUSTRALIA.
 * Junior synonym of aeneovirens: Heterick, Castalanelli & Shattuck, 2007: 75.
 * iridescens. Myrmecocystus iridescens Emery, 1887a: 247 (w.) AUSTRALIA.
 * Combination in Melophorus: Forel, 1902h: 487.
 * Junior synonym of aeneovirens: Heterick, Castalanelli & Shattuck, 2007: 75.
 * fraudatrix. Melophorus iridescens var. fraudatrix Forel, 1915b: 87 (footnote) (w.) AUSTRALIA.
 * Subspecies of iridescens: Taylor & Brown, D.R. 1985: 123.
 * Junior synonym of aeneovirens: Heterick, Castalanelli & Shattuck, 2007: 76.
 * froggatti. Melophorus iridescens var. froggatti Forel, 1902h: 487 (s.w.q.) AUSTRALIA.
 * Subspecies of iridescens: Forel, 1907a: 29.
 * Junior synonym of aeneovirens: Heterick, Castalanelli & Shattuck, 2007: 75.

Worker
Heterick et al. (2017) - (n = 6): CI 91–115; EI 14–28; EL 0.19–0.34; HL 0.73–2.12; HW 0.67–2.44; ML 1.15–2.47; MTL 0.60–1.39; PpH 0.13–0.25; PpL 0.61–1.15; SI 67–142; SL 0.95–1.62.

Minor. Head. Head square; posterior margin of head strongly 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 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 concave; frontal lobes straight in front of antennal insertion. Anteromedial clypeal margin narrowly convex and protruding, clypeal margin entire or very weakly indented, or narrowly convex and protruding anteromedially, clypeal midpoint distinctly notched; clypeal psammophore set at or above midpoint of clypeus; 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 moderately shining and shagreenate throughout; anterior mesosoma in profile broadly convex; erect pronotal setae absent; in profile, metanotal groove deep, ‘V’-shaped; propodeum shining and shagreenate; propodeum smoothly rounded or with indistinct angle; propodeal dorsum and declivity confluent; erect propodeal setae always absent; appressed propodeal setulae long and closely aligned, creating pubescence; 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 subcuboidal, vertex bluntly rounded; in full-face view, shape of petiolar node generally rounded with median indentation or hollow; node shining and distinctly shagreenate-microreticulate. Gaster. Gaster weakly shining with indistinct shagreenation; pilosity of first gastral tergite consisting of long, closely aligned, whitish, appressed setae, with erect setae (present in at least some workers) confined to margin of sclerite. General characters. Colour of foreparts reddish-brown through red to dark crimson, legs dark brown, gaster blackish-brown to black.

Major. Head. Head quadrate (i.e., heart-shaped); posterior margin of head strongly concave; cuticle of 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 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 concave; frontal lobes straight in front of antennal insertion. Anterior clypeal margin narrowly convex and protruding anteromedially, clypeal margin entire or weakly indented; 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 short (i.e., shorter than length of eye) and unmodified; in profile, metanotal groove shallow, broadly V- or U-shaped; propodeum shining and shagreenate; propodeum smoothly rounded or with indistinct angle; propodeal dorsum and declivity confluent; erect propodeal setae present and abundant (at least a dozen); appressed propodeal setae long and closely aligned, creating pubescence; 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 squamiform; in full-face view, shape of petiolar node uniformly rounded; node shining and faintly shagreenate-microreticulate. Gaster. Gaster weakly shining with indistinct shagreenation; pilosity of first gastral tergite consisting of well-spaced short, inconspicuous, appressed setae only, erect setae always absent. General characters. Colour of foreparts reddish-brown through red to dark crimson, legs dark brown, gaster blackish-brown to black.