Melophorus andersenioides Heterick, Castalanelli & Shattuck

Heterick, Brian E., Castalanelli, Mark & Shattuck, Steve O., 2017, Revision of the ant genus Melophorus (Hymenoptera, Formicidae), ZooKeys 700, pp. 1-420 : 137-139

Melophorus andersenioides Heterick, Castalanelli & Shattuck sp. n.

Types.

Holotype minor worker (bottom ant) from 40 miles N of Warren, New South Wales, 23 December 1963, B.B. Lowery, red soil, ANIC ANTS VIAL 68.156 [ANIC32-900082] (ANIC). Paratypes: Major worker and minor worker on same pin as holotype (ANIC); 2 media and a minor worker from Grantham, Queensland, 24 January 1957, B.B. Lowery, dry sclerophyll, ANIC ANTS VIAL 68.209 (BMNH); 3 major workers, media worker and minor worker from Warwick, Queensland, 4 January 1966, B.B. Lowery, Red soil, hilly, sav. woodland, edge of I. detectus nest, morning, R28 (MCZ); minor worker and major worker from Grantham, Queensland, 24 January 1957, B.B. Lowery [ANIC32-900081] (QM); major worker from ROC lease, Eneabba, Western Australia, 10-16 April 1997, L. Bisevac/B.E.Heterick, Plot 77AS, pitfall traps [JDM32-002001] (WAM); 2 minor workers and major worker from Nerren Nerren Stn 27°00's, 114°32'e, Western Australia, 26 September-19 October 1994, M. S. Harvey/J. M. Waldock, NE4 wet pits, WAQM/CALM survey, Carnarvon Basin [JDM32-002002] (WAM).

Diagnosis.

Melophorus andersenioides is a member of the M. anderseni species-group (maxillary palp segments short [not reaching neck sclerite], narrow and ter minating in a subulate [awl-shaped] segment; PF 6,4; metatibial apical spur absent; in full-face view, masticatory margin of mandible strongly oblique with four teeth in known major workers [except chrysus ], and four to six teeth in minor worker). This species is distinguished from three other members of the group by having a thick, rectangular or quadrate petiolar node in the minor worker, the anterior margin of clypeus weakly convex, the clypeus folded back and not protrusive, the clypeal psammophore located at the midline of clypeus and in having the antennal scape of minor worker with many short, erect, bristly setae.

Minor worker description.

Head. Head square; posterior margin of head planar or weakly convex; frons shining with indistinct microsculpture that is most pronounced on lower surfaces; frons consisting of appressed pubescence, with many short, unmodified, erect setae. 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 broadly convex with anteromedial dimple; clypeal psammophore set at or above midpoint of clypeus; palp formula 6,4. Mandibular teeth in minor worker four to five; mandibles narrow, strap-like, internal and external margins parallel or nearly so; third mandibular tooth distinctly shorter than apical tooth and teeth numbers two and four, or distinctly shorter than apical tooth and tooth no. two, tooth no. four vestigial, or distinctly shorter than apical tooth, but equivalent in length to remaining teeth, or absent; masticatory margin of mandibles strongly 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 a weak or vestigial furrow; propodeum shining and shagreenate; propodeum angulate, propodeal angle blunt; length ratio of propodeal dorsum to its declivity about 1:1; erect propodeal setae present and abundant (greater than 12); appressed propodeal setulae long and closely aligned, creating pubescence; propodeal spiracle situated nearer to midpoint of propodeum than to its declivitous face, and shorter (length <than 0.50 × height of propodeum). Petiole. In profile, petiolar node cuboidal, rounded above; in full-face view, shape of petiolar node uniformly rounded; node shining and distinctly shagreenate-microreticulate. Gaster. Gaster shining with superficial microreticulation; pilosity of first gastral tergite consisting of thick, appressed setae that form pubescence, interspersed with numerous short, bristly, erect setae. General characters. Colour brownish-orange to dark russet.

Major worker description.

Head. Head horizontally rectangular, broader than wide; posterior margin of head planar or weakly concave; cuticle of frons shining and smooth except for piliferous pits; frons consisting of appressed pubescence, with many short, unmodified, erect setae. Eye moderate (eye length 0.20-0.49 length of head capsule); in full-face view, midpoint of head capsule; in profile, eye set anteriad of midline of head capsule; eyes elliptical. In full-face view, frontal carinae distinctly concave; frontal lobes curved toward antennal insertion. Anterior clypeal margin broadly convex with anteromedial dimple; clypeal psammophore set at or above midpoint of clypeus; palp formula 6,4. Four to five mandibular teeth in major worker; mandibles narrow, strap-like, internal and external borders parallel or nearly so; third mandibular tooth distinctly shorter than apical tooth and teeth numbers two and four; masticatory margin of mandibles strongly oblique. Mesosoma. Integument of pronotum, mesonotum and mesopleuron shining with indistinct microsculpture that is most pronounced on lower surfaces; anterior mesosoma in profile steeply rounded anteriad, thereafter pronotum and whole of mesonotum flattened and on a higher plane than propodeum; 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 generally smooth, with only weak indistinct shagreenation; propodeum angulate, propodeal angle blunt; length ratio of propodeal dorsum to its declivity between 1:1 and 1:2; erect propodeal setae present and abundant (at least a dozen); appressed propodeal setae long and closely aligned, creating pubescence; propodeal spiracle situated on or beside 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 tapered with blunt vertex; node shining and smooth with vestigial microreticulation anteriad. Gaster. Gaster weakly shining with indistinct shagreenation; pilosity of first gastral tergite consisting of thick, appressed setae that form pubescence, interspersed with numerous short, bristly, erect setae. General characters. Colour brownish-orange.

Measurements.

Worker (n = 5): CI 104-127; EI 18-25; EL 0.25-0.31; HL 0.97-1.36; HW 1.00-1.74; ML 1.60-2.04; MTL 1.56-1.40; PpH 0.19-0.23; PpL 0.64-0.84; SI 72-136; SL 1.25-1.37.

Comments.

This ant has the species-group level characters of the previous taxon, but differs from it in the form of the clypeus (not protrusive in this species) and its greater hairiness. Melophorus andersenioides has a wider distribution than the foregoing (being found in NSW, QLD and WA), and has been collected in red soil. Label notes on two pins associate it with nests of Iridomyrmex purpureus (as ' I. detectus ', its junior synonym), and it is altogether possible that M. andersenioides is a social parasite on that species analogously with its relation.

Etymology.

anderseni (see above) plus Greek -oides ( ‘resembling’).