Melophorus potteri

Described from Victoria, where these ants are known to prey on termites (McAreavey 1947). Records from the SWBP have come from Eneabba, Kellerberrin and West Arthur in the central wheatbelt, but the ant appears to be more common north of the SWBP. (Heterick 2009)

Identification
Heterick et al. (2017) - Melophorus potteri is one of three members of the M. potteri species-group. Like the other two species, M. potteri has a large, oblique propodeal spiracle situated well before the declivitous face of propodeum, the spiracle bisecting much of the propodeum. This species is distinguished from the remaining members of the group by a combination of its glossy general appearance, its reduced palp formula (PF 3,4), its square or rectangular head capsule, the square protrusion of the anterior clypeal margin and the distally expanded basal margin of the mandible.

As with the closely related Melophorus pelecygnathus, Melophorus potteri is a highly distinctive species that cannot be mistaken for any other Melophorus. The mandibles are securiform with the basal mandibular margin expanded, and the PF is 3,4. In addition, the ant shares the apomorphies of its group including the large, centrally placed and diagonal propodeal spiracle.

Heterick (2009) - These ants are rather stocky and compact, and have an exceptionally large propodeal spiracle.

Distribution
Heterick et al. (2017) - The species, although not common, is widely distributed throughout Australia and has been recorded from all mainland states except the ACT and SA. In all likelihood, however, it also occurs in SA, at least.

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Nomenclature

 *  potteri. Melophorus potteri McAreavey, 1947: 25, fig. 1 (s.w.q.) AUSTRALIA.

Worker
Heterick et al. (2017) - (n = 6): CI 83–100; EI 19–25; EL 0.22–0.25; HL 1.05–1.29; HW 0.87–1.30; ML 1.26–1.59; MTL 0.64–0.89; PpH 0.18–0.20; PpL 0.59–0.64; SI 80–82; SL 0.72–1.04.

Minor. Head. Head rectangular; posterior margin of head planar to strongly convex; frons shining and smooth except for piliferous pits; 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 at about midpoint of head capsule; in profile, eye set anteriad of midline of head capsule; roughly ovoid, eye narrowed posteriad. In full-face view, frontal carinae straight, divergent posteriad; frontal lobes straight in front of antennal insertion. Anteromedial clypeal margin narrowly protrusive anteromedially, the protrusion with a square border; clypeal psammophore set at or just above anterior clypeal margin; palp formula 3,4. Mandibular teeth in minor worker consisting of five teeth on the masticatory margin, with additional small denticles on the basal margin; mandibles securiform; third mandibular tooth distinctly shorter than apical tooth, but equivalent in length to remaining teeth; masticatory margin of mandibles approximately vertical or weakly oblique. Mesosoma. Integument of pronotum, mesonotum and mesopleuron with weak to moderate sheen, shagreenate on pronotum and dorsum of mesonotum, otherwise microreticulate; anterior mesosoma in profile broadly convex; appearance of erect pronotal setae long (i.e., longest erect setae longer than length of eye) and unmodified; in profile, metanotal groove shallow, indicated mainly by an angle; propodeum matt or with a weak sheen and microreticulate; propodeum angulate, propodeal angle blunt; erect propodeal setae always absent; appressed propodeal setulae short, separated by more than own length and inconspicuous; propodeal spiracle situated nearer to midpoint of propodeum than to its declivitous face, and longer (length ≥ 0.50 × height of propodeum). Petiole. In profile, petiolar node squamiform; in fullface view, shape of petiolar node rectangular and variably concave medially; node shining and distinctly shagreenate-microreticulate. Gaster. Gaster shining, shagreenate (‘LP record’ appearance); pilosity of first gastral tergite consisting of well-spaced short, inconspicuous, appressed setae only, erect setae always absent. General characters. Colour of foreparts orange to dark tan, legs yellowish, gaster chocolate.

Major. Head. Head square; posterior margin of head planar or weakly concave; cuticle of frons shining and smooth except for piliferous pits; 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 straight, divergent posteriad; frontal lobes straight in front of antennal insertion. Anterior clypeal margin narrowly protrusive anteromedially, the protrusion with a square border; clypeal psammophore set at or just above anterior clypeal margin; palp formula 3,4. Mandibular teeth in major worker consisting of five teeth on the masticatory margin with additional small denticles on the basal margin; mandibles securiform; third mandibular tooth distinctly shorter than apical tooth, but equivalent in length to remaining teeth; masticatory margin of mandibles approximately aligned vertically or weakly oblique. Mesosoma. Integument of pronotum, mesonotum and mesopleuron with weak to moderate sheen, shagreenate on pronotum and dorsum of mesonotum, otherwise microreticulate; anterior mesosoma in profile broadly convex; erect pronotal setae absent; in profile, metanotal groove shallow, indicated mainly by an angle and metathoracic spiracles; propodeum shining and microreticulate; propodeum angulate, propodeal angle blunt; length ratio of propodeal dorsum to its declivity between 1:1 and 1:2; erect propodeal setae absent; appressed propodeal setae short, separated by more than own length and in conspicuous; propodeal spiracle situated nearer to midpoint of propodeum than to its declivitous face, and longer (length ≥ 0.50 × height of propodeum). Petiole. In profile, petiolar node squamiform; in full-face view, shape of petiolar node rectangular and variably concave medially; 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 only, erect setae always absent. General characters. Colour of foreparts orange to dark tan, legs yellowish, gaster brown.