Heteroponera relicta (Wheeler)

Taylor, Robert W., 2015, Australasian ants of the subfamily Heteroponerinae (Hymenoptera: Formicidae): (2) the species-group of Heteroponera relicta (Wheeler), with descriptions of nine new species and observations on morphology, biogeography and phylogeny of the genus, Zootaxa 3947 (2), pp. 151-180 : 158-161

1. Heteroponera relicta (Wheeler)

( Figs 2–5, 6–9)

Paranomopone relicta Wheeler, 1915: 118 , pl. 8; Worker, Gyne; Type locality: AUSTRALIA: QUEENSLAND: Kuranda (16°49'S, 145°38'E). Holotype examined (Museum of Comparative Zoology, Cambridge, Massachusetts, USA). Heteroponera relicta W.L. Brown, 1958: 196 .

Distribution, material examined. Abundantly known from many localities centered on the Atherton Tableland of NE Qld, north to near Mossman and south almost to the latitude of Townsville (Grid cells -16/145, -17/145 and - 18/146), as follows: EA4 (Mt Carbine Tableland): Mossman Bluff Track ; Mossman Gorge ; Mt Demi; Mt Lewis; 2.5 km N of Mt Lewis; 2 km SE of Mt Spurgeon; The Bluff (11 km W Mossman ); Pauls Luck; Platypus Creek. EA6 (Black Mountain): Black Mountain (17 km ESE Julatten); Black Mountain Rd (via Kuranda ); Clacherty Rd (via Julatten); Kuranda ; Lyons Lookout (near Mossman ). EA7 (Lamb Range): Davies Creek Rd; Emerald Creek; Lamb Range. EA8 (Walsh/ Hugh Nelson Range): Bartle Fire Track (17 km W Millaa Millaa); Herberton Range; Hugh Nelson Range (2.5 km S of Crater NP); Mt Fisher; 21 km S of Atherton. EA9 (Atherton Tableland): 3.2 km E of Lake Barrine; Lake Barrine NP; Lake Eacham NP; Malanda Falls; 12 km SE of Millaa; 7 km SW of Millaa; Danbulla Forest; Gadgarra . EA10 ( Bellenden Ker ): Bellenden Ker Range (E slope, sited near various specified cable-car towers); Boonjie (13 km ESE Malanda); Topaz area. EA11 (Malbon Thompson Range): Mt Gorton (near Yarrabah); Bell Peak North (near Gordonvale). EA12 (Walter Hill Range): 25 km SE of Millaa; Boulder Creek (via Tully); Downie Creek; Koombooloomba; Tully River Crossing; Tully Falls NP; Crawfords Lookout; W of McNamee Creek. Laceys Creek; McNamee Creek (15 km SW of Innisfail); Mt Father Clancy (9 km S of Milla Milla); Palmerston NP. EA13 (Kirrama/ Cardwell Range): MacAlister Range (W slope). EA16 (Paluma/ Bluewater Ranges): Mt Spec.

All samples with ecological data are labelled “Rainforest” or “RF”. Relevant collectors include: E.H. Bourne, W.L. Brown, A.N. Burns, H. Janetzki, DWC, JDF, BBL, GBM, RWT, GIT, DKY. Heteroponera relicta has been identified here from QMBA berlesates numbered: 238, 249, 298, 300, 312, 365, 408, 413, 466, 549, 598, 609, 611, 612 and 618.

Elevational distribution. Specified elevations range from 60m ( Mossman Gorge ) to 1000–1200m (Mt Spurgeon, Lamb Range and Herberton Range).

Worker diagnosis. General features, conformation, color and major sculpturation as in Figs 2–5 and relevant key couplets above. Body color frequently more nearly black than illustrated. Described in adequate detail by Wheeler (1915). Readily identified by key characters cited above and the accompanying illustrations. Humeral angles and pronotal epaulets well-developed. Scrobes generally smooth and shining, usually with very light rippling of the surfaces of the medial scrobal areas. Propodeal declivity smooth and shining, sometimes with slight traces of irregular longitudinal sculpturing. Lateral margins of declivity simple, essentially the unelaborated edges of the lateral and dorsal propodeal sculpturation. A small smooth, shining area medially on the posterior surface of the node. Dimensions: (smallest available specimen (Black Mountain Rd, Kuranda ), largest available specimen (Downey Creek)): TL (ca): 5.1, 6.0; HW: 1.19, 1.47; HL: 1.14, 1.34; CI: 104, 109; EL: 0. 19, 0.24; SL: 0.70, 0.82; SI: 58, 56; PW: 0.83, 1.07; WL: 1.42, 1.72; petH: –, 0.96; petW: 0.43, 0.62; GW 0.98, 1.21.

Gyne: General features and major sculpturation as in Figs 6–9. Head size, proportions, structure and sculpturation close to the worker range. One specimen (illustrated here) has an apparently unreduced median ocellus (as did Wheeler’s (1915) Kuranda gyne). Mesosoma remarkably worker-like (considering that structural reduction from alate ancestry must have occurred separately from that in the evolution of the worker caste), with vestigial traces of ancestral alate-related structure as illustrated; sculpturation less strongly expressed than in worker; PW and WL generally within the worker range, WL ranging slightly higher. Dimensions: Four specimens from colonies collected at Mossman Gorge, Malanda Falls, Lake Eacham , and Palmerston National Park have the following dimensions: TL (ca): 5.7, 6.6, 6.5, 6.5; HW: 1.28, 1.38, 1.38, 1.40; HL: 1.23, 1.31, 1.33, 1.30; CI: 104, 105, 103, 107; EL: 0.23, 0.25, 0.25, 0.26; SL: 0.72, 0.76, 0.75, 0.74; SI: 56, 55, 54, 53; PW: 0.97, 0.97, 1.02, 1.06; WL: 1.59, 1.75, 1.73, 1.79; petH: -, 1.15, 1.00, 1.11; petW: 0.70, 0.81, 0.75, 0.72; GW (across gastral segment III): 1.58, 1.68, 1.69, 1.66. Two specimens from Platypus Creek have HW 1.36mm.

Related taxa. H. rhodopygea and H. relicta are closely similar and apparently phylogenetically cognate. They are not known to occur sympatrically, though both are recorded from (well separated) localities in EA4 (Carbine Tableland) and otherwise have extensive, well-defined allopatric distributional ranges. Heteroponera relicta workers are larger on average. HW of 40 randomly selected. rhodopygea workers ranged from 1.18 to 1.39mm (mean 1.32mm, distribution roughly bimodal with modes at 1.28mm and 1.34mm. The main range was 1.26mm to 1.39mm, with a divergent small individual at I.18mm (see full measurements below). HW of 40 randomly selected H. relicta workers ranged from 1.19mm to 1.47mm (mean 1.36mm) with frequency distribution essentially flat. The main range was 1.32–1.47mm, with 4 small (?nanitic) individuals in the range 1.20–1.28mm. Thus 42% of measured H. relicta workers were larger than any measured rhodopygea worker. These comparisons could be affected by generational differences in stature among workers in growing colonies, and by geographical variation in maximum worker size.

Heteroponera darlingtonorum and H. wilsoni are both similar to H. relicta , but with distinctive sculptural differences, and somewhat simplified morphological structural detail, especially in H. wilsoni . In both species the propodeum is dorsally slightly inflated and less strongly sloping posterodorsally in profile view than in H. relicta .

In-group sympatric associations. Sympatric variously with H. pendergrasti and H. wilsoni (see those species entries for details), with H. ecarinata at Crawfords Lookout, and with H. darlingtonorum in the Paluma area.

Remarks. H. relicta was included in Feitosa’s (2011) phylogenetic analysis as a sister species to H. rhodopygea (his “ Heteroponera sp A”).