Royidris notorthotenes (Heterick) Heterick, 2014

Bolton, Barry & Fisher, Brian, 2014, The Madagascan endemic myrmicine ants related to Eutetramorium (Hymenoptera: Formicidae): taxonomy of the genera Eutetramorium Emery, Malagidris nom. n., Myrmisaraka gen. n., Royidris gen. n., and Vitsika gen. n .., Zootaxa 3791 (1), pp. 1-99 : 57-59

Royidris notorthotenes (Heterick) comb. n.

(Figs 60-62, Map 142)

Monomorium notorthotenes Heterick , 2006: 91, figs 14, 85-89. Holotype and paratype workers, MADAGASCAR: Prov. Toliara, Res Cap Sainte Marie, 14.9 km. 261° W Marovato, 25°36'S, 45°09'E, 160 m., 13-19.ii.2002, BLF 5740, under stone, spiney forest thicket, (holotype CASENT0002257) (Fisher, et al.); other paratypes, series BLF 5741 (workers, queens and males), otherwise with the same collection data as the holotype (CASC, BMNH, ANIC, MCZC) [CASC examined]. Comb. n.

WORKER. TL 3.6-4.3, HL 0.80-0.98, HW 0.65-0.81, CI 78-84, SL 0.86-1.00, SI 115-132, PW 0.43-0.51, WL 1.02-1.34 (20 measured).

Antennal club 4-segmented, funicular segments 8 and 9 of equal length. Mandible longitudinally costulate. Scapes relatively long (SI 115-132); when laid straight back in full-face view the apex of the scape very obviously exceeds the posterior margin of the head. With head in full-face view the eyes at the midlength of the side of the head capsule. EL 0.20-0.24 (EL/HW 0.29-0.32). Dorsum of head from level of eyes to posterior margin almost smooth, with only faint, superficial remnants of reticulate or feeble, disorganised punctulate sculpture. Promesonotum in profile convex and swollen, the mesonotum with a long posterior slope that descends to the very feebly indicated metanotal groove. In absolute profile the propodeal dorsum is horizontal, flat to very nearly flat, posteriorly with a bluntly rounded angle. The whole propodeal dorsum is strongly depressed with respect to the highest point of the promesonotum, which is on a considerably higher level. Pronotum with 3-5 pairs of setae; mesonotum with 2-3 pairs; dorsum of propodeum lacks standing setae. Pronotal dorsum usually with weak, superficial reticulate-punctulate sculpture, at least near the midline; sometimes the sculpture reduced to microreticulation, but the surface never entirely smooth and polished. Propodeal dorsum very finely and densely reticulate-punctulate, the sculpture usually more distinct than on the pronotal dorsum. Side of pronotum superficially microreticulate to weakly reticulate-punctulate; mesopleuron and metapleuron finely and densely reticulate-punctate. Metafemur appears strongly incrassate, with MfL 0.88-1.10 (MfL/HW 1.28-1.39, MfL/MfH 3.62-4.15). Petiole with one pair of setae, on its posterior face near the base; postpetiole with setae on its dorsal and posterior faces; first gastral tergite with numerous suberect setae that are shorter than the maximum vertical diameter of the eye. Postpetiole relatively narrow in dorsal view, maximum width 0.20-0.24 (ca 0.30 x HW). Dorsum of postpetiole with very weak reticulate-punctulate or superficial granulate sculpture, sometimes vestigial. First gastral tergite unsculptured, or at most with traces of superficial microreticulate patterning. Entirety of head, mesosoma, petiole, postpetiole, legs and gaster yellow.

QUEEN (gyne). Alate when virgin. Much larger than worker. TL 6.4-7.1, HL 1.24-1.26, HW 1.16-1.22, CI 94-97, SL 1.02-1.04, SI 84-89, PW 0.88-1.02, WL 2.06-2.14, EL 0.36-0.38 (EL/HW 0.30-0.32), MfL 1.20-1.26 (MfL/HW 1.00-1.07, MfL/MfH 4.20-4.40), maximum dorsal length of mesoscutum 1.00-1.05, maximum width of mesoscutum 0.95-1.07, maximum dorsal width of postpetiole 0.42-0.48 (0.38-0.39 x HW) (5 measured). Head somewhat more strongly sculptured than in worker, and with weak longitudinal costulae in front of the ocelli. Mesoscutum unsculptured except for minute, widely scattered pits; mesoscutellum unsculptured, smooth. Propodeal dorsum with fine transverse costulae, between which are traces of superficial punctulation. Petiole, and postpetiole finely reticulate-punctate. First gastral tergite unsculptured, or with superficial vestiges of faint microreticular patterning. Side of mesosoma mostly smooth, with scattered patches of minute weak punctulae or microreticulation. Propodeum rounded to very bluntly and obtusely angular posteriorly, without a well-defined tooth or dentiform angle between dorsum and declivity. All dorsal surfaces except propodeum with numerous fine setae; propodeum entirely lacks setae. Colour generally as in worker, but apex of each gastral tergite with a darker transverse band.

MALE. Smaller than worker, much smaller than queen. HL 0.52-0.54, HW 0.51-0.53, WL 0.98-1.02 (2 measured). Head dorsoventrally flattened, the clypeus not bulging in profile. With head in profile the length of the cephalic dorsum between the posterior ocellus and the occipital carina is much less than the length of the ocellus. See also under diagnosis of genus.

R. notorthotenes is part of a small complex, which also includes diminuta and etiolata , together characterised by a 4-segmented antennal club in which funicular segments 8 and 9 are of equal length, uniform yellow colour, and cephalic sculpture that is weak to vestigial. They all have relatively long scapes (SI 115-158), a head that averages relatively narrow (CI 75-84), and long metafemora (MfL/HW 1.25-1.50). Morphologically, these three species are strikingly similar, but their workers can be separated by their relative dimensions, as discussed under diminuta and etiolata .

All samples of notorthotenes are from spiny forest. They have been discovered nesting under stones and foraging on the ground, and have also been retrieved from pitfall traps.

Material examined. Madgascar: Prov. Toliara, Res. Cap Sainte Marie, W Marovato (Fisher et al.); Prov. Toliara, P.N. Tsimanampetsotsa, Bemanateza (Fisher et al.); Prov. Toliara, P.N. Tsimanampetsotsa, Mitoho, ENE Efoetse (Fisher et al.); Prov. Toliara, SSE Lavanono (Fisher et al.); Prov. Toliara, Foret Tsinjoriaky, E Tsifota (Fisher et al.); Prov. Toliara, Mahafaly Plateau, ENE Itampolo (Fisher et al.).