Ponera scabra

Collected but a few times, little is known about Ponera scabra.

Identification
Taylor (1967) - A Japanese species closely related to, and possibly cognate with, Ponera chapmani. Distinguished in general from other Ponera species by the combination of moderately large size (head width 0.61-0.64 mm in worker, 0.71-0.74 mm in queen), heavy sculpturing, and long scapes, which almost exactly reach the median occipital border. Readily differentiated from the only other known Japanese species, Ponera japonica, by its larger size (head width 0.42-0.50 in japonica) and heavier sculpturation. P. scabra may be differentiated from the related chapmani by characters stated below in the worker description.

Distribution based on Regional Taxon Lists
Indo-Australian Region: New Guinea. Palaearctic Region: China, Democratic Peoples Republic of Korea, Japan, Republic of Korea.

Nomenclature

 *  scabra. Ponera scabra Wheeler, W.M. 1928d: 99 (w.q.) JAPAN. Santschi, 1937h: 364 (gynecoid w.); Santschi, 1941: 273 (q.); Ogata, 1987: 121 (m.); Imai & Kubota, 1972: 194 (k.). Senior synonym of yakushimensis: Yoshimura, Hosoishi, et al. 2009: 195. See also: Wilson, 1957b: 381; Taylor, 1967a: 49.
 * yakushimensis. Ponera yakushimensis Tanaka, 1974b: 32, fig. 1 (w.q.) JAPAN. Junior synonym of scabra: Yoshimura, Hosoishi, et al. 2009: 195.

Worker
Taylor (1967):

1. The 3 large apical mandibular teeth occupy about 1/3 of the masticatory border, and are followed by a series of 10-12 minute denticles.

2. Median clypeal denticle much less pronounced, at least in smaller specimens (see below).

3. Scapes relatively short; when laid back along head they almost exactly reach the median occipital border.

4. Head narrower (cephalic index 78-83 opposed to 83-85 in chapmani).

5. Mesometanotal suture much less distinctly incised, although indicated by a break insculpturation.

6. Posterior border of node, viewed from above, distinctly concave. Node relatively wide (petiolar node index 84-89 opposed to 79-80 in chapmani).

7. Sculpturation of mesosoma and node much more pronounced; striae of propodeal declivity and posterior face of node lacking (see Wilson's description).

The posterior face of node with fine transverse superficial "scaly" sculpturation, like that on propodeal declivity of Ponera alpha, but more distinctly developed. This sculpturation, which probably represents a vestigial striate-rugosity, is more distinct on the lower 1 /2 of face than above.

Additional description. The following notes are based on 7 syntype workers and 2 dealated syntype queens from the MCZ and AMNH collections. An additional unstudied syntype worker is in the USNM collection (M. R. Smith, in litt). Wheeler presumably returned some of his types to Silvestri and it is not known whether he designated a holotype. Accordingly, no lectotype selection has been made here.

Syntypes (figs. 31, 32). In addition to the features indicated in the diagnosis above the following details should be noted: HL 0.77-0.80 mm; HW 0.61-0.64 mm; SL 0.56-0.59 mm; CI 78-80; SI 90-93; PW 0.46-0.50 mm; PNL 0.26-0.28 mm; PH 0.49-0.53 mm; DPW 0.39-0.43 mm; PNI 84-88.

Eyes about 0.03 mm in diameter, with 3-5 indistinct facets. Median clypeal tooth at best vestigial, represented by a low flat tumosity ; a little more distinct in larger specimens. Antennal club as described for chapmani. General form of propodeum as in chapmani; petiolar node somewhat bulkier (cf. figs. 30, 32).

Additional workers. 2 workers from Hikosan, Kyushu (K. Yasumatsu) have the following dimensions : HL 0.78 mm, 0.84 mm; HW 0.64 mm, 0.70 mm; SL 0.57 mm, 0.61 mm; CI 82, 83; SI 89, 87; PW 0.49 mm, 0.55 mm; PNL 0.25 mm, 0.30 mm; PH 0.51 mm, 0.55 Mm; DPW 0.44 mm, 0.47 mm; PNI 89, 85. These specimens agree well with the syntypes but have relatively high CI and low SI values. The larger specimen is probably slightly gynecoid; its eyes are about 0.05 mm long with 7 rather distinct facets, and the median clypeal denticle is well developed, as in queen. The palpal formula (smaller specimen dissected): Maxillary 2 : Labial 2.

Queen
Taylor (1967) - Differentiated from queen of Ponera chapmani by larger size and the same mandibular, scape, nodal and sculptural characters which distinguish the worker. Compound eye distinctly smaller, its maximum diameter 0.25 to 0.26 X head width, opposed to 0.29 to 0.30 X HW in chapmani. Wing venation unknown (unfortunately; considering the peculiar venation of chapmani).

Syntypes (N = 2): HL 0.87 mm; HW 0.71 mm, 0.74 mm; SL 0.64 mm, 0.65 mm; CI 82, 85; SI 90, 88; PW 0.60 mm, 0.66 mm; single measurements (1st specimen) for PNL 0.30 mm and PH 0.60 mm; DPW 0.51 mm, 0.55 mm; PNI 85, 83; maximum diameter of compound eye 0.18 mm; 0.19 mm; ocular index 25, 26.

Differing from the workers in the usual characters, and from other Ponera queens by the characters of the diagnosis above. The palpal formula has not been checked.

Mis-identification Notes
Taylor (1967) - The records of Ponera scabra published in the important ecological studies of Hokkaido ants by Hayashida (1957, 1960) were in fact based on incorrectly determined specimens of Ponera japonica, which were generously made available for this study by Dr Hayashida. For further information see japonica.