Ponera scabra

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

Identification
Leong et al. (2019) - Worker: This species is characterized by a long antennal scape; a clypeus with an acute median tooth; a petiolar node in lateral view thick with straight anterior and posterior margins. Ponera scabra presents similarities with Ponera rishen, Ponera kohmoku, and Ponera takaminei. Ponera scabra can be distinguished from Ponera takaminei by its indistinct metanotal groove, while distinct in Ponera takaminei. Ponera scabra is distinct from Ponera kohmoku by its small eyes consisting of 5–7 facets, but about 20 facets in Ponera kohmoku. Ponera scabra is distinct from Ponera takaminei by the straight posterior margin of petiolar node in lateral view, while convex in Ponera takaminei.

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
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.

Taxonomic Notes
Leong et al. (2019): First of all, we found that a specimen (ANTC40459 collected from KiuShiu, Shiroyama, Japan) which was mistakenly pinned with the type label of Ponera scabra (see: Antweb.org 2017), deposited in. Regarding the type locality of P. scabra Wheeler, 1928, the species was described based on specimens collected from Mt. Maya, Hyogo Prefecture, Japan. Therefore, the specimen (ANTC40459) does not belong to type series. Secondly, this specimen was reported by Santschi in 1937, who identified it as a gynecoid worker of P. scabra (see: Santschi, 1937: 364). However, this specimen is not P. scabra and can be easily identified as Ponera kohmoku Terayama, 1996 by the combination of the following characters: large compound eye (ca. 30 facets), distinct metanotal groove and subcircular petiolar node in dorsal view; in contrast to P. scabra, which present small compound eye (ca. 5 facets), an indistinct metanotal groove and an arched petiolar node in dorsal view. In summary, we assume that the other specimens of P. kohmoku workers were also misidentified as P. scabra gynecoid by Santschi (1937). Thus, no valid record of gynecoid worker exist in the Ponera genus after the exclusion of Santschi’s record (1937).



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.

Leong et al. (2019) - (n=3): HL 0.74–78; HW 0.61–0.64; SL 0.53–0.54; A06L 0.04; A07L 0.05; A08L 0.07; A09L 0.08; A10L 0.10; PrW 0.48–0.52; WL 0.97–1.05; PeH 0.48–0.53; PeNL 0.27–0.29; PeW 0.42–0.47; ATL 0.57–0.60; ATW 0.64–0.68; CI 78–85, SI 84–92, PeI 87–92, LPeI 53–56, DPeI 151–166, ATI 88–93.

In full-face view, head rectangular and distinctly longer than broad (CI: 78–85), with slightly convex posterior margin, convex lateral margins and angularly rounded posterolateral corners. Eye small; composed of a total of 5 to 7 indistinct facets. Anterior clypeal margin with strong and acute medial tooth. Masticatory margin of mandible with a series of about 15 indistinct denticles, and three large teeth on the apical part. Antennal scape, when laid backward, almost reaching posterolateral corner; average ratio of the length of antennomeres 7/6:8/6:9/6:10/6 = 1.25: 1.69: 2.93: 3.40 (n=3).

Mesosoma. Mesosomal dorsum in lateral view slightly convex. Pronotum in dorsal view with broadly convex anterior margin, and well convex lateral margins. Metanotal groove indistinct. Lateral mesopleural suture distinctly incised. Propodeal dorsum in dorsal view slightly narrow with straight lateral margins. Propodeal corner in lateral view angular; propodeal dorsum and declivity forming approximatively a 120 degree angle.

Metasoma. Petiolar node in dorsal view thick and arched, with broadly convex anterior margin, and concave posterior margin. Petiolar node in lateral view trapezoidal and thick, with straight anterior and posterior margins; anterodorsal corner convex and higher than posterodrosal corner. Subpetiolar process large with large and circular fenestra, anteroventral corner blunt, almost straight ventral margin with a pair of well developed teeth. Third abdominal tergum distinctly broader than long (ATI: 88–93), with straight anterior margin, and slightly convex lateral margins.

Sculpture. Head densely punctate. Mandible sparsely punctate. Mesosoma densely punctate. Mesopleuron with densely striate and punctate. Metapleuron and propodeum striate. Propodeal declivity shining, but sparsely punctate. Lateral face of petiole densely punctate, posterior face smooth. The third and fourth abdominal segments densely punctate, other segments smooth and shining with few punctures.

Pubescence. Head, antennae, mesosoma, petiole, and gaster with evenly distributed short hairs. Mesopleuron, metapleuron, propodeum and lateral face of petiole with few short hairs. Dorsal and ventral faces of head, anterior margin of clypeus, sides of mandibles, dorsum of petiolar node, gastral sterna and posterior half of gastral terga with many long erect hairs. Subpetiolar process with a few long erect hairs.

Color. Body color black. Mandible, clypeus, antennae, legs, and apex of metasoma brown.

Queen
dealate Length 4 mm. Very similar to the worker. Head with even less convex sides and the petiole not so thick and with more concave posterior surface.

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.

Determination Clarifications
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.