Parvaponera Schmidt & Shattuck, 2014

Yamane, Seiki, Hosoishi, Shingo & Ito, Fuminori, 2024, Taxonomic study on the queens of the Japanese ponerine genera, with a redescription of Ectomomyrmex horni restituted as a valid species (Hymenoptera: Formicidae), Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 64 (2), pp. 249-267 : 260

Parvaponera Schmidt & Shattuck, 2014

( Figs 3D , 5D , 7D )

Recognition. Body yellowish; medium-sized ants measuring 5.0– 5.5 mm in total body length; eye almost touching anterior margin of cranium; mandible without basal pit; petiole node-like, in profile view thick, lacking anterior fenestra; mid- and hindtibiae with both simple spur and longer pectinate spur in apicoventral part.

Description of queen. Medium-sized ponerine, measuring 5.0– 5.5 mm in total body length and 0.96–1.00 mm in head width. In full-face view, head (excluding eyes) almost as long as broad, slightly narrowed posteriad, with broadly emarginate posterior margin, straight lateral margin and rounded posterolateral corner. Malar space almost absent. Clypeus only shallowly convex anteriorly. Mandible elongate-triangular, without basal pit; masticatory margin with 7–8 strong teeth of varying size. Eye round with ca. 20 ommatidia along longest axis, with many rather long erect hairs. Three ocelli arranged in right triangle. With mesosoma in dorsal view promesonotum much narrower than head; mesoscutum flat with weak parapsidal line and parascutal carina; scutoscutellar sulcus linear for most of its length; mesoscutellum and metanotum smooth with superficial punctures. Opening of propodeal spiracle linear. Petiole node-like, in profile view thick; tergite separated from sternite with deep sulcus flanked with sharply defined carinae; subpetiolar process with anterior fenestra, but lacking posterior paired spines. Prora small, scale-like, margined with dark rim. Gastral constriction rather strong; pretergite of gastral segment II smooth with very superficial sculpture and strongly shiny; presternite densely with minute punctures and matte; cinctus not clearly defined, represented by impressed line. Mid- and hindtibiae with simple spur and longer pectinate spur in apicoventral part. Hindwing without jugal lobe.

Caste differences. The worker is much smaller (TL ca. 3.5 mm; HW 0.86 mm) than the queen. The eye is vestigial with a few ill-defined ommatidia. The median line on the cranium is less conspicuous than in the queen, in which it is well defined, starting at the anterior ocellus and reaching the posterior margin of the frontal lobes.

Remarks. The single Japanese species P. darwinii is very similar to Cryptopone species in size, general habitus and sometimes coloration, but it is easily distinguished from the latter by the following combination of characteristics: 1) mandible without basal pit, 2) midtibia without strong bristles on outer surface, and 3) subpetiolar process with anterior fenestra.Among the Japanese genera the pretergite of the gastral segment II differs in sculpturation type from the presternite solely in this genus.

Figures

Fig. 3. Habitus (queen) in profile view. A – Cryptopone sauteri (Wheeler, 1906) (Aman-dake, Hirado-jima, Nagasaki-ken, Kyushu, 7.ix.1982, K. Ogata & S. Eto leg.); B – Diacamma cf. indicum Santschi, 1920 (gamergate) (Ishimine, Naha-shi, Okinawa-jima, Okinawa Is., Okinawa-ken, 24.iv.1979, K. Ogata leg.); C – Ecto- momyrmex horni (Forel, 1913) (Campus of Kagoshima Univ., Kago- shima-shi, Kagoshima-ken, Kyushu, 21.ix.1992, Sk. Yamane leg.); D – Parvaponera darwinii (Forel, 1893) (Yui-dake, Amami-ôshima, Amami Is., Kagoshima-ken, 26.vii.2019, Sk. Yamane leg.); E – Ponera kohmoku Terayama, 1996 (Shiroyama, Kagoshima-shi, Kagoshima-ken, Kyushu, 24.x.1978, K. Ogata leg.).

Fig. 5. Habitus (queen) in dorsal view. A – Cryptopone sauteri (Wheeler, 1906); B – Diacamma cf.indicum Santschi, 1920 (gamerga- te); C – Ectomomyrmex horni (Forel, 1913); D – Parvaponera darwinii (Forel, 1893); E – Ponera kohmoku Terayama, 1996. (Collection data same as in Fig. 3).

Fig. 7. Head (queen) in full-face view. A – Cryptopone sauteri (Wheeler,1906);B–Diacammacf.indicumSantschi,1920(gamergate); C – Ectomomyrmex horni (Forel, 1913); D – Parvaponera darwinii (Forel, 1893); E – Ponera kohmoku Terayama, 1996. (Collection data same as in Fig. 3).