Gnamptogenys dentihumera Chen, Lattke & Zhou, 2017

Chen, Zhilin, Lattke, John E., Shi, Fuming & Zhou, Shanyi, 2017, Three new species of the genus Gnamptogenys (Hymenoptera, Formicidae) from southern China with a key to the known Chinese species, Journal of Hymenoptera Research 54, pp. 93-112 : 95-96

Gnamptogenys dentihumera Chen, Lattke & Zhou sp. n. Figs 1 , 10 ; Map 1

Type material.

Holotype. Worker. CHINA: Guangxi, Huanjiang County, Jiuwan Mountain, 25°11'00"N, 108°36'57"E, 925m, 8.VIII.2015, leg. Zhilin Chen, No. G150067. Paratypes. 12 workers and 1 queen, data the same as holotype. [1 worker holotype, 8 workers pratypes and 1 queen paratype specimens are deposited in the Insect Collection, Guangxi Normal University, Guilin, China (GXNU); 2 workers paratypes will be deposited in the Insect Collection, Southwest Forestry University, Kunming, Yunnan Province, China (SWFU); 2 workers paratypes will be deposited in the Institute of Zoology, Chinese Academy of Sciences, Beijing, China (IZCAS)].

Holotype worker

(Figs 1-4 ). TL 4.61, HL 1.45, HW 1.22, CI 84, SL 1.05, SI 86, ED 0.14, PW 0.96, MSL 1.71, PL 0.41, PH 0.95, DPW 0.58, LPI 231, DPI 141. In full-face view head rectangular, longer than broad; posterior margin almost straight, posterior corner bluntly angular, lateral margin weakly convex. Mandible triangular, masticatory margin crenulate. Anterior margin of clypeus with convex to bluntly pointed median lobe. Antennal scape just slightly surpassing posterior corner of head, flagellar segments longer than broad. Eye small, with 10 ommatidia along maximum diameter, situated on midpoint of cephalic lateral margin.

In lateral view occipital lamella of head forming a blunt triangular denticle. Dorsum of mesosoma strongly convex, promesonotal suture slightly impressed. Propodeum with short triangular denticle; propodeal declivity weakly concave close to tooth then relatively straight. Petiole roughly trapezoidal, about 2.1 times higher than long, dorsal and anterior margins weakly convex, posterior margin straight, subpetiolar process broadly triangular. Sting extruding.

In dorsal view anterolateral margin of pronotum with strong constriction, forming pointed denticle on humeral area. Metanotal groove ambiguously evident, evidenced by a change in sculpturing. Petiolar anterior corner rounded, lateral margin weakly convex in dorsal view.

Mandibular dorsum and clypeus with longitudinal fine striae; cephalic dorsum mostly longitudinally rugulose-foveolate; side of pronotum, propodeum, petiole and third abdominal tergite and sternite rugulose-foveolate; posteromediand pronotum and mesonotum with longitudinal striae; propleuron irregularly rugulose; meso- and metapleuron longitudinally striate; fourth abdominal tergite finely irregularly rugulose, sternite rugulae denser than on tergite. Propodeal declivity transversely striate. Head, mesosoma, petiole, and gaster with abundant suberect hairs and sparse decumbent pubescence. Scape and tibiae with sparse sub-decumbent hairs and dense decumbent pubescence. Body color black; mandible, antenna and leg reddish-brown.

Paratype workers

(n = 12). TL 4.56-4.65, HL 1.43-1.45, HW 1.20-1.23, CI 83-85, SL 1.03-1.05, SI 84-87, ED 0.13-0.15, PW 0.94-0.95, MSL 1.70-1.72, PL 0.40-0.43, PH 0.93-0.96, DPW 0.56-0.58, LPI 230-233, DPI 137-143. General appearance as in holotype, with some specimens reddish brown to yellowish brown in color. We believe they are callow workers.

Paratype queen

(Figs 5-10 ). TL 6.42, HL 1.55, HW 1.21, CI 78, SL 1.11, SI 91, ED 0.25, PW 1.21, MSL 2.31, PL 0.37, PH 1.12, DPW 0.71, LPI 302, DPI 191. In full-face view head rectangular, longer than broad, posterior margin weakly concave, posterior corner bluntly angular, lateral margin almost parallel. Three ocelli on vertex (two lateral and one median) bordered by dark patches. Mandible triangular, masticatory margin crenulate. Anterior margin of clypeus with convex to bluntly pointed median lobe. Antennal scape just slightly surpassing posterior corner of head. Eye situated on midpoint of lateral cephalic margin.

In lateral view occipital lamella of head forming blunt point. Dorsum of mesosoma convex. Promesonotal suture obvious. Petiole relatively thin, anterior margin convex, posterior margin straight, dorsal and anterior margin with no obvious boundary, subpetiolar process broadly triangular. Sting extruding.

In dorsal view anterior margin of pronotum rounded; metanotal groove distinct. Metanotum oval, very narrow, bordered by mesoscutellum and propodeum. Petiole anterior weakly rounded.

Forewing and hindwing of queen shown in Figs 6-7 .

Mandibular dorsum, anterolateral cephalic surface and middle part of clypeus with fine longitudinal striae. Head, pronotum, propodeum and petiole coarsely rugulose; middle part of mesonotum longitudinally striate; propleuron irregularly rugulose; mesopleuron and metapleuron longitudinally rugulose; in lateral view, third abdominal tergite with semicircular rugulae; fourth abdominal tergite with fine short rugulae; propodeal declivity transversely striate. Head, mesosoma, petiole, and gaster with abundant sub-erect hairs and sparse decumbent pubescence; scape and tibiae with sparse sub-decumbent hairs and dense decumbent pubescence. Whole body reddish-brown.

Male.

Unknown.

Habitat.

This species was found nesting in deadwood of a branch on the ground in a subtropical evergreen broad-leaved forest, at the altitude of 925 m. All ants came from the same nest.

Etymology.

This species is named from the Latin words “dent” (denticle) and “humer” (humeral), referring to the pronotum humeral area forming a pair of pointed denticles.

Differential diagnosis.

The workers of Gnamptogenys dentihumera are similar to workers of Gnamptogenys panda , but Gnamptogenys dentihumera can be distinguished from the latter by propodeum with short triangular denticle and triangular subpetiolar process. The workers of Gnamptogenys dentihumera also resemble Gnamptogenys sinensis , but differ from the latter by the occipital lamella of head shaped as a blunt triangular denticle, and the pronotal humeral denticle of the workers of Gnamptogenys dentihumera is short, pointing laterally, unsurpassing the anterior margin of pronotum.

Figures

Map 1. Distribution of ten known species of the genus Gnamptogenys in China. The data came from collection specimens and literatures.

Figures 1 - 4. Gnamptogenys dentihumera holotype worker (No. G 150067). 1 head in full-face view 2 petiole in lateral view 3 body in dorsal view 4 body in lateral view.

Figures 5 - 10. Gnamptogenys dentihumera paratype queen. 5 head in full-face view 6 forewing in dorsal view 7 hindwing in dorsal view 8 gaster in dorsal view 9 body in dorsal view 10 body in lateral view.