Gnamptogenys quadrutinodules 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 : 99-103

Gnamptogenys quadrutinodules Chen, Lattke & Zhou sp. n. Figs 15-18 , 19-23 , 24-28 ; Map 1

Type material.

Holotype worker. CHINA: Jianxi, Guangfeng County, Tongbo Mountain, 28°05'35"N, 118°14'20"E, 1026m, 2.IX.2012, leg. Chunwen Lu, No. G120081. Paratypes. 2 workers, 1 male and 1 queen, data the same as holotype. [The holotype and paratypes are deposited in the Insect Collection, Guangxi Normal University, Guilin, China (GXNU)].

Holotype worker

(Figs 15-18 ). TL 4.22, HL 1.05, HW 0.86, CI 82, SL 0.73, SI 84, ED 0.08, PW 0.71, MSL 1.31, PL 0.25, PH 0.61, DPW 0.50, LPI 244, DPI 200. In full-face view head rectangular, distinctly longer than broad, posterior margin almost straight, posterior corner nearly right-angular, lateral margin slightly convex. Mandible triangular, masticatory margin crenulate. Anterior margin of clypeus with convex to bluntly pointed median lobe. Antennal scape just reaching posterior corner of head, flagellar segments 3-7 broader than long. Eye very small, with 5 ommatidia along maximum diameter, situated on the midpoint of lateral cephalic margin.

In lateral view occipital lamella of head narrow and inconspicuous; dorsum of mesosoma moderately convex; promesonotal suture obvious. Propodeum with short triangular denticle; propodeal declivity longitudinally weakly concave, laterally with margin. Petiole roughly sub-quadrate, about 1.7 times higher than long, anterior corner slightly rounded, posterior corner bluntly angulate, dorsal and anterior margin weakly convex, posterior margin straight. Subpetiolar process subquadrate. Sting extruding.

In dorsal view humeral angle rounded; promesonotal suture visible; metanotal groove absent. In dorsal view petiolar node with approximate semicircular anterolateral margin, anterior margin convex and separated from lateral margin by weak blunt angle, lateral margin weakly convergent posteriorly, each margin weakly convex; posterior margin weakly concave; node about 1.5 times as long as broad; anterior petiolar corner rounded, posterior corner blunt.

Mandibular dorsum and clypeus with longitudinal fine striate; space between frontal carinae with four longitudinal striae, rest of head partly rugulose-foveolate; pronotum, propodeum, petiole and anterior two-thirds of third abdominal tergite rugulose-foveolate; middle part of mesonotum with four longitudinal striae; propleuron, mesopleuron and metapleuron irregularly rugulose; dorsum of fourth abdominal tergite smooth, sides with fine short rugulae; propodeal declivity reticulate-rugose. Head, mesosoma, petiole, and gaster with abundant sub-erect hairs. Scape and tibiae with sparse sub-decumbent hairs. Head, mesosoma and petiole black-brown; mandible, antenna, gaster and legs reddish-brown.

Paratype workers

(n = 2). TL 4.18-4.23, HL 1.02-1.06, HW 0.84-0.87, CI 80-83, SL 0.71-0.74, SI 82-85, ED 0.08-0.09, PW 0.70-0.73, MSL 1.30-1032, PL 0.23-0.26, PH 0.61-0.63, DPW 0.48-0.51, LPI 243-245, DPI 198-202. As the holotype.

Paratype queen

(Figs 19-23 ). TL 5.52, HL 1.21, HW 0.96, CI 79, SL 0.81, SI 84, ED 0.21, PW 0.96, MSL 1.61, PL 0.25, PH 0.72, DPW 0.42, LPI 288, DPI 168. In full-face view head rectangular, longer than broad, middle of posterior margin weakly concave, posterior corner bluntly angular, lateral margin weakly convex. Three ocelli on vertex (two lateral and one median). Mandible triangular, masticatory margin crenulate. Anterior margin of clypeus with convex to bluntly pointed median lobe. Antennal scape almost reaching posterior corner of head. Eye large, more than 20 ommatidia present along maximum diameter, situated on midpoint of lateral cephalic margin.

In lateral view occipital lamella of head narrow and inconspicuous. Dorsum of mesosoma moderately convex. Promesonotal suture obvious; propodeum with short triangular denticle; propodeal declivity weakly concave. In lateral view petiole trapezoid, anterior corner slight rounded, posterior corner angulate, dorsal margin weakly convex, anterior and posterior margins straight. Subpetiolar process sub-quadrate. Sting extruding.

In dorsal view pronotal anterolateral corner rounded. Metanotal groove distinct. Petiole relatively thick, anterior margin slightly convex.

Forewing and hindwing of queen as shown in Figs 20-21 .

Mandible dorsum, gena and clypeus with longitudinal fine striae; head, pronotum, propodeum, propleuron and petiole coarsely rugulose; mesonotum with longitudinal striae; mesopleuron and metapleuron longitudinally rugulose; third abdominal tergite rugulose-punctate; fourth abdominal tergite with scattered piligerous punctures; de clivity transversely striate. Head, mesosoma, petiolar node and gaster with abundant sub-erect hairs; scape and tibiae with sparse sub-decumbent hairs and dense decumbent pubescence. Whole body reddish-brown.

Paratype male.

(Figs 24-28 ). TL 4.73, HL 0.85, HW 0.76, CI 89, SL 0.21, SI 27, ED 0.36, PW 0.82, MSL 1.61, PL 0.45, PH 0.33, DPW 0.36, LPI 73, DPI 80. In full-face view head oval. Eyes large, maximum diameter about 0.35mm, occupying about half of lateral cephalic margin, situated on midpoint of lateral cephalic margin. Three ocelli on vertex (two lateral and one median). Frontal carina short. Mandible triangular, masticatory margin with many small teeth; anterior margin of clypeus broadly rounded. Antennal scape short, just reaching anterior margin of median ocellus.

In lateral view posterior carinae of head conspicuous. Mesoscutellum higher than mesoscutum; mesopleural oblique furrow distinctly wide. Propodeal lobe bluntly triangular; dorsum of propodeum as long as declivity, posterodorsal corner inconspicuous. Petiole elongated oval; subpetiolar process shaped as rounded translucent lamella.

In dorsal view mesosoma spindle-shaped. Parapsidal sulcus and notaulus present, notaulus conspicuous. Metanotum small, not reaching to the lateral margins. Petiole trapezoidal, anterior margin slightly convex, posterior margin straight, anterior corners rounded.

Forewing and hindwing of male as shown in Figs 25-26 .

Mandibular dorsum and declivity of propodeum longitudinally finely striate; head, metapleuron and petiole irregularly finely rugulose; pronotum, propleuron, mesopleuron smooth; anterior margin of first gastral tergite with short striae; declivity longitudinally striate. Head and mesosoma with abundant sub-erect hairs, petiole and gaster sparse sub-decumbent hairs and decumbent pubescence; scape and tibiae with sparse sub-decumbent hairs and dense decumbent pubescence. Whole body black-brown.

Habitat.

The specimens were found nesting under a stone in broadleaf forest and conifer mixed forest at the altitude of 1026 m.

Etymology.

This species is named from the Latin words “quadrat” (quadrate) and “nodules” (petiole), referring to its nearly square petiole.

Differential diagnosis.

The workers of Gnamptogenys quadrutinodules are distinguished from workers of other species of Gnamptogenys by the combination of the following characters: small eye, with 5 ommatidia along the maximum diameter; occipital lamella of head of head narrow and inconspicuous; petiole with anterior corner slight rounded and posterior corner bluntly angulate, node roughly sub-quadrate with dorsal and anterior margins weakly convex, posterior margin straight. Subpetiolar process sub-quadrate.

The workers of Gnamptogenys quadrutinodules are quite similar to those of Gnamptogenys coccina Zhou, 2001 and Gnamptogenys taivanensis (Wheeler, 1929). Gnamptogenys quadrutinodules can be distinguished from Gnamptogenys taivanensis by the rough rugose-punctate sculpturing of abdominal tergite III vs the diminished sculpturing on Gnamptogenys quadrutinodules , the shape of subpetiolar process seems different in the two species and the general color pattern for the workers also seems different. The distribution range of Gnamptogenys quadrutinodules may be sympatric with that of Gnamptogenys coccina (Map. 1). Most of the specimens of Gnamptogenys coccina were collected from sub-tropical forests of Guangxi Zhuang Autonomous Region, China, and once recorded from Hubei province by Wang et al. (2009). So far the location of Gnamptogenys quadrutinodules , Jiangxi province, was not found the distribution of Gnamptogenys coccina . But Jiangxi, Guangxi and Hubei Provices compose triangle-distributed. So the Gnamptogenys coccina is likely to exist in Jiangxi, and which is impossible through distribution range to roughly distinguish Gnamptogenys quadrutinodules from Gnamptogenys coccina . So far Gnamptogenys coccina has not been found in sympatry with Gnamptogenys quadrutinodules but the present records suggest the likely presence of Gnamptogenys coccina in Jiangxi Province so assuming allopatry as as a rough sorting criteria for the two species is probably not a good idea.

However, the worker of Gnamptogenys quadrutinodules is distinguished from workers of Gnamptogenys c occina by the following characters: Promesonotal suture ambiguous; 3-7 flagellar segments broader than long; in lateral view petiole roughly sub-quadrate, in dorsal view petiole broader than long; subpetiolar process sub-quadrate.

Figures

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

Figures 15 - 18. Gnamptogenys quadrutinodules holotype worker (No. G 120081). 15 head in full-face view 16 petiole in lateral view 17 body in dorsal view 18 body in lateral view.

Figures 19 - 23. Gnamptogenys quadrutinodules paratype queen (No. G 120081). 19 head in full-face view 20 forewing in dorsal view 21 hindwing in dorsal view 22 body in dorsal view 23 body in lateral view.

Figures 24 - 28. Gnamptogenys quadrutinodules paratype male (No. G 120081). 24 head in full-face view 25 forewing in dorsal view 26 hindwing in dorsal view 27 body in dorsal view 28 body in lateral view.