Gauromyrmex acanthinus ( Karavaiev, 1935 )

Chen, Defu & Chen, Zhilin, 2022, Ants of the genus Gauromyrmex Menozzi (Hymenoptera: Formicidae), with description of a new species from China, Asian Myrmecology (e 015007) 15, pp. 1-10 : 6-7

Gauromyrmex acanthinus ( Karavaiev, 1935) ( Figs. 1–9 )

Solenomyrma acanthina Karavaiev, 1935: 103 , fig. 23 (w.) VIETNAM. Combination in Gauromyrmex by Brown, 1953: 10; in Vollenhovia by Bolton, 1995: 422; in Gauromyrmex by Bolton, 2003: 269 (Not examined).

Acalama donisthorpei Smith, M.R. 1949: 207 , figs. 1, 2 (w.) INDIA. Synonymized by Brown, 1953: 10 (Images of two paratype workers examined, CASENT0172784 & CASENT0172785, https://www.antweb.org/, images by April Nobile).

Material examined. 5 workers, CHINA: Hunan, Liuyyang, Daweishan, 1.IX.2004, leg. Jianhua Huang; 1 worker, Guangxi, Longlin , Jinzhongshan Protection Zone, 7.III.2014, leg. Zhilin Chen, No. G140110; 1 worker, Yunnan, Kunming, Panlong District, Longtan Park, 1. VI.2013, leg. Jianyue Qiu, No. G137852.

Diagnosis. Anteromedian margin of clypeus concave in full-face view, with lateral part forming a pair of weak lobes; promesonotal dorsum in lateral view convex; posterodorsal corner of propodeum with a triangular tooth and declivity concave; in dorsal view, humeral corners of pronotum with a pair of distinct teeth.

Description. Worker. TL 2.4–2.7, HL 0.57–0.66, HW 0.53–0.63, CI 91–100, SL 0.36–0.38, SI 60–64, ED 0.12–0.14, PW 0.34–0.41, MSL 0.61–0.75, PL 0.17–0.20, PH 0.13–0.16, DPW 0.12–0.15, LPI 72–89, DPI 72–79 (n=7).

Head. Head in full-face view slightly longer than broad, posterior margin weakly concave; eyes median size and weakly convex, located in front of midpoint of lateral margin of head; frontal carina and antennal scrobes absent; mandibles triangular, masticatory margin with 6 teeth, with a large apical tooth, followed by a smaller preapical tooth and 4 denticles; anteromedian margin of clypeus concave, with lateral part forming a pair of weak lobes. Mesosoma. Promesonotal dorsum in lateral view convex and higher than metanotum; promesonotal suture absent; metanotal groove concave; propodeum dorsum convex and gradual decline posteriorly, posterodorsal corner with a triangular tooth; propodeal lobes with a blunt posterior margin. In dorsal view, humeral corners of pronotum with a pair of distinct teeth; lateral sides of pronotum almost straight and convergent posteriorly; posterodorsal corner of pronotum with a pair of blunt processes, and not passing smoothly to lateral margins of mesonotum; promesonotal suture absent, but sometimes with a faint trace ( Figs. 2, 5, 8 ); anterior margin of mesonotum convex, lateral margin weakly convex and convergent posteriorly; metanotal groove depressed, and strongly constricted between mesonotum and propodeum; lateral margin of propodeum convex, posterior margin concave, posterolateral corner forming a pair of blunt teeth. Waist. Anterodorsal corner of petiole forming a small tooth which points forward and upwards; dorsum with a thick tooth slightly curving backwards; subpetiolar process triangular transparently; in dorsal view, petiole rectangular, blunt denticle in anteriolateral corner, with a transverse ridge in middle. Postpetiole in lateral view smaller than petiole, dorsal margin strong convex, sternite of postpetiole much smaller than its stergite, anteroventral corner with an obtuse angle; in dorsal view anterolateral corner of postpetiole rounded, lateral margin almost straight and weakly convergent posteriorly. Gaster. Gaster in lateral view oval, in dorsal view humeral corner of gaster obtuse-angulate. Sculpture. Mandibles scattered with piligerous punctures; frontal lobes with longitudinal stria, which sometimes extending backward to a half of head; cheek with longitudinal stria; the rest of the head smooth and shiny, except scattered with piligerous punctures; middle part of mesonotum and propodeum smooth and shiny, but with their lateral parts rugulose; face of metanotal groove scattered with ridges; lateral face of pronotum and upper part of propodeum smooth and shiny, lower part of propodeum reticulate-rugulose; gaster smooth and shiny. Pilosity. Body with dense erect hairs and sparse pubescence, antennae with abundant pubescence. Color. Body yellow to yellow-brown.

Remarks. This species is easily distinguished from the congeners of this genus by notably dentate shoulder of pronotum.

Distribution. China ( Wu & Wang 1995; Huang & Zhou 2006; Terayama 2009; General & Alpert 2012; Cheng et al. 2015; Yu et al. 2019), India ( Bharti et al. 2016), Vietnam ( Karavaiev 1935; Eguchi et al. 2011), Thailand ( Jaitrong & Jeenthong 2015; Khachonpisitsak et al. 2020).

Figures

Figs. 1 – 9. Gauromyrmex acanthinus worker. 1, 4, 7. Head in full-face view; 2, 5, 8. Body in dorsal view; 3, 6, 9. Body in profile view.