Probolomyrmex vieti Eguchi, Yoshimura & Yamane, 2006

Liang, Cuijun & Chen, Zhilin, 2022, Taxonomic review of Chinese ant genus Probolomyrmex (Hymenoptera: Formicidae), Zoological Systematics 47 (2), pp. 146-154 : 153

Probolomyrmex vieti Eguchi, Yoshimura & Yamane, 2006 ( Figs 13–16 )

Probolomyrmex vieti Eguchi, Yoshimura & Yamane, 2006: 29 , figs 1–3.

Diagnosis. Petiole relatively short (LPI 110–114); posterodorsal corner shortly acutely toothed, posterior margin weakly concave; ventral margin weakly concave with a minute blunt tooth before concavity, anteroventral corner triangularly toothed.

Description of workers (n = 2, Figs 13–16 ). TL 1.9–2.0, HL 0.53–0.54, HW 0.32–0.34, CI 59–64, SL 0.26, SI 76–81, PW 0.25–0.26, MSL 0.67–0.69, PL 0.21–0.22, DPW 0.15–0.16, PH 0.23–0.25, LPI 110–114, DPI 71–73.

In full-face view, head longer than broad, anterior 1/4 narrowed, posterior 3/4 nearly rectangular, posterior margin nearly straight, lateral margin evenly convex. Mandibles small and triangular, hidden in frontoclypeal projection. Antennal scrobes degeneration, antennal sockets completely exposed, separated by vertical lamella on either side to form a frontal carina. Antennae 12-segmented, scape relative shorter, failed to reach posterior head margin by about 1/3 of its length, flagellum incrassate toward apex.

In lateral view, dorsal outline of mesosoma weakly convex at anterior 1/4 and almost straight at posterior 3/4. Propodeal teeth bluntly angled, declivity almost straight, propodeal lobe large and rounded.

Petiole relatively short, abruptly curved anteriorly, slightly convex dorsally and forming an arch, posterodorsal corner shortly acutely toothed, posterior margin weakly concave; ventral margin weakly concave with a minute blunt tooth before concavity, anteroventral corner triangularly toothed. In dorsal view, petiole narrowed anteriorly at anterior 1/2 and roughly rectangular at posterior 1/2; lateral margins weakly convex; posterior margin almost straight and complete.

Body surface finely abundantly foveolate, interface finely micro-reticulate and dim. Body dorsum with dense depressed short pubescence, without standing hairs; scapes and tibiae with dense depressed short pubescence and without standing hairs. Body light reddish brown, antennae and legs yellowish brown.

Material examined. 2 workers, CHINA: Guangxi, Nanning, Xixiang Pond , Xiangsi Lake , 22.86°N, 108.24°E, elev. 84 m, 5.IV.2020, leg. Biao Huang, No. G 200002.

Distribution. China (Guangxi), Vietnam, Cambodia, Thailand, Indonesia.

Recognition. The species is similar to P. dammermani , but can be distinguished from the latter by the relatively blunt propodeal teeth and posterodorsal corner of petiole, and by the weakly concave ventral margin of petiole ( Figs 13–16 ). The species is recorded in China for the first time.

Key to known Chinese species of Probolomyrmex based on worker castes

1. Anterodorsal outline of petiole in lateral view strongly arched ( Fig. 16 ); subpetiolar process developed and slightly rectangular ( Fig. 16 ) ......................................................................................................................................................................... P. vieti Eguchi, 2006 Anterodorsal outline of petiole in lateral view gently arched ( Figs 4 , 8 , 12 ); subpetiolar process present as a low and longitudinal ridge stripes, with an acute anterior projection and posteriorly with an arc-shaped prominence ( Figs 4 , 8 , 12 , 16 ) ............................2

2. Petiole relatively short (PL <0.34) ....................................................................................................... P. dammermani Wheeler, 1928 Petiole relatively long (PL ≥ 0.40) .......................................................................................................................................................3

3. In lateral view propodeal teeth and posterodorsal corner of petiole less prominent, close to a right angle. In dorsal view, posterior margin of petiole complete and weakly convex in dorsal view............................................ P. longinodus Terayama & Ogata, 1988 In lateral view propodeal teeth and posterodorsal corner of petiole more prominent, close to an acute angle. In dorsal view, posterior margin of petiole imcomplete, concave in middle, convex laterally and forming a pair of blunt teeth.................................................. ......................................................................................................................................................... P. longiscapus Xu & Zeng, 2000

Funding This study was supported by the National Natural Science Foundation of China (31960108), Natural Science Foundation of Guangxi (2021JJA130278) and Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education and Guangxi Key Laboratory of Rare and Endangered Animal Ecology (Guangxi Normal University) .

Acknowledgements We are grateful to Biao Huang and Liwei Liang (Guangxi Normal University, China) for collecting the ant specimens, Zhenghui Xu (Southwest Forestry University, China) and Katsuyuki Eguchi (Tokyo Metropolitan University, Japan) for valuable comments and critical editing.

Figures

Figures 13–16.Probolomyrmex vieti worker (No. G200002). 13. Head, full-face view. 14. Frontoclypeal projection and median vertical lamella, lateral view. 15. Body, dorsal view. 16. Body, lateral view.

Figures 1–4. Probolomyrmex dammermani worker (No. G200009). 1. Head, full-face view. 2. Frontoclypeal projection and median vertical lamella, lateral view. 3. Body, dorsal view. 4. Body, lateral view.

Figures 5–8. Probolomyrmex longinodus worker (No. G160136). 5. Head, full-face view. 6. Frontoclypeal projection and median vertical lamella, lateral view. 7. Body, dorsal view. 8. Body, lateral view.

Figures 9–12. Probolomyrmex longiscapus worker (No. G130918). 13. Head, full-face view. 14. Frontoclypeal projection and median vertical lamella, lateral view. 15. Body, dorsal view. 16. Body, lateral view.