Anochetus risii Forel, 1900

Chen, Zhilin, Yang, Zhigang & Zhou, Shanyi, 2019, Review of the ant genus Anochetus Mayr, 1861 (Hymenoptera, Formicidae) from China, with revival of the valid status of Anochetus gracilis, Journal of Hymenoptera Research 68, pp. 49-74 : 49

Anochetus risii Forel, 1900

Figs 7 , 8 , 9

Anochetus risii Forel, 1900: 60. [Syntype worker images examined, AntWeb, CASENT0907411, photos by Will Ericson].

Anochetus taiwaniensis Terayama, 1989: 26. [Two paratype worker images examined, AntWeb, CASENT0915167 & CASENT0902440, photos by Will Ericson]. Syn. n.

Non-type material examined.

1 worker, CHINA, Guangxi, Jinzhongshan Natural Reserve, 7.VIII.2014, leg. Zhilin Chen, No. G140447; 5 workers, CHINA, Guangxi, Beiliu City, Liuma Town, Sanhemaoping, 22. IV.2015, leg. Zhilin Chen; 1 worker, CHINA, Guangdong, Yingde City, Shimentai, 14.VIII.2000, leg. Jianhua Huang; 1 worker, CHINA, Guangdong, Nankunshan, 11.VII.2009, leg. Xinbing Yan; 2 workers, CHINA, Guangxi, Nonggang, 14.X.2007, leg. Chang Lin, No. G070219; 1 worker, CHINA, Hunan, Anhua Country, Hongyan, 14.VII.2004, leg. Jianhua Huang.

Workers.

TL 5.12-5.34, HL 1.67-1.69, HW 1.44-1.46, CI 85-87, SL 1.55-1.57, SI 106-108, ED 0.11-0.12, PW 0.80-0.82, MSL 2.33-2.36, PL 0.37-0.39, PH 0.74-0.76, DPW 0.30-0.32, LPI 202-207, DPI 83-85 (n = 5).

In full-face view head longer than broad, posterior margin strongly concave. Mandibles linear, gradually broadened apically; inner margin with several denticles, gradually decreasing in size towards base; apical portion with three distinct teeth. Antennae 12-segmented; scapes surpassing to posterior corners of head by about 1/5 of its length. Eyes large, maximum diameter of eye wider than the basal width of mandibles.

In lateral view mesosoma slender. Pronotum weakly convex. Promesonotal suture shallowly impressed. Mesonotum weakly convex, sloping posteriorly. Metanotal groove deeply concave. Dorsum of propodeum almost straight, posterodorsal corner bluntly angled. Petiole cone-shaped and slightly inclined posteriorly, with a pointed dorsal apex, anterior margin weakly convex, posterior margin almost straight; subpetiolar process triangular, directed posteroventrally.

Frons longitudinally to obliquely striate posteriorly; frontal lobes and clypeus weakly striate, remainder of head smooth and shining. Mesosoma smooth and shining, propodeum and lower part of metapleuron obliquely rugose. Sometimes sides of pronotum weakly longitudinal rugose. Petiole smooth and shining, basal area weakly striate. Gaster smooth and shining. Body dorsum with abundant erect to suberect hairs and dense decumbent pubescence; scapes and tibiae with scattered suberect hairs and dense decumbent pubescence. Body blackish brown; antennae and legs yellowish brown.

Recognition and discussion.

After detailed comparison of type worker images of A. risii (CASENT0907411) and A. taiwaniensis (CASENT0902440 & CASENT0915167), we noticed that both species have completely consistent characters in head, mandibles, antennae, eyes, mesosoma, petiole and measurement range. Terayama (1989) pointed out that A. taiwanensis is distinguished from A. risii by "broader mandibular shafts and small denticles of the dorsal inner margin of the mandible in the former". However, we are unable to recognize these differences. The only difference between them is that A. taiwaniensis has the pronotum weakly rugose laterally. Consequently, we consider it safe to propose A. taiwaniensis as a junior synonym of A. rissi here.

Distribution.

Known from Vietnam, Indonesia and Southern China.

Figures

Figure 7. Anochetus risii worker (No. G 140447). A head in full-face view B mandible in anterior view C body in dorsal view D body in lateral view.

Figure 8. Anochetus risii worker (Syntype, AntWeb, CASENT 0907411, photos by Will Ericson). A head in full-face view B labels C body in dorsal view D body in lateral view.

Figure 9. Anochetus taiwaniensis, syn. n. (Paratype, AntWeb, CASENT 0915167, photos by Will Ericson). A head in full-face view B labels C body in dorsal view D body in lateral view.