Scelimena guangxiensis Zheng, 1993

Lao, Chuangyu, Kasalo, Niko, Gao, Fan, Deng, Weian & Skejo, Josip, 2022, Review of the Chinese species of the genus Scelimena Serville, 1838 (Tetrigidae Scelimeninae: Scelimenini), Zootaxa 5200 (4), pp. 321-343 : 329-332

2. Scelimena guangxiensis Zheng, 1993 ( Figs. 6 , 7 , 8 )

Scelimena rosacea (nec Hancock): Muhammad et al., 2018: Fig. 13 (misidentification).

Type locality. PR CHINA: Guangxi ( Red Banner Forest Farm) ( Zheng 1993, Zheng & Jiang 1994) .

Type material examined. Holotype ♂, deposited in the Institute of Zoology , Shaanxi Normal University, Shaanxi, PR China.

Distribution and habitat. Scelimena guangxiensis inhabits streams and rivers of the Guangxi Province (Shangsi County, Jiuwan Shan, Mulun Nature Reserve) and possibly the southern part of the Yunnan Province of the PR China ( Deng 2016, this study). Orthoptera Species File database ( Cigliano et al. 2022) did not contain information on the type specimen/series nor on its depository hitherto. The male holotype of S. guangxiensis was collected in the Red Banner Forest Farm in 1991 and is deposited in the Institute of Zoology, Shaanxi Normal University (Shaanxi, PR China). Deng (2016) lists four localities for the examined 19 male and 38 female specimens of this interesting species. The tropical monsoon forests of the southern Guangxi provide S. guangxiensis with suitable temperature and high humidity. Adults observed in this study were found from June to July in Fangchenggang Shiwandashan Mountain, but literature records date also from August and October ( Tab. 1 .). According to other observations on, iNaturalist adults can occur as early as March (https://www.inaturalist.org/observations/108948433). Individuals can be observed on mossy rocks on the shores of rocky creeks in the mountainous tropical rainforest, usually at an altitude about or over 100 meters. Algae and moss that usually grow on rocks in and out of water probably represent a component of their diet. This species also inhabits northern Vietnam. The record of Scelimena rosacea ( Hancock 1915) from Vietnam ( Muhammad et al. 2018) undoubtedly belongs to S. guangxiensis ( Fig. 6c, 6d ).

Variability. Like any other Scelimena , the Guangxi Pygmy Rowerhopper is a relatively large tetrigid adapted for a semiaquatic lifestyle. Pronotum length in males reaches> 19 mm and in females> 20 mm ( Liang & Zheng 1998; this study). The body is covered with fine granules, but is generally smooth, much smoother than in, for example, S. melli ( Zha et al. 2017) . The vertex is narrower than a single eye, giving a large appearance to the eyes. Other species of the S. ( bellula ) species group also have a very narrow vertex ( Muhammad et al. 2018). This species has smooth and slender femora with weak undulations, but without teeth. Pronotum exceeds the knees of hind femora by about 1 hind femur length, while in this measure equals about 1.5. Antegenicular and genicular teeth are very small and blunt in appearance, almost unrecognizable. Some specimens of S. guangxiensis have more recognizable interhumeral carinae ( Fig. 8e–g ) than others ( Fig. 8a–d ). With this character, S. guangxiensis stands between S. bellula which completely lacks interhumeral carinae ( Storozhenko & Dawwrueng 2015) and S. melli , in which they are distinct ( Liang & Zheng 1998, Deng 2016). The two strongest projections are the second frontolateral and ventrolateral spines, which are also the brightest in colour. Two colour variants of the pronotum were observed in living specimens of Scelimena guangxiensis , both very bright. One variant has a combination of red and yellow, where the frontolateral first and second projections (FL1 and FL2), the second prolateral projection (PL2), and the external lateral carina above the tegmina are red ( Fig. 8c ); and the ventrolateral spine (VL), median carina and the rest of the external lateral carina are yellow. The other variant has all the aforementioned structures covered in yellow ( Fig. 8e–g ). In the original description, the colour of the specimen is stated to be dark (Zheng & Jiang 1994), but with newly reported specimens, we see that the colour pattern might have been lost because of drying in museum specimens.

Figures

FIGURE 6. Colour variations in Scelimena guangxiensis Zheng, 1993 from China (a, b) and Vietnam (c, d). The specimens from Vietnam were wrongly identified as S. rosacea by Skejo in Muhammad et al. (2018). Drawn after the specimens observed by Chuangyu Lao (a, b), and specimens from Vietnam deposited in the Institut Royal des Sciences Naturelles de Belgique collected by Jerome Constant (c, d). Scale bar – 10 mm.

FIGURE 7. Habitat of Scelimena guangxiensis Zheng, 1993. (a, b) Environment and microhabitat in Qixingding shan; (c, d) Environment and microhabitat in Shiwandashan; (e) A creek; (f) Forest beside the creek, (g) The shore of the creek; (h) A mossy rock. Photo Chuangyu Lao.

FIGURE 8. Variability of Scelimena guangxiensis Zheng, 1993. (a) A living specimen in nature with projections marked; (b–d) Specimen with red and yellow colouration, which did not manage to successfully dry the tip of the pronotum after the final moult; (e–g) Specimen with only yellow colouration. FL1 – first frontolateral projection, FL2 – second frontolateral projection, PL2 – second prolateral projection, VL – ventrolateral projection. Photo by Chuangyu Lao.