Platynectes davidorum Hajek, Alarie, Stastny & Vondracek 2019

Platynectes davidorum Hájek, Alarie, Šťastný & Vondráček, 2019 (Figs 2B, 6C–D, 8A, 10A) Platynectes davidorum Hájek, Alarie, Šťastný & Vondráček, 2019: 221 (orig. descr.). Type locality. “ China, Fujian Province, Nanping Prefecture, Wuyishan Mts., Tongmu –Sangang vill.”, ca. 27°45.0′N, 117°40.7′E, 720 m. Type material. Holotype ♂, deposited in IZCAS. Material studied. CHINA: Jiangxi: 1 ♂, Shangrao, Sanqingshan Mt., 15-20.iv.2007, F. Jia leg. (SYSU); Zhejiang: 5 ♂, 10 ♀, Quzhou, Qujiang distr., Yaowangshan Mt., Shennong Waterfall, 28.7632N, 118.9731E, 340 m, 24.viii.2021, Z. Jiang & X. Ye leg. (SYSU). Notes. Habitus and male genitalia are given in Figs 2B and 6C–D. Collection details. In Yaowangshan Mt. (Zhejiang), Platynectes davidorum was collected during the day under mosses on wet rock, and at night in crevice or surface of rock covered with water film near waterfall (Fig. 8A). Distribution. Eastern China (Fujian, Jiangxi, Zhejiang) (Fig. 10A). First record from Jiangxi province. Notes. Platynectes davidorum seems to be strictly hygropetric, all specimens examined and also the type material (Hájek et al. 2019) were found in water films on rock surface. The strongly convex body and short appendages of the adults are likely adaptive features associated with this hygropetric lifestyle (Hájek et al. 2019). Besides this, another hygropetric species Hydrotrupes chinensis Nilsson, 2003, collected together with P. davidorum in Yaowangshan Mt. (Zhejiang), also displays a strongly convex body and short appendages, and furthermore absence of natatory setae on legs. These characters reflect adaptation to life on wet rock walls and limited ability to swim. Although Hydrotrupes palpalis Sharp, 1882 from North America has been shown capable of swimming (Hering 1998), individuals of this species often stay on rock surface within water films (Larson et al. 2000). The presence of natatory setae on the legs of P. davidorum may suggest that this species retains an ability to swim, as has been shown for the well-known North American hygropetric Hydrotrupes palpalis.
Published as part of Jiang, Zhuo-Yin, Zhao, Shuang, Jia, Feng-Long & Šťastný, Jaroslav, 2023, Two new species of Platynectes Régimbart, 1879 from China with notes on other Chinese members of the genus, including a key to species (Coleoptera: Dytiscidae: Agabinae), pp. 401-425 in Zootaxa 5227 (4) on page 406, DOI: 10.11646/zootaxa.5227.4.1, http://zenodo.org/record/7518878
{"references":["Hajek, J., Alarie, Y., Stastny, J. & Vondracek, D. (2019) The first hygropetric Platynectes and its larva from eastern China (Coleoptera: Dytiscidae). Acta Entomologica Musei Nationalis Pragae, 59 (1), 217 - 228. https: // doi. org / 10.2478 / aemnp- 2019 - 0019","Nilsson, A. N. (2003) A new species of Hydrotrupes Sharp from China, an example of Pacific intercontinental disjunction. In: Jach, M. A. & Ji, L. (Eds.), Water beetles of China. Vol. III. Zoologisch-Botanische Gesellschaft in Osterreich and Wiener Coleopterologenverein, Wien, pp. 279 - 284.","Sharp, D. (1882) On aquatic carnivorous Coleoptera or Dytiscidae. Scientific Transactions of the Royal Dublin Society, Series 2, 2, 179 - 1003, pls. 7 - 18. https: // doi. org / 10.5962 / bhl. title. 9530","Hering, D. (1998) Riparian beetles (Coleoptera) along a small stream in the Oregon Coast Range and their interactions with the aquatic environment. The Coleopterists Bulletin, 52, 161 - 170.","Larson, D. J., Alarie, Y. & Roughley, R. E. (2000) Predaceous diving beetles (Coleoptera: Dytiscidae) of the Nearctic Region, with emphasis on the fauna of Canada and Alaska. NRC Research Press, Ottawa, 982 pp."]}