Microdytes balkei Wewalka, 1997

Okada, Ryohei, Jaitrong, Weeyawat & Wewalka, Guenther, 2023, A review of Microdytes J. Balfour-Browne, 1946 from Thailand, Laos, and Cambodia with descriptions of five new species and new records (Coleoptera, Dytiscidae), ZooKeys 1159, pp. 87-119 : 87

Microdytes balkei Wewalka, 1997

Figs 17 , 19 , 39D

Microdytes balkei Wewalka, 1997: 18; Wewalka 2011: 29; Nilsson and Hájek 2023: 211.

Type locality.

Thailand, Rayong Province, Khao Chamao NP.

Material examined.

Thailand: Mukdahan Province. 1♂, Phu Pha Thoep N.P., small pools (23), 1.I.2000, Mazzoldi leg. (CGW) ; Ubon Ratchathani Province. 1♂, 1♀, Nam Yuen District, Dom Pradit St. 240 (alt. 260 m), 22.V.2021, R. Okada leg. (CRO, THNHM) ; Saraburi Province. 1♀, Kaeng Khoi District, Ched Khot St. 122 (alt. 140 m), 30.V.2020, R. Okada leg. (CRO) ; Chonburi Province. 2♂♂, 1♀, Ban Bueng District, Khlong Kiu St. 261 (alt. 200 m), 6.XI.2021, R. Okada leg. (CGW, CRO) (Fig. 17 ) ; 2♂♂, 1♀, Si Racha District, Bang Phra St. 269 (alt. 90 m), 26.XII.2021, R. Okada leg. (CRO) ; Rayong Province. 4♂♂, Wang Chan District, Pa Yup Nai St 299 (alt. 200 m), 17.VII.2022, R. Okada leg. (CRO, THNHM) .

Laos: Savannakhet Province. 203 exs., Phou Xang He NBCA, ca. 5 km SW Ban Pa Phaknau, 17°00'N, 105°38'E, alt. 250-400 m, 31.V.-6.VI. 2011, NHMB Basel , Laos 2011 Expedition, M. Brancucci, M. Geiser, D. Hauk, Z. Kraus, A. Phantala & E. Vongphachan leg. (CGW, CRO, NMB, NMP); Sekong Province. 3♀♀, ca. 51 km N Sekong (river) Ho Chi Minh trail, 15°49.6'N, 106°39.8'E, alt. 410 m, 14.-15.V.2010, J. Hájek leg. (NMP) .

Cambodia: Koh Hong Province . 12 exs., 20 km SW Koh Hong, Tatai River, 11°34'N, 103°07'E, alt. 50-300 m, 3.-19.V.2005, E. Jendek & O. Šauša leg. (CGW, NMB) .

Comments.

Since the figure of the median lobe of this species was not depicted clearly in Wewalka (1997), we present a new figure of the aedeagus including parameres (Fig. 17 ).

Distribution.

Thailand: Mukdahan, Rayong, Trat, Ubon Ratchathani (first record), Saraburi (first record), and Chonburi (first record) provinces, Khao Yai NP [Nakhon Ratchatsima or Nakhon Nayok Province]; Laos (first record): Savannakhet and Sekong provinces; Cambodia (first record): Koh Hong Province.

Figures

Figure 17. Microdytes balkei A median lobe in ventral aspect B median lobe in lateral aspect C left paramere in lateral aspect D right paramere in medial aspect. Scale bar: 0.25 mm.

Figures 18 - 37. Habitus of 18 Microdytes akitai 19 M. balkei 20 M. dimorphus 21 M. feryi (paratype, from Myanmar) 22 M. franzi 23 M. gabrielae 24 M. heineri 25 M. maculatus 26 M. mariannae 27 M. menopausis 28 M. paoloi 29 M. pasiricus 30 M. pederzanii 31 M. rocchii 32 M. schoedli 33 M. schoenmanni (from Myanmar) 34 M. schwendingeri 35 M. shepardi 36 M. shunichii 37 M. zetteli. Scale bar: 1.0 mm.

Figures 38 - 40. Diagnostic characters of Microdytes species. 38 Impression of lateral side (M. maximiliani sp. nov.) 39 ventral surface A with setae (M. heineri) B with very coarse punctures (M. schoedli) C with coarse punctures (M. maculatus) D with fine punctures (M. balkei) E with very fine punctures (M. jeenthongi sp. nov.) 40 clypeus bead A not bordered (M. ubonensis sp. nov.) B finely bordered (M. schwendingeri) C produced (M. dimorphus).