Microdytes dimorphus 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 dimorphus Wewalka, 1997

Fig. 20

Microdytes dimorphus Wewalka, 1997: 22; Wewalka 2011: 37; Nilsson and Hájek 2023: 211.

Type locality.

Thailand, Nakhon Ratchasima or Nakhon Nayok Province, Khao Yai NP.

Material examined.

Thailand: Chonburi Province. 1♂, Si Racha District, Bang Phra St. 269 (alt. 90 m), 26.XII.2020, R. Okada leg. (CRO) (Fig. 20 ) .

Comments.

Microdytes dimorphus was described based on a single male specimen from Khao Yai National Park and no additional records are known so far. Therefore, this is the second record of this species. Wewalka (1997) suggested M. dimorphus is more closely related to M. menopausis Wewalka, 1997 (Fig. 27 ) but differs by having coarser punctures on the elytra similar in size, a punctured abdomen, a more produced clypeus, and larger second segment of antennae. The specimen examined in this study corresponds with M. dimorphus due to the status of punctures on the elytra and abdomen, although the characteristics of clypeus and antenna are intermediate between M. dimorphus and M. menopausis . This species can be distinguished from M. menopausis in having a more slender body shape and indistinct elytral markings at both shoulders and post-median part (Fig. 20 ).

Distribution.

Thailand: Khao Yai NP [Nakhon Ratchasima or Nakhon Nayok Province] and Chonburi (first record) Province.

Figures

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.