Hydraena, FROM

Jäch, Manfred A., Díaz, Juan A. & Skale, Andre, 2013, The Hydraenidae (Coleoptera) Of The Republic Of Singapore, Raffles Bulletin of Zoology 61 (1), pp. 53-71 : 70-71

publication ID	https://doi.org/ 10.5281/zenodo.5351598
persistent identifier	https://treatment.plazi.org/id/03AF8781-EA2C-292E-CF01-B8A51F2EDB64
treatment provided by	Tatiana
scientific name	Hydraena
status

Treatment

KEY TO THE SPECIES OF HYDRAENA FROM View in CoL SINGAPORE

1. Punctures of dorsal surface, especially pronotum and elytra small and shallow, elytal interstices not convex ( Figs. 1, 3, 4 View Figs ). Body length: 1.05–1.50 mm ...................................................2

– Punctures of dorsal surface, especially pronotum and elytra, moderately large, dense and well impressed, elytral interstices convex ( Fig. 2 View Figs ). Body length: 1.25–1.50 mm ........................4

2. Mesoventral process ( Fig.12 View Figs ) wider than mesotibia.Metaventral plaques present or absent. Body length: 1.05–1.50 mm ........3

– Mesoventral process ( Fig. 13 View Figs ) not wider than mesotibia. Metaventral plaques absent. Body length: 1.05–1.25 mm ....... ...................................................................... H. singaporensis View in CoL

3. Middle of pronotum darkened (except for teneral specimens). Metaventral plaques present, distinctly convergent anteriorly ( Fig. 12 View Figs ). Male: foretibia slightly curved, not dilated, with subapical denticle on mesal face. Female tergite X and gonocoxite ( Fig. 6e, f View Fig ) more transverse, laterally more rounded. Body length: 1.25–1.50 mm ............................... H. hendrichi View in CoL

– Middle of pronotum not darkened. Metaventral plaques absent. Male: foretibia not curved, dilated (lateral view), without denticle. Female tergite X and gonocoxite ( Fig. 7e, f View Fig ) less transverse, laterally less rounded, apically subacuminate. Body length: 1.05–1.20 mm ................................................ H. yangae View in CoL

4. Male: Metaventral plaques thin, carinate ( Fig. 14 View Figs ). Aedeagi as in Figs. 8a–c View Fig or 9a–c. Female: Abdominal sternite VIII produced apically (see Jäch & Díaz, 1999: Fig. 7d View Fig ) or gonocoxite small, subquadrate ( Fig. 9f View Fig ).................................5

– Male: Metaventral plaques unmodified. Aedeagi as in Figs. 10a–c View Fig or 11a–c. Female: Abdominal sternite VIII apically never produced; gonocoxite transverse, lateral margin distinctly convex subbasally ( Figs. 10e View Fig , 11e View Fig )........................6

5. Maxillary palpi never darkened subapically. Aedeagus Yshaped ( Fig. 8a–c View Fig ). Female: Abdominal sternite VIII produced apically (see Jäch & Díaz, 1999: Fig. 7d View Fig ) .. H. michaelbalkei View in CoL

– Maxillary palpi usually slightly darkened subapically. Aedeagus not Y-shaped (see Fig. 9a–c View Fig ). Female: Abdominal sternite VIII not produced apically........................ H. formula View in CoL

6. Male foretibia slightly curved, without denticle. Aedeagus as in Fig. 10a–c View Fig , ventral margin of main piece with conspicuous denticle near insertion of left paramere; apex of main piece not wide in ventral view. Female tergite X ( Fig. 10f View Fig ) less transverse. Gonocoxite ( Fig. 10e View Fig ) more transverse.................. .............................................................................. H. jacobsoni View in CoL

– Male foretibia not curved, provided with very small denticle on mesal face near apical 0.3. Aedeagus as in Fig. 11a–c View Fig , ventral margin of main piece without conspicuous denticle; apex of main piece very wide in ventral view. Female tergite X ( Fig. 11f View Fig ) more transverse. Gonocoxite ( Fig. 11e View Fig ) less transverse ...................................................... H. paulmoritz View in CoL