Research Article |
Corresponding author: Michael Balke ( balke.m@snsb.de ) Academic editor: Mariano Michat
© 2017 Michael Balke, Johannes Bergsten, Liang-Jong Wang, Lars Hendrich.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Balke M, Bergsten J, Wang L-J, Hendrich L (2017) A new genus and two new species of Southeast Asian Bidessini as well as new synonyms for Oceanian species (Coleoptera, Dytiscidae). ZooKeys 647: 137-151. https://doi.org/10.3897/zookeys.647.11231
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Rompindessus jenisi Balke, Bergsten & Hendrich, gen. n. et sp. n. is described from near Rompin village in West Malaysia. The new genus is characterized by the presence of an occipital line and basal pronotal striae, the presence of a thick anterior bead on clypeus and two-segmented parameres as well as by the absence of basal elytral striae, the absence of sutural line on elytron, the absence of basal epipleural transverse carina, and the absence of longitudinal elytral carina. Moreover, male pro- and mesotarsus appear stout, and distinctly dilated laterally; the pronotum is comparably long and parallel-sided and the colour of beetle conspicuous dark orange. Leiodytes kualalipis Balke, Wang, Bergsten & Hendrich, sp. n. is described from West Malaysia (Pahang) and South Vietnam (Cat Tien). It is well characterized by its large size, elongate body and the form of the median lobe. Limbodessus fijiensis (J. Balfour-Browne, 1944), comb. n. described from Fiji is a new synonym of Limbodessus curviplicatus (Zimmermann, 1927) described from Samoa.
Bidessini , Dytiscidae , new combination, new genus, new species, new synonymy, Oceania, Southeast Asia
There are currently 48 genera in the Bidessini (
Drawings of the male genitalia were made based on digital images. The beetles were studied with a Leica MZ 12.5 stereomicroscope at 10–100x and a Scanning Electron Microscope (JSM-5600. JOEL, Tokyo, Japan) at 90–1000X. The terminology to denote the orientation of the genitalia follows
BMNH
CSR Collection Saverio Rocchi, Firenze, Italy
CWT Collection L. J. Wang, Taipei, Taiwan
Rompindessus jenisi sp. n. by present designation.
Of the set of structural features generally used to classify Bidessini, the following combination is present in this taxon: 1) occipital line present; 2) basal pronotal striae present; 3) basal elytral striae absent; 4) sutural line on elytron absent; 5) basal epipleural transverse carina absent; 6) clypeus with thick anterior bead (or margin); 7) longitudinal elytral carina on disc absent; and 8) parameres two-segmented. Moreover, the male pro- and mesotarsus appear stout, and distinctly dilated laterally; the pronotum is comparably long and parallel-sided and the colour of beetle is conspicuously dark orange. This differentiates Rompindessus gen. n. from all other Bidessini. In the key to Bidessini genera by
Named after the collecting locality, Rompin village, and the ending – dessus as used for many genera in Bidessini.
Male (
Situated around Malaysia, Pahang, Selendang, between these points 2.622516°N 103.334934°E / 2.609909°N 103.382443°E / 2.643574°N 103.409337°E, it is not known where exactly this particular beetle was discovered. The altitude is around 50 to 250m (Jeniš pers. comm.). According to satellite images in Google Earth, the lower elevations are now heavily transformed into oil palm plantations.
Habitus elongate oval. Measurements: TL = 2.45 mm, TL-H = 2.15 mm; MW = 1.1 mm; elytra 3.5× longer than pronotum.
Colouration. Head, pronotum and elytron dark orange, the latter with few darker speckles (Fig.
Surface sculpture. Head with distinct microreticulation posterior of occipital line; finer microreticulation along eyes and clypeus, frons without microreticulation and thus shiny / polished but with few setiferous punctures. Pronotum and elytron with distinct microreticulation and sparse setiferous punctation. Ventral surfaces polished, with faint and sparse setiferous punctation.
Structures. Head with distinct occipital line and broadly beaded clypeus (Fig.
Male. Median lobe of aedeagus simply curved (Fig.
Female. Unknown.
Named after Ivo Jeniš, discoverer of this species. The specific epithet is a substantive in the genitive case.
Only known from the type locality.
Unknown.
Hydroporus evanescens Boheman, 1848
Very small, yellowish diving beetles (1.4–2.2 mm for the known species, 2.7 mm with the new one described below) with black markings on elytra. Shape of body globular to elongate, widest in middle, not flattened. 1) Occipital line present; 2) basal pronotal striae present; 3) basal elytral striae present; 4) sutural line on elytron absent; 5) basal epipleural transverse carina absent; 6) clypeus with fore margin narrowly and finely bordered, sometimes unmodified; 7) longitudinal elytral carina on disc absent; and 8) parameres two-segmented.
Includes 27 species (
Male (
The type locality was around 4.200104°N 102.061570°E, altitude 100m. The entire region is now heavily transformed into oil palm plantations. The paratype locality was in Nam Cat Tien National Park, as a rough reference we obtained a position at the forest border 11.422096°N 107.427578°E.
Habitus elongate oval. Measurements: TL = 2.7 mm; TL-H = 2.4 mm; MW = 1.3 mm; elytra 4.2× longer than pronotum.
Colouration. Beetle dark yellow with few darker basal pronotal markings and darker pattern on elytra (Fig.
Surface sculpture. Head with distinct microreticulation posterior of occipital line; faint to extremely faint microreticulation along eyes and clypeus, frons without microreticulation and thus shiny / polished but with few setiferous punctures. Pronotum and elytron without microreticulation but with dense, coarse setiferous punctation. Ventral surfaces mostly polished, metaventrite, metacoxa and ventrites 1–3 with large punctures bearing short setae, distance between punctures approximately the diameter of a single puncture (similar to Leiodytes vietnamensis Wang, Satô & Yang, 1998, p. 165, Fig.
Structures. Head with faint occipital line and depressed before clypeus leading to the impression that the clypeus is broadly beaded (Figs
Male. Median lobe of aedeagus in lateral view thin and pointed apically, apical portion spatulate in ventral view (Figs
Female. Similar to male, but surface dull due to presence of strong microreticulation dorsally and ventrally (Figs
This is the largest species of Leiodytes and well characterised by its size as the other species in the region are distinctly smaller (below 2.2 mm or even below 2 mm long, see e.g.
This is, to our knowledge, the second species reported from the Malayan Peninsula, L. nicobaricus (Redtenbacher, 1867) being the other one (
Named after the type locality, Kuala Lipis Town. The species name is a noun in apposition.
A species with a wide geographic range, known from the type locality in West Malaysia as well as from Southern Vietnam. The distance between these two localities is roughly 1,000 km measured as a straight line across the Gulf of Thailand.
The holotype was collected in shallow water, among dense layers of rotten leaves, in a shaded forest pool situated in an old rubber plantation overgrown by secondary forest (Fig.
In Vietnam, the species was collected in shallow water made by jeep on a path. Syntopically occurring dytiscid species included Leiodytes nicobaricus (Redtenbacher, 1867), Hydroglyphus orientalis (Clark, 1863) and Sandracottus maculatus (Wehncke, 1876).
We can however rule out that any of the new species proposed herein is conspecific with Hydroporus aberrans.
The other species of unclear generic placement was Hydroporus fairmairei Branden, 1885, which we transfer to Limbodessus below.
Bidessus curviplicatus Zimmermann, 1927:16 (Samoa).
Limbodessus
curviplicatus
(Zimmermann, 1927):
= Hydroporus dorsoplagiatus Fairmaire, 1881: 249 (Fiji); preoccupied by Fairmaire (1880: 247), syn. n.
= Hydroporus fairmairei Branden, 1885: 53 (a replacement name for H. dorsoplagiatus Fairmaire, 1881); this replacement name is in turn preoccupied by Hydroporus fairmairei Leprieur (1876: 142, currently in Deronectes), objective synonym of Hydroporus dorsoplagiatus Fairmaire, 1881.
= Bidessus fijiensis J. Balfour-Browne, 1944: 99 (Fiji), syn. n.
Liodessus
fijiensis
(J. Balfour-Browne, 1944):
Limbodessus fijiensis (J. Balfour-Browne, 1944), comb. n.
Hydroporus dorsoplagiatus: not located. A loan request was sent to
Bidessus curviplicatus: Holotype, male (BMNH) and paratype, male (
Bidessus fijiensis: Holotype, female (BMNH) Namaka, C Fiji 1545, 8.12.43, R.A. Lever, Pres. By Imp. Inst. Ent. B.M. 1945.9, Bidessus fijiensis Type! J. Balfour-Browne det.
8 exx (
A stout, yellow to yellow orange Limbodessus with slightly enlarged male antenna and distinct angle between base of elytron and base of pronotum (Fig.
We have not seen type material of Hydroporus dorsoplagiatus but have collected specimens in Fiji that match the description by
Samoa, Fiji.
We thank Ivo Jeniš (Prague) for valuable comments on his collecting sites in West Malaysia, Christine Taylor (BMNH, London), Manfred Jäch (