Hydrocanthus (Sternocanthus) balkei, Toledo & Hendrich, 2006

Toledo, M. & Hendrich, L., 2006, Taxonomic revision of the Australasian Hydrocanthus SAY 1833, with description of two new species (Coleoptera: Noteridae), Linzer biologische Beiträge 38 (1), pp. 935-952 : 937-938

Hydrocanthus (Sternocanthus) balkei sp.n. ( Figs 1 , 7 , 12 , 17 )

Type locality: Shallow, muddy pool, Kali Bobo (= Bobo River), Paniai Province, Nabire, Irian Jaya, Indonesia.

T y p e m a t e r i a l: Holotype: 1: " Irian Jaya, Paniai Prov., Nabire, Kali Bobo , 100 m, IX.1990 (IR 91 #10), leg. Balke & Hendrich" ( NMW) . Paratypes: 11 specimens with same data as holotype ( MTP, NMW) ; 14 exs.:"W-Neuguinea/ Paniai Prov. Nabire – Kali Bobo / IR 10, 19., 20. & 26.9.90 leg. Balke & Hendrich" ( CHB, MTP, OLML) .

D i a g n o s i s: Black, poorly iridescent, almost matt. Laterally quite convex; dorsal outline oval, broad near the shoulders, quite strongly tapering toward the elytral apex ( Fig. 1 ).

D e s c r i p t i o n: Holotype: total length: 6.4 mm; total length without head: 5.7 mm; maximum width: 3.0 mm. Paratypes: total length: 5.65-6.6 mm; total length without head: 5.15-5.9 mm; maximum width: 2.75-3.0 mm.

Head: brownish-black, dorsal surface with an impressed microreticulation of small, rounded meshes hardly arranged in wrinkles, together with very few sparse and fine dots. Underside and labrum dark brown, antennae and mouthparts reddish-brown.

Pronotum: pitch-black; dark-reddish toward lateral sides; without iridescence; lateral sides rounded, with bead strong and in relief, gradually narrowed to the base; anterior bead quite strong. Dorsal surface marked with wrinkles of meshes that are quite well distinguished but less so than on head.

Elytra: pitch-black, poorly iridescent, surface almost dull; maximum width behind the base, at about the first sixth of their length; lateral side, seen in lateral view, poorly concave at the shoulders. Microreticulation as on pronotum but rather more impressed. Two longitudinal, almost regular, series of dots are well visible, running practically unmodified, up to the elytral apex.

Underside: dark, reddish-brown, blackened on distal side of abdominal sternites; surface covered by a microreticulation of strong polygonal meshes, smoother on metacoxae and sternites. Prosternum and prosternal process strongly pubescent, with hair dots on prosternum more closer than on the latter. Punctuation on metasternal and metacoxal plates as on prosternal process. Legs: reddish-brown; metafemora with a row of dots along fore and hind side, the latter being irregular close to the apex.

: pro and mesotarsi with suckers, as in all member of the genus. Median lobe of aedeagus ( Fig. 7 ) quite broad, pointed apically, with transverse ridge on left side well visible. Left paramere ( Fig. 12 ) pointed distally; apical tuft of hairs forming a long curl, sharply distinguished from the other hairs.

: Similar to, not differing from male externally.

E t y m o l o g y: Dedicated to our friend and colleague Dr. Michael Balke (Zoologische Staatssammlung, Munich, Germany) who collected part of the type material.

H a b i t a t: All specimens were collected in a small, shallow and muddy pool formed by different small streams or ditches, very near the coast. The locality was in a recently burned and cultivated area.

D i s t r i b u t i o n ( Fig. 17 ): Only known from the type locality near Nabire, Irian Jaya. Probably more widespread in the lowlands along the northern coast of New Guinea. First record of the genus in New Guinea.

Figures

Figs 1-6: Habitus of: (1) Hydrocanthus balkei; (2) H. pederzanii; (3) H. australasiae; (4) H. waterhousei; (5) indicus, f. typica; (6) indicus, black form (scale: 2 mm).

Figs 7-11: Median lobes of aedeagus (left lateral view, rotated): (7) Hydrocanthus balkei; (8) H. pederzanii; (9) H. australasiae; (10) H. waterhousei; (11) H. indicus.

Figs 12-16: Left paramere (inner face, rotated): (12) Hydrocanthus balkei; (13) H. pederzanii; (14) H. australasiae; (15) H. waterhousei; (16) H. indicus.

Fig. 17: Distribution of the Australasian species of the genus Hydrocanthus (Sternocanthus) after LARSON (1993, 1997), WEIR (1998) and specimens cited in this publication. Hydrocanthus australasiae (triangles), H. waterhousei (asteriks), H. balkei (square) and H. pederzanii (dots).