Copelatus martinbaehri, Hendrich, Lars, Shaverdo, Helena, Hajek, Jiri & Balke, Michael, 2019

Hendrich, Lars, Shaverdo, Helena, Hajek, Jiri & Balke, Michael, 2019, Taxonomic revision of Australian Copelatus Erichson, 1832 (Coleoptera, Dytiscidae, Copelatinae), ZooKeys 889, pp. 81-152 : 81

Copelatus martinbaehri sp. nov. Figures 7 , 16 , 28

Type locality.

Moreguina (St Stephen’s Mission), Central Province, Papua New Guinea Central, 50 m, 10.018104S, 148.467793E.

Type material.

Holotype: Male, "Papua New Guinea Central, Moreguina, 18.viii.2008 Posman (PNG184)" [printed label]; "Holotype Copelatus martinbaehri sp.n. Hendrich, Shaverdo, Hajek & Balke des. 2019 [red printed label] (ZSM). Paratypes (23 specimens): Australia: 7 exs., " 12.445S, 143.14E QLD 3 km ENE Mt. Tozer 28 June– 4July 1986 D.H.Colless Malaise Trap" "ANIC Database No. 25 019356" [printed label]; "Aust. Nat. Ins. Coll." [green printed label] (ANIC, ZSM); 1 male, "N. Queensland IRON RANGE Gordon's CK. [Creek, -12.715780, 143.302092] 10.5.71 at light leg: J.G. Brooks" [hw on both label sides], "COLL. HENDRICH BERLIN" (NMW); 1 male, 1 female, "Gordon's CK [Creek, -12.715780, 143.302092] Iron RA [Range] N.Q. [North Queensland] 100' [100 m] 10.5.71 J.G. Brooks "at light" (CLH); 1 female, "Iron RA N.Q. 4.5.71 J.G. Brooks "at light" (CLH); 2 females, "Iron Range, Cape York Pen., N.-Qld 26 May– 2 June 1971 B.K. Cantrell" (QM); 2 males, 2 females, "Iron Range, Cape York Pen. N.Q. 13.-20.V.1975 K.J. Houston At light" (QDPC, ZSM). Papua New Guinea: 1 male, 1 female, same data as holotype, one male additionally with a green label "DNA M.Balke 3803" (ZSM). 2 females, "Papua New Guinea: Central, Moreguina, 16.viii.2008 Posman (PNG183)" [printed label] (ZSM). 1 male, "Papua New Guinea: Northern Kokoda, 410 m, i.2008, 53.4[?]81S 147 43.648E, Posman, (PNG 174)" (ZSM). All paratypes with our red printed labels.

Description of male holotype.

Body shape: In dorsal view, oblong-oval, broadest in basal third of elytra, moderately convex. Body outline without discontinuity between pronotum and elytra. Head relatively broad; anterior margin of clypeus not bordered. Pronotum broadest between posterior angles, lateral margins moderately curved. Base of elytra as broad as pronotal base; lateral margins of elytra moderately curved ( Fig. 7 ).

Colouration: Body black, most of clypeus, anterior angles of pronotum, base and tip of elytra, appendages and much of ventral surface testaceous.

Dorsal surface sculpture: Whole surface shiny ( Fig. 7 ). Head uniformly microreticulated, reticulation composed of moderately deeply impressed isodiametric very small meshes. Punctation composed of very small punctures spread sparsely on surface; rows of deep and coarse punctures present around inner margin of eyes and in small depression anterolaterally of eyes. Pronotum with some weak and short striae laterally. Microreticulation and punctation similar to that of head; row of coarse setigerous punctures present along anterior margin, basal margin (except for basomedially), and laterally close to sides. Elytra with microreticulation similar to that of head and pronotum, but less impressed. Punctation consisting of very fine sparse punctures. Each elytron with six strongly impressed discal and one submarginal longitudinal striae, intervals subequal, striae 1 and 5 tending to be shorter basally; submarginal stria reaching from little behind midlength of elytron almost to end of stria 6. Serial punctures on elytron untraceable.

Antennae and legs: Antenna with antennomeres long and slender. Protibia modified, distinctly broadened anteriorly (2/3rd) and strongly narrowed basally (1/3rd). Pro- and mesotarsomeres 1-3 slightly broadened, with adhesive discs on their ventral side; claws simple.

Ventral part: Finely microreticulated, with intermixed, sparsely distributed, very small punctures. Prosternal process rather flat, distinctly bordered laterally, weakly and bluntly pointed. Lateral parts of metaventrite tongue-shaped, very slender. Metacoxal lines close, well-marked and moderately divergent anteriorly. Metacoxae with long and deep striae, abdominal ventrite I with numerous striae and ventrites 2-3 with a few longitudinal striae.

Male genitalia: Median lobe sickle-shaped, narrow, simple; in ventral view, appearing somewhat flattened; in lateral view, apically tapering and strongly curved downwards ( Fig. 16B, C ). Shape of paramere broadly triangular, with weak, relatively short setae, mainly along dorsal margin of subdistal part ( Fig. 16D ).

Female.

Similar to male in habitus. Protibia not modified. Pro- and mesotarsomeres not broadened, without adhesive setae.

Measurements.

Holotype: TL = 6.35 mm; TL-H = 5.85 mm; MW = 3.1 mm. Paratypes: TL = 6.2-6.75 mm; TL-H = 5.85-6.1 mm; MW = 3.1-3.2 mm.

Variability.

All specimens studied are rather uniform in shape and size but vary a bit in the extension of the testaceous elytral markings.

Differential diagnosis.

Based on the characteristic sickle-shaped median lobe, the new species belongs to a difficult complex of species distributed in the Sunda Islands and New Guinea, including C. geniculatus Sharp, 1882, C. gentilis Sharp, 1882, C. lineatus ( Guérin-Méneville, 1838) and C. subterraneus Guéorguiev, 1978 (of the C. irinus species group) and several additional undescribed species, both from the C. irinus group (i.e., with six dorsal striae on elytra) and the C. trilobatus group (with 11 dorsal striae). All those species are rather uniform in body shape and colouration; they differ in elytral striation (which may be, however, variable) and less so in the shape of the median lobe in lateral view, especially in the width of the medial part and in length and curvature of the apical part. Copelatus martinbaehri sp. nov. differs from the other species of this complex by the shape of the median lobe, which has the central part in lateral view broader, but without distinct tubercle on the ventral side; additionally, the apical part is shorter and almost straight (the angle between central and apical part of median lobe in lateral view is nearly rectangular).

Within other Australian species with six elytral striae, Copelatus martinbaehri sp. nov. can be easily distinguished by its larger size ( C. tenebrosus is always less than 5 mm), more elongate habitus ( C. portior more ovoid, oval), elytral colouration ( C. marginatus and C. tenebrosus with almost black dorsal surface), and the shape of the median lobe.

Etymology.

This species is dedicated in honour of our late colleague Dr Martin Baehr (*10.3.1943, †17.4.2019, Munich, Germany), coleopterist, arachnologist, and others as well as the most knowledgeable authority for Australian ground beetles. The specific epithet is a substantive in the genitive case.

Distribution.

Northern Queensland (Iron Range National Park at Cape York Peninsula) and south-eastern Papua New Guinea (Central Province) ( Fig. 28 ).

Habitat.

Unknown. Most probably, the new species is an inhabitant of temporary lowland rainforest pools. The type specimens were collected in a Malaise Trap and at light.

Figures

Figure 7. Habitus and colouration of Copelatus martinbaehri sp. nov., paratype (Mount Tozer), male. Total length 6.7 mm.

Figure 16. Copelatus martinbaehri sp. nov., paratype from Mount Tozer A median lobe in lateral view, right side B median lobe in lateral view, left side C median lobe in ventral view D left paramere in external view. Scale bar: 0.5 mm.

Figures 27, 28. Distribution of 27 Copelatus tenebrosus 28 C. martinbaehri sp. nov.