Exocelina warahulenensis Shaverdo & Balke

Shaverdo, Helena, Surbakti, Suriani, Warikar, Evie L., Sagata, Katayo & Balke, Michael, 2019, Nine new species groups, 15 new species, and one new subspecies of New Guinea diving beetles of the genus Exocelina Broun, 1886 (Coleoptera, Dytiscidae, Copelatinae), ZooKeys 878, pp. 73-143 : 73

16. Exocelina warahulenensis Shaverdo & Balke sp. nov. Figs 37 , 42

Exocelina undescribed sp. MB0265: Toussaint et al. 2014: supplementary figs 1-4, tab. 2; Toussaint et al. 2015: supplementary figs S1, S2, tab. S3, and information S5, S6.

Type locality.

Papua New Guinea: Simbu Province, Crater Mountain, Haia, ca. 06°39'39.9"S, 145°00'28.4"E, 700 m a.s.l.

Type material.

Holotype: male "Papua New Guinea: Crater Mountain, Haia, 700m, 11IX2002, Balke & Sagata, (PNG 001)" (ZSM). Paratypes: Simbu: 12 males, 7 females with the same label as the holotype (NHMW, ZSM). 2 males "PAPUA NEW GUINEA: Simbu / EHPr. Crater Mountain, Haia, 700m, 11IX2002, Balke & Sagata, (PNG 1)", "258 DNA M Balke" [green], "259 DNA M Balke" [green] (ZSM). 2 males, 4 females "Papua New Guinea: Crater Mountain, trek Haia - Wara Sera, 500m, 12IX2002, Balke & Sagata, (PNG 004)" (ZSM). 5 males, 3 females "Papua New Guinea: Crater Mountain, trek Haia - Wara Sera, 500m, 12IX2002, Balke & Sagata, (PNG 005)" (NHMW, ZSM). Simbu/Eastern Highlands: 1 male "265 DNA M Balke" [green], "PNG Simbu / EHPr. Crater Mountain, Sera - Herowana, Wara Hulene, 1000 m, 16IX2002, Balke & Sagata (PNG 17)" (ZSM).

Description.

Body size and form: Beetle small to medium-sized: TL-H 3.4-3.9 mm, TL 3.7-4.3 mm, MW 1.8-2.2 mm (holotype: TL-H 3.9 mm, TL 4.3 mm, MW 2.1 mm), with oblong-oval habitus.

Colouration: Piceous, with reddish sides of pronotum and head. Head reddish to reddish brown, darker posterior to eyes. Pronotum brown to piceous on disc and reddish to reddish brown on sides. Elytra dark brown to piceous. Head appendages and legs proximally yellowish, legs distally darker, reddish brown ( Fig. 37 ). Teneral specimen paler.

Surface sculpture: Shiny dorsally, with inconspicuous punctation and weakly impressed microreticulation. As in E. nomax .

Structures: Pronotum with narrow lateral bead. Base of prosternum and neck of prosternal process with distinct ridge, rounded anteriorly. Blade of prosternal process lanceolate, relatively broad, slightly convex, with distinct bead and few setae laterally. Abdominal ventrite 6 truncate or slightly concave.

Male: Protarsomere 4 with large, thick, strongly curved anterolateral hook-like seta. Protarsomere 5 ventrally with anterior row of 20 and posterior row of seven relatively long setae ( Fig. 42D ). Abdominal ventrite 6 with 9-12 lateral striae on each side. Median lobe slender, with lateral setae apically; in lateral view, evenly curved to broadly pointed, short apex; in ventral view, apex slightly concave ( Fig. 42A, B ). Paramere very slightly concave on dorsal side, with long and dense subdistal and inconspicuous proximal setae ( Fig. 42C ).

Female: Without evident differences in external morphology from males, except for not modified protarsi and abdominal ventrite 6 without striae.

Affinities.

Exocellina warahulenensis sp. nov. can be distinguished by body size, form, colouration, inconspicuous dorsal punctation, simple male antenna, and shape and setation of its median lobe and paramere from the species co-occurring in the same area ( E. damantiensis , E. hintelmannae , and E. ullrichi (Balke, 1998)). In the dorsal colouration and surface sculpture, the new species is similar to E. larsoni but differs from it in shape and presence of setation of the median lobe. Exocelina warahulenensis sp. nov. is also very similar to E. nomax but is slightly larger and has darker colouration and longer median lobe, with lateral setae apically and shorter, broader apex in lateral view.

Distribution.

Papua New Guinea: Simbu and Eastern Highlands Provinces ( Fig. 45 ). The species is known only from Crater Mountain area.

Etymology.

The species is named after Wara Hulene Village where one of the paratype was collected. The name is an adjective in the nominative singular.

Figures

Figure 45. Map of the eastern part of New Guinea showing distribution of the species of the E. larsoni and takime groups.

Figures 35 - 39. Habitus and colouration 35 Exocelina larsoni (Balke, 1998) 36 E. nomax (J. Balfour-Browne, 1939) A holotype B specimen from Tapini 37 E. warahulenensis sp. nov. 38 E. mianminensis sp. nov. 39 E. takime (Balke, 1998).

Figures 41, 42. 41 Exocelina nomax (J. Balfour-Browne, 1939) 42 E. warahulenensis sp. nov. A median lobe in ventral view B median lobe in lateral view C paramere in external view D male protarsomeres 4 - 5 in ventral view.