Exocelina morobensis 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

4. Exocelina morobensis Shaverdo & Balke sp. nov. Figs 4 , 10

Exocelina undescribed sp. MB1313: Toussaint et al. 2014: supplementary figs 1-4, tab. 2; Toussaint et al. 2015: supplementary figs S1, S2, tab. S3, and information S5, S6.

Exocelina undescribed sp. MB3840: 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: Morobe Province, Garaina, 07°51'03"S, 147°07'01"E, 720 m a.s.l.

Type material.

Holotype: male "Papua New Guinea Garaina, 720m, vi.2008, 07.51.032S 147.07.007E Ibalim & Sosanika PNG216" (ZSM). Paratypes: Morobe: 72 males, 83 females with the same label as the holotype (NHMW, ZSM). 64 males, 69 females "Papua New Guinea: Morobe, Garaina, 800m, vi.2008, 07.53.091S 147.07.915E Ibalim & Sosanika PNG217" (NHMW, ZSM). 2 males, 4 females "Papua New Guinea Garaina, 800m, vi.2008, 07.53.091S 147.07.915E Ibalim & Sosanika PNG217" (ZSM). 27 males, 18 females "Papua New Guinea: Morobe, Garaina, 770m, vi.2008, 07 52.516S 147.10.427E Ibalim & Sosanika (PNG219)" (NHMW, ZSM). 26 males, 25 females "Papua New Guinea Morobe, Garaina, 800m, 27.vi.2009, (PNG220) 7.52.669S 147.07.196E Ibalim & Sosanika" (NHMW, ZSM). 11 males, 11 females "Papua New Guinea: Morobe, Garaina, 770m, 25.vi.2008, 07 50.859S 147.08.614E Ibalim & Sosanika (PNG222)" (NHMW, ZSM). 2 males, 1 female "Papua New Guinea Morobe, Garaina, 670m, 23vi2008 (PNG223) 7.52.431S 147.10.267E Ibalim & Sosanika (PNG223)" (ZSM). 9 males, 6 females "Papua New Guinea: Morobe, Garaina, 820m, 24.vi.2008, 07.52.287S 147.06.297E Ibalim & Sosanika, (PNG224)" (ZSM). 15 males, 14 females "Papua New Guinea: Morobe, Huon Pen., rd to Kwapsanek, 250m, 31.iii.2006, 06.30.270S (PNG 24) 146.59.581E, Balke & Sagata" (NHMW, ZSM). 4 males, 5 female "Papua New Guinea: Morobe, Huon Pen., rd to Kwapsanek, 250m, 31.iii.2006, 06.30.270S 146.59.581E, Balke & Sagata (PNG 24A)" (ZSM). 2 males, 1 female "Papua New Guinea: Morobe, Huon Pen., rd to Kwapsanek, 460m, 31.iii.2006, 06.32.736S 146.59.616E, Balke & Sagata (PNG 26)", one male with an additional label "DNA M.Balke 1313" (ZSM). 73 males, 56 females "Papua New Guinea: Morobe, Herzog Mts., Bundun, 700-800m, 2.iv.1994, 06.51.598S 146.37.07E, Balke & Sagata (PNG 27)", one male with an additional green label "DNA M.Balke 1312" (NHMW, ZSM). 1 male "NEW GUINEA: Morobe Dist., Lae-Bulobo Rd., 28.xii.1964.", "Stn. No. 123.", "M.E. Bacchus. B.M. 1965-120" (BMNH). 1 male, 2 females "Papua New Guinea: Morobe, Sattelberg, Zige River, 970m, 20.x.2009, 6 29.233S 147.46.482E, Inaho (11) (PNG211)", the male with an additional green label "DNA M.Balke 3828" (ZSM). 2 males, 1 female "Papua New Guinea: Morobe, Sattelberg, Zige River, ca 700m, x.2009, 6 29.233S 147.46.482E, Inaho (12a) (PNG212)", one of the males with an additional green label "DNA M.Balke 3823" (ZSM).

Description.

Body size and form: Beetle medium-sized, rarely small: TL-H 3.3-4.1 mm, TL 3.6-4.5 mm, MW 1.75-2.1 mm (holotype: TL-H 3.9 mm, TL 4.35 mm, MW 2.05 mm), with oblong-oval habitus.

Colouration: Brown to dark brown, usually with reddish pronotum and head. Head reddish to brown, sometimes darker posterior eyes; pronotum reddish to brown, often broader or narrower darker area on disc; elytra brown to dark brown, sometimes with reddish sutural lines; head appendages and legs proximally reddish, legs distally darker, reddish brown to brown ( Fig. 4 ). Teneral specimen paler.

Surface sculpture: Shiny dorsally, with fine, sparse punctation and weakly impressed microreticulation. Head with relatively fine and sparse punctation (spaces between punctures 2-3 times size of punctures); diameter of punctures almost equal to or smaller than diameter of cells of microreticulation. Pronotum and elytra with much finer and sparser punctation than on head, often inconspicuous on elytra. Pronotum and elytra with weakly impressed microreticulation. Head with microreticulation slightly stronger. Metaventrite, metacoxae, and abdominal ventrites distinctly microreticulate. Metacoxal plates with longitudinal strioles and weak transverse wrinkles; abdominal ventrites with strioles. Venter with extremely inconspicuous punctation, more evident on metacoxal plates and two last abdominal ventrites.

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 narrow, slightly convex, with distinct bead and few setae laterally. Abdominal ventrite 6 very slightly truncate.

Male: Protarsomere 4 with with large, thick, strongly curved anterolateral hook-like seta. Protarsomere 5 ventrally with anterior band of ca. 50 and posterior row of seven relatively long setae ( Fig. 10D ). Abdominal ventrite 6 with 5-7 lateral striae on each side. Median lobe evenly curved, rather thin, lateral margins thickened proximally; in lateral view, apex elongate, slightly thickened and rounded; in ventral view, median lobe broad proximally and distinctly narrowed in distal half, apex bluntly pointed ( Fig. 10A, B ). Paramere slightly concave on dorsal side, its subdistal part with dense, strong setae, proximal setae weaker, less distinct ( Fig. 10C ).

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

Affinities.

From the species co-occurring in the same area ( E. brahminensis Shaverdo, Hendrich & Balke, 2012, E. damantiensis , and E. garaina Shaverdo & Balke, 2016), E. morobensis sp. nov. can be distinguished by its size, colouration, narrow pronotal bead, and shape and setation of the median lobe and paramere.

Distribution.

Papua New Guinea: Morobe Province ( Fig. 11 ).

Etymology.

The species is named after Morobe Province, the only province of PNG where the species has been found. The name is an adjective in the nominative singular.

Figures

Figure 10. Exocelina morobensis 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.

Figure 11. Map of the eastern part of New Guinea showing distribution of the species of the monotypic groups.

Figures 1 - 4. Habitus and colouration 1 Exocelina aipomek (Balke, 1998) 2 E. mekilensis sp. nov. 3 E. koroba sp. nov. 4 E. morobensis sp. nov.