Exocelina garana Shaverdo & Balke

Shaverdo, Helena, Sagata, Katayo & Balke, Michael, 2016, Taxonomic revision of New Guinea diving beetles of the Exocelinadanae group, with the description of ten new species (Coleoptera, Dytiscidae, Copelatinae), ZooKeys 619, pp. 45-102 : 64-66

Taxon classification Animalia Coleoptera Dytiscidae

8. Exocelina garana Shaverdo & Balke sp. n. Figs 21, 37

Exocelina undescribed sp. MB3876: Toussaint et al. 2014: supplementary figs 1-4, tab. 2.

Type locality.

Papua New Guinea: Morobe Province, Garaina, 07°45'05.8"S; 147°08'57.0"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", "DNA M.Balke 3876", (ZSM). Paratype: 1 female with the same geographical label as the holotype (ZSM).

Diagnosis.

Beetle medium-sized, dark brown to piceous; dorsal punctation and microreticulation fine; pronotum with lateral bead; male antennomeres simple; male protarsomere 4 with large, thick, strongly curved anterolateral hook-like seta; median lobe slightly broadened and almost rounded distally, with apex weakly concave in ventral view and evenly curved in lateral view, with numerous fine laterodistal setae; paramere without notch on dorsal side; subdistal setae dense, proximal inconspicuous. This species is very similar to Exocelina damantiensis but differs from it in the shape of the median lobe: almost rounded distally in ventral view and evenly tapering in lateral view; its apex not curved in lateral view, as well in less numerous subdistal setae of the paramere. These morphological characters and the fact that this species is phylogenetically quite isolated from Exocelina damantiensis ( Toussaint et al. 2014) support its delimitation.

Description.

Size and shape: Beetle medium-sized (TL-H 4.25-4.5 mm, TL 4.75-5.0 mm, MW 2.2-2.35 mm), with oblong-oval habitus, broadest at elytral middle. Coloration: Male distinctly darker than female. Head reddish-brown to almost piceous; pronotum brown to piceous, with paler (reddish to dark brown) sides and darker (piceous) disc; elytron uniformly piceous or dark brown with reddish sutural line; head appendages yellowish-red, legs reddish-brown (Fig. 37).

Surface sculpture: Head with dense punctation (spaces between punctures 1-3 times size of punctures), evidently finer and sparser anteriorly; diameter of punctures smaller than diameter of cells of microreticulation. Pronotum with finer, sparser, and more evenly distributed punctation than on head. Elytra with very sparse and fine punctation, almost invisible. Pronotum and elytra with weakly impressed microreticulation, dorsal surface, thus, shiny. Head with microreticulation stronger. Metaventrite and metacoxa distinctly microreticulate, metacoxal plates with longitudinal strioles and transverse wrinkles. Abdominal sternites with distinct microreticulation, strioles, and fine sparse punctation, coarser and denser on two last abdominal sternites.

Structures: Pronotum with distinct lateral bead. Base of prosternum and neck of prosternal process with distinct ridge, smooth and not rounded anteriorly, without anterolateral extensions. Blade of prosternal process lanceolate, relatively narrow, convex, with distinct bead and few setae; neck and blade of prosternal process evenly jointed. Abdominal ventrite 6 slightly truncate apically.

Male: Antenna simple. Protarsomere 4 with large, thick, strongly curved anterolateral hook-like seta. Protarsomere 5 ventrally with anterior band of ca. 50 and posterior row of 11 relatively long setae (Fig. 21B). Abdominal ventrite 6 with 4 lateral strioles on each side. Median lobe slightly broadened and almost rounded distally, with apex weakly concave in ventral view and evenly tapering in lateral view; on both lateral sides with fine setae situated on distal part of median lobe (Fig. 21 B–C). Paramere without notch on dorsal side and with dense setae on subdistal part; proximal setae more numerous but inconspicuous (Fig. 21D).

Holotype: TL-H 4.25 mm, TL 4.75 mm, MW 2.2 mm; dorsally piceous.

Female: Pro- and mesotarsi not modified; abdominal ventrite 6 without striae; dorsal coloration paler than in male: dark brown with reddish brown head, pronotal sides and sutural lines on elytra; dorsal punctation slightly stronger.

Distribution.

Papua New Guinea: Morobe Province. This species is known only from the type locality area (Fig. 40).

Etymology.

The species is named after Garaina Village. The name is a noun in the nominative singular standing in apposition.