Exocelina pseudomarinae, Shaverdo, Helena, Sagata, Katayo & Balke, Michael, 2016

Shaverdo, Helena, Sagata, Katayo & Balke, Michael, 2016, Description of two new species of the Exocelinabroschii-group from Papua New Guinea, with revision and key to all representatives of this species group (Coleoptera, Dytiscidae, Copelatinae), ZooKeys 577, pp. 125-148 : 134-135

Taxon classification Animalia Coleoptera Dytiscidae

5. Exocelina pseudomarinae sp. n. Figs 7, 13

Exocelina undescribed sp. MB1287: Toussaint et al. 2014: Supplementary figs 1-4, tab. 2.

Type locality.

Papua New Guinea: Hela Province, Tari, 05°50.38'S, 142°55.90'E.

Type material.

Holotype: male "Papua New Guinea: Southern Highlands, Tari (trickle in gardenland), 1700m, 12.v.2006, 05.50.383S 142.55.901E, Balke (PNG 58)", "DNA M.Balke 1287" [green] (ZSM). Paratypes: 2 males, 1 female with the same labels as the holotype (NHMW, ZSM).

Diagnosis.

Beetle medium-sized, brown to dark brown, with reddish head and pronotal sides, submatt; median lobe with apex strongly curved downwards in lateral view and ventral sclerite with two unequal apices (left one long, narrow and curved apically and right one short, broad and more or less strait). The species is similar to Exocelina marinae Shaverdo, Sagata & Balke, 2005 from which distinctly differs in larger size, sparser and finer punctation and weaker microreticulation of the dorsal surface, and strongly curved apex of the median lobe, which is similar to that of Exocelina hintelmannae Shaverdo, Sagata & Balke, 2005. The specimen of Exocelina marinae from Tari-Koroba, though large in size and with the same distribution, has a distinctly stronger sculpture on the dorsal surface and a median lobe with only a slightly curved apex in lateral view and a narrower right lobe of the ventral sclerite. Therefore, it can be easily distinguished from Exocelina pseudomarinae sp. n.

Description.

Size and shape: Beetle medium-sized (TL-H 3.55-4.05 mm, TL 3.85-4.4 mm, MW 1.9-2.1 mm), with oblong-oval habitus, broadest at elytral middle. Coloration: Head reddish brown, brown to dark brown medially and posterior to eyes; pronotum with brown to dark brown medially (to piceous - narrow part on disc) and reddish brown sides; elytra brown to dark brown, sometimes with narrow reddish brown sutural lines; head appendages yellowish, legs yellowish to reddish, distally darker, especially metathoracic legs (Fig. 7). Teneral specimen with coloration slightly paler.

Surface sculpture: Head with very dense punctation (spaces between punctures 1-2 times size of punctures), evidently finer and sparser anteriorly; diameter of punctures smaller than diameter of cells of microreticulation or equal to it. Pronotum and elytra with punctation sparser and finer than on head, but very distinct. Pronotum and elytra with distinct microreticulation, dorsal surface submatt. Head with microreticulation stronger. Metaventrite and metacoxae distinctly microreticulate, metacoxal plates with longitudinal strioles and transverse wrinkles. Abdominal ventrites with distinct microreticulation, strioles, and sparse punctation, coarser on two last abdominal ventrites.

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

Male: Antenna simple (Fig. 7). Protarsomere 4 with large, thick, strongly curved anterolateral hook-like seta. Protarsomere 5 ventrally with anterior row of 20 and posterior row of 7 short setae (Fig. 13A). Median lobe with strongly curved apex in lateral view and more or less rounded in ventral view. Its ventral sclerite with two unequal apices (left one long, narrow and curved apically and right one short, broad and more or less strait). Paramere with subdistal setae denser and thicker than proximal setae (Fig. 13 B–D). Abdominal ventrite 6 with 6-8 lateral striae on each side.

Holotype: TL-H 4.05 mm, TL 4.4 mm, MW 2.1 mm.

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

Distribution.

Papua New Guinea: Hela Province. This species is known only from the type locality (Fig. 14).

Etymology.

The name points to similarity of the new species to Exocelina marinae . The name is a noun in the nominative singular standing in apposition.