Exocelina mondmillensis, 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 : 130-134

Taxon classification Animalia Coleoptera Dytiscidae

4. Exocelina mondmillensis sp. n. Figs 6, 11, 12

Type locality.

Papua New Guinea: Western Highlands Province, 5 km SE from Minj, Mondmill, 05°56.80'S, 144°39.90'E.

Type material.

Holotype: male "Papua New Guinea: Western Highlands, Mondmill, 5 Km SE Minj, small pools near creek, 1741 m, 12.vi.2006, 05.56.801S 144.39.898E, John (PNG 77)" (ZSM). Paratypes: Western Highlands: 53 males, 80 females with the same labels as the holotype (NARI, NHMW, ZSM). 81 males "Papua New Guinea: Western Highlands, Kurumul, 6 Km SW Kudjip, small stream, 1580 m, 13.vi.2006, 05.53.426S 144.36.600E, John (PNG 78)", one of them with an additional green label "DNA M.Balke 1339" (NARI, NHMW, ZSM). 69 males "Papua New Guinea: Western Highlands, Mt. Hagen town area, 1600m, 7.xii.1994 05.49.745S 144.22.357E Balke & Kinibel (PNG 131)" (NARI, NHMW, ZSM). 1 male, 1 female "Papua New Guinea: Western Highlands, Simbai, 1800-2000m, 26.ii.2007, 05.15.872S 144.32.717E, Kinibel (PNG 134)", the male with an additional green label "DNA M.Balke 3308" (ZSM). 9 males, 7 females "Papua New Guinea: Western Highlands, Simbai, Ineng River, 2000m, 27.ii.2007, 05.14.943S 144.32.818E, Kinibel (PNG 135)" (ZSM). 18 males, 21 females "Papua New Guinea: Western Highlands, Simbai, 2000m, 28.ii.2007, 05.15.174S 144.32.812E, Kinibel (PNG 136)" (NHMW, ZSM). 6 males, 1 female "Papua New Guinea: Western Highlands, Simbai, Fundum, 2000m, 1.iii.2007, 05.15.03S 144.30.867E, Kinibel (PNG 137)" (NHMW, ZSM). 23 males, 11 females "Papua New Guinea: Western Highlands, Simbai, 1800-2000m, 1.iii.2007, 05.14.276S 144.28.741E, Kinibel (PNG 138)" (NHMW, ZSM). 53 males "Papua New Guinea: Western Highlands, Simbai, Kairong River, 1850m, 2.iii.2007, 05.14.840S 144.28.457E, Kinibel (PNG 139)" (NHMW, ZSM). 4 males "Papua New Guinea: Western Highlands, Simbai - Jimi, 1500m, 2.iii.2007, 05.16.074S 144.27.886E, Kinibel (PNG 140)" (NHMW, ZSM). 1 male "Papua New Guinea: Western Highlands, Jimi, 1500m, 2.iii.2007, 05.16.335S 144.27.930E, Kinibel (PNG 141)" (ZSM). 18 males "Papua New Guinea: Western Highlands, Kundum, 1400m, 03.iii.2007, 05.16.096S 144.27.869E, Kinibel (PNG 142)" (NHMW, ZSM). 42 males "Papua New Guinea: Western Highlands, Lugup River, 1700m, 4.iii.2007, 05.17.237S 144.28.214E, Kinibel (PNG 143)" (NHMW, ZSM). 40 males "Papua New Guinea: Western Highlands, Gonzsidai-Sarup, 1700m, 4.iii.2007, 05.19.060S 144.28.671E, Kinibel (PNG 144)" one male with an additional green label "DNA M.Balke 3313" (NHMW, ZSM). 15 males "Papua New Guinea: Western Highlands, Above Sendiap, 1400m, 5.iii.2007, 05.19.774S 144.28.307E, Kinibel (PNG 145)" (NHMW, ZSM). 2 males "Papua New Guinea: Western Highlands, Jimi Valley, above Sendiap Station, 950m, 6.iii.2007, 05.20.587S 144.28.847E, Kinibel (PNG 147)" (ZSM). Enga: 17 males, 17 females "Papua New Guinea: Enga, nr Wabag, 1800m, 6.xii.2006, 05.30.124S 143.44.459E, Balke & Kinibel, (PNG 125)", one male with an additional green label "DNA M.Balke 1525" (NHMW, ZSM). 2 males "Papua New Guinea: Enga, nr Wapanamanda, 1700m, 6.xii.2006, 05.36.541S 143.52.559E, Balke & Kinibel (PNG 127)", one male with an additional green label "DNA M.Balke 1526" (ZSM). 8 males "Papua New Guinea: Enga, Wapanamanda, 1500m, 6.xii.2006, 05.38.105S 143.55.338E, Balke & Kinibel, (PNG 128)" (NHMW, ZSM). 12 males, 3 females "Papua New Guinea: Enga, Anji, 1900m, 6.xii.2006, 05.42.109S 143.55.635E, Balke & Kinibel, (PNG 129)" (NHMW, ZSM). Madang: 5 males, 14 females "Papua New Guinea: Madang, Keki, Adalbert Mts., 400m, 29.xi.2006, 04.43.058S 145.24.437E, Binatang Boys, (PNG 119)" (NHMW, ZSM).

Females of doubtful identity.

Western Highlands: 142 females "Papua New Guinea: Western Highlands, Kurumul, 6 Km SW Kudjip, small stream, 1580 m, 13.vi.2006, 05.53.426S 144.36.600E, John (PNG 78)" (NARI, NHMW, ZSM). These females are a mixture of three species: Exocelina mondmillensis sp. n., Exocelina edeltraudae (Shaverdo, Hendrich & Balke, 2012), and Exocelina damantiensis (Balke, 1998). 47 females "Papua New Guinea: Western Highlands, Mt. Hagen town area, 1600m, 7.xii.1994 05.49.745 S 144.22.357E Balke & Kinibel (PNG 131)" (NARI, ZSM). These females are a mixture of two species: Exocelina mondmillensis sp. n. and Exocelina edeltraudae . 50 females "Papua New Guinea: Western Highlands, Simbai, Kairong River, 1850m, 2.iii.2007, 05.14.840S 144.28.457E, Kinibel (PNG 139)" (NARI, ZSM). 10 females "Papua New Guinea: Western Highlands, Simbai - Jimi, 1500m, 2.iii.2007, 05.1.074S 144.27.886E, Kinibel (PNG 140)" (ZSM). 7 females "Papua New Guinea: Western Highlands, Jimi, 1500m, 2.iii.2007, 05.16.335S 144.27.930E, Kinibel (PNG 141)" (ZSM). 33 females "Papua New Guinea: Western Highlands, Kundum, 1400m, 03.iii.2007, 05.16.096S 144.27.869E, Kinibel (PNG 142)" (ZSM). These females are a mixture of two species: Exocelina mondmillensis sp. n. and Exocelina jimiensis Shaverdo & Balke, 2014. 26 females "Papua New Guinea: Western Highlands, Gonzsidai-Sarup, 1700m, 4.iii.2007, 05.19.060S 144.28.671E, Kinibel (PNG 144)" (ZSM). These females are a mixture of two species: Exocelina mondmillensis sp. n. and Exocelina edeltraudae . 34 females "Papua New Guinea: Western Highlands, Lugup River, 1700m, 4.iii.2007, 05.17.237S 144.28.214E, Kinibel (PNG 143)" (NHMW, ZSM). 9 females "Papua New Guinea: Western Highlands, Above Sendiap, 1400m, 5.iii.2007, 05.19.774S 144.28.307E, Kinibel (PNG 145)" (ZSM). 9 females "Papua New Guinea: Western Highlands, Jimi Valley, above Sendiap Station, 950m, 6.iii.2007, 05.20.587S 144.28.847E, Kinibel (PNG 147) (ZSM). These females are a mixture of two species: Exocelina mondmillensis sp. n. and Exocelina madangensis (Balke, 2001). Enga: 10 females "Papua New Guinea: Enga, Wapanamanda, 1500m, 6.xii.2006, 05.38.105S 143.55.338E, Balke & Kinibel, (PNG 128)" (ZSM). These females are a mixture of two species: Exocelina mondmillensis sp. n. and Exocelina madangensis (Balke, 2001).

Diagnosis.

Beetle medium-sized, brown to piceous, with reddish head and pronotal sides, shiny; median lobe with slightly curved downwards apex but thin in lateral view and ventral sclerite with two unequal apices (left one long, narrow and curved and right one short, broad and more or less rounded). The species is similar to Exocelina marinae and Exocelina pseudomarinae sp. n. in shape of the ventral sclerite of median lobe, but distinctly differs from them in having fine, inconspicuous punctation and weak microreticulation on the dorsal surface and a thin tip of the median lobe. From Exocelina broschii and Exocelina hintelmannae , it can be distinguished by the shape of the median lobe (thin apex) and its ventral sclerite (very long left lobe), and from the former also by finer elytral punctation.

Description.

Size and shape: Beetle medium-sized (TL-H 3.5-4.1 mm, TL 3.9-4.5 mm, MW 1.8-2.2 mm), with oblong-oval habitus, broadest at elytral middle. Coloration: Head reddish brown to piceous, usually darker medially and posterior to eyes, sometimes almost uniform; pronotum with brown to piceous medially and reddish brown to brown sides; elytra brown to piceous, usually with narrow reddish sutural lines; head appendages and legs yellowish to reddish, legs distally darker, especially metathoracic legs (Fig. 6). Teneral specimen with coloration paler.

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 much sparser and finer punctation than head. Elytra with very sparse and fine punctation, almost invisible. Pronotum and elytra with weakly impressed microreticulation, dorsal surface shiny. Head with microreticulation stronger. Metaventrite and metacoxae distinctly microreticulate, metacoxal plates with longitudinal strioles and transverse wrinkles. Abdominal ventrites with distinct microreticulation, strioles, and very fine and sparse punctation.

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. 6). Protarsomere 4 with large, thick, strongly curved anterolateral hook-like seta. Protarsomere 5 ventrally with anterior row of 18 and posterior row of 4 short setae (Fig. 11A). Median lobe with thin apex, slightly curved in lateral view and pointed in ventral view. Its ventral sclerite with two unequal apices (left one long, narrow and curved and right one short, broad and more or less rounded). Paramere with subdistal setae denser and thicker than proximal setae (Fig. 11 B–D). Abdominal ventrite 6 with 4-7 lateral striae on each side.

Holotype: TL-H 4.05 mm, TL 4.45 mm, MW 2.15 mm.

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

Variability: Beetles vary mainly in shape of the ventral sclerite of the median lobe as shown in Fig. 12.

Distribution.

Papua New Guinea: Western Highlands, Enga, and Madang Provinces (Fig. 14).

Etymology.

The name refers to Mondmill, the type locality, where the species was found in great numbers. The name is an adjective in the nominative singular.