Scopaeus arfakmontium, Frisch & Mainda, 2022

Frisch, Johannes & Mainda, Tobias, 2022, The Scopaeus kokodanus species group (Coleoptera: Staphylinidae: Paederinae) from New Guinea and the Solomon Islands, with description of three new species, Soil Organisms 94 (3), pp. 139-147 : 142-143

Scopaeus arfakmontium spec. nov.

( Figs 2 , 5 , 8–10 , 17, 18 )

Type specimens: Holotype ♂, Indonesia, West Papua: Arfak Mts , 500 m, 08.02.2011, leg. Watanabe ( TWCF) . Paratypes: 4 ♂, same data as holotype ( MFNB, TWCF) .

Diagnosis: Body shape and coloring as in Fig. 2 . Total body length 4.7 – 5.0 mm; forebody length 2.7 – 2.8 mm. Head pyriform, 1.13 – 1.15 (Ø 1.14) times as long as wide, across eyes 1.34 – 1.42 (Ø 1.36) times as wide as across tempora at half of their length from eyes to neck constriction. Eyes 0.5 – 0.55 (Ø 0.52) times as long as tempora. Elytra about 1.14 times as long as pronotum. Penultimate segment of antenna about 1.3 times as long as wide. Tibia of mesothoracic leg 9.2 – 11.2 (Ø 9.7) times as long as wide. Body black except for dark brown maxillary palpi with light brown apex of last segment, dark brown legs with medium brown tarsi, and antennae becoming evenly lighter from dark brown proximal segments towards light brown apical segments.

Male: Aedeagus ( Fig. 5 ) about 0.9 mm long; apical lobes parallel in lateral view ( Fig. 8 ), in ventral and dorsal view ( Figs 9, 10 ) convex laterally; lateral lobes notably longer than wide ( Figs 9, 10 ); dorsal lobe triangular in dorsal view with subacute apex ( Fig. 10 ). Asetose median depression of abdominal sternite VII ( Fig. 17 ) with parallel lateral margins. Abdominal sternite VIII ( Fig. 18 ) with median lobe of posterior margin notably longer than lateroposterior angles; end of median lobe notably emarginate.

Distribution: Scopaeus arfakmontium is hitherto known only from the type locality in the Arfak Mountains in the east of the Bird’s Head Peninsula, West Papua.

Comparative notes: Among the related species treated here, Scopaeus arfakmontium ( Fig. 2 ) is readily distinguishable from S. kokodanus ( Fig. 1 ) by the entirely black body without a light posterior margin of the elytra and the more elongate distal antennal segments. It differs from both S. balkei ( Fig. 3 ) and S. potamides ( Fig. 4 ) by larger body size, the pyriform head, the larger aedeagus ( Fig. 5 ) with elongate lateral lobes and the shape of the apical lobes, which are convexely widened laterally and parallel in lateral view ( Figs 8–10 ), and by the posterior margin of abdominal sternite VIII with the median lobe longer than the lateroposterior angles ( Fig. 18 ) and without four distinct, black macrosetae (see Figs 20, 22 ).

Etymology: The epithet ‘ arfakmontium ’ (latin, noun, genitive: ‘of the Arfak Mountains’) refers to the type locality of the new species.

Figures

Figures 1–4. Habitus of Scopaeus kokodanus, Papua New Guinea, Morobe, Waritaian (1), S. arfakmontium, paratype, Indonesia, West Papua,Arfak Mts (2), S. balkei, paratype, Indonesia, Papua, Cyclops Mts (3), S. potamides, paratype, Solomon Islands, Kolombangara (4).

Figures 5–7. Aedeagus (in lateral view) of Scopaeus arfakmontium, holotype, Indonesia, West Papua, Arfak Mts (5), S. balkei, holotype, Indonesia, Papua, Cyclops Mts (6), S. potamides, holotype, Solomon Islands, Kolombangara (7). Abbreviations: dl – distal lobes, pb – phallobase.

Figures 8–16. Apical portion of aedeagus in lateral (8, 11, 14), ventral (9, 12, 15), dorsal view (10, 13, 16) of Scopaeus arfakmontium, holotype, Indonesia, West Papua, Arfak Mts (8–10), S. balkei, holotype, Indonesia, Papua, Cyclops Mts (11–13), S. potamides, holotype, Solomon Islands, Kolombangara (14–16). Abbreviations: al – apical lobes, dl – dorsal lobe, f – flagellum, ll – lateral lobe.

Figures 17–24. Abdominal sternite VII (17, 19, 21) and abdominal sternite VIII (18, 20, 22) of Scopaeus arfakmontium, holotype, Indonesia, West Papua,Arfak Mts (17, 18), S. balkei, holotype, Indonesia, Papua, Cyclops Mts (19, 20), S. potamides, paratype, Solomon Islands, Kolombangara (21, 22), S. kokodanus (23). Figs 23, 24: sperm pumps of (23) S. kokodanus, Papua New Guinea, Morobe, (24) S. balkei, paratype, Indonesia, Papua, Cyclops Mts.