Maechidius sougb sp. nov.

urn:lsid:zoobank.org:act: C8545020-E5E7-4EAA-B78C-B68FC1CB885D

Figs 85, 178, 255, 345, 417, 518, 715–717

Differential diagnosis

This is one of the largest Maechidius in the Papuan Region. It is distinguishable among all its Papuan congeners with an (almost) glabrous dorsum and bidentate protibiae primarily in the shape of the male genital organs, the 8-segmented antennae, the strongly protruding anterolateral angles of the male labroclypeus (which, in addition, is deeply emarginate anteriorly) in combination with rather delicate punctures on the pronotum and elytra. The most similar species, M. obiensis (Narakusumo & Balke, 2019) comb. nov., is generally smaller (body length under 7 mm), male metatibia thickened and somewhat curved on inner margin and with differently shaped aedeagus Maechidius pedarioides Arrow, 1941 (Raja Ampat Islands: Waigeo), has tridentate protibiae and stronger dorsal punctures, as well as less protruding anterolateral angles of the male labroclypeus.

Etymology

Named after Sougb, the local name of one of the main tribes and languages in the Anggi Lakes area of the Arfak Mountains. Sougb has the alternative names of Soug and Mantion, but is listed as Manikion by Simons & Fennig (2018). Noun in apposition.

Type material

Holotype

INDONESIA • ♂; “ INDONESIA E, W New Guinea, Doberai Peninsula, Arfak mts, Anggi Gigi Lake S env., Uper vill., 1°18’05”S, 133°54’24”E, 9-10 & 10-11.IX.2015, 2200 m, edge of primary mid montane rainforest, white light”; NME [tarsomeres 4–5 of right protarsus missing].

Paratype

INDONESIA • 1 ♂; same label as in holotype; DTC.

Description

MEASUREMENTS. Holotype, total body length 10.05 mm. Head 1.75 mm long, across eyes 2.07 mm wide. Pronotum 2.20 mm long, maximum width 3.10 mm. Elytral length 6.10 mm, maximum combined width 4.50 mm. Paratype 9.70 mm long.

Dorsum and venter uniformly dark castaneous with labroclypeus, mouthparts and legs somewhat paler reddish brown. Head transverse, glossy dorsally and ventrally, with large slightly prominent compound eyes occupying about half side of head. Male labroclypeus (Fig. 178) with deep and broad U-shaped emargination, its lateral margins sinuous in both dorsal and lateral views. Anterolateral angles large, acute angulate and raised up at angle of nearly 60–70° to axis of frons in lateral view. Anterior margin of labroclypeus smooth. Punctures of head irregularly circular, shallow, in part annular, larger in posterior part. Intervening spaces glossy, smaller than to as large as punctures. Pubescence yellowish, sparse, generally appressed and directed posteriad; seta rises from anterior margin of each puncture, surpassing length of corresponding puncture. Setae between compound eyes distinctly longer than those on forehead. Male antenna 8-segmented, antennal club 3-segmented. Scape large, with bulbous denticle-like predistal projection on upper side, provided with few long erect setae on its posterior and two very long on distal margin. Antennomere 2 strongly widened distally but not transverse. Pronotum transverse, glossy dorsally and laterally. Anterior margin of pronotum slightly sinuous with anterolateral angles (stronger) and mesal portion (slightly) protruding anteriad. Basal margin of pronotum very broadly rounded. Lateral margin of pronotum almost straight in anterior half, gradually widened towards median part, rounded in basal half and shortly emarginate just in front of posterolateral angles (Fig. 255). All along with well-defined crenulae which becomes protruding and denticle-like near prebasal emargination. Long erect seta present between each pair of lateral crenulae. Lateral margin of pronotum straight in lateral view. Pronotal punctures irregularly circular, rather small and shallow. Intervening spaces glossy, generally as large as to twice as large as punctures. Pronotal setae inconspicuous and short; seta rises from anterior margin of each puncture, slightly surpassing its length (pronotum looks glabrous). Hypomeron nearly straight, separated from prosternum by low slightly arched carina, with long setae on its anterolateral margin. Antennal pocket shallow. Scutellar shield narrowly triangular, rounded apically. Elytra slightly rounded laterally, maximum width across median third, glossy and flattened dorsally, with rounded humeri. Inconspicuous obtuse hump on each elytron near apex. No tracks of longitudinal carinae and no sutural carinae present. Each elytron between suture and humerus with 5 paired rows of delicate circular shallow punctures (some rows partly confused). Lateral sides of elytra more confusedly punctate (Fig. 345). Intervening spaces between punctures in rows larger than punctures, between rows about 3–4× as large as punctures. Elytral setae minute; seta rises from anterior margin of each puncture, reaches posterior margin or shortly surpassing its length. Lateral margin of elytra with moderately long suberect setae. Male pygidium (Fig. 518) and abdominal ventrites densely covered with large shallow annular punctures, each provided with suberect moderately long seta. Abdominal ventrites with no track of lateral longitudinal ridge. Legs long and slender, femora and tibiae covered with long erect setae arranged in 5 lines. Protibiae hardly sinuous on external margin. Protibiae with delicate carina on dorsal surface. Two large obtuse teeth on external margin of male protibia: distal one narrower, basal one broader and more obtuse (Fig. 417). Male protibial terminal spur absent. Tarsal claws with large pulvilli (in males only?). Male aedeagus as in Figs 715–717.

Sexual dimorphism

Female is unknown.

Ecology

Occurs in primary mid-montane rainforests at ~ 2200 m altitude. Possibly nocturnal.

Distribution

Hitherto only known from Arfak Mountains, Doberai Peninsula, western New Guinea.