A revision of the Maechidiini Burmeister, 1855 (Coleoptera: Scarabaeidae: Melolonthinae) from the Indo-Australian transition zone, and the first record of the tribe west of Wallace’s Line Author Telnov, Dmitry text European Journal of Taxonomy 2020 2020-10-19 721 1 210 journal article 9693 10.5852/ejt.2020.721.1127 0cd61b23-1089-4c1b-bfc0-487887abad84 4122118 89E62EF8-2E45-4C59-94B7-6A5603E8939B Maechidius hamatus sp. nov. urn:lsid:zoobank.org:act: DCA112DF-06B6-4767-8991-20D54ED810E7 Figs 39 , 121 , 215 , 305 , 378–379, 431–432, 472, 544, 617–619 Differential diagnosis This is the second species of the dani informal species-group, see the diagnosis of Maechidius dani sp. nov. above. Etymology The specific name is derived from the Latin ‘ hamatus ’ (‘hooked’), referring to the curved denticles of male protarsomeres 1 and 2. Type material Holotype INDONESIA • ♂ ; “ INDONESIA , Papua : Jayawijaya Distr. : Baliem valley , 10km NE of Wamena , forest above “Baliem valley resort”, 04°03.6’S , 139°01.9’E , 2050 m ; 2-3.ii.2015 J.Hájek & JŠumpich leg. // coll. general National Museum Prague, Czech Republic”; NMPC . Paratypes ( 4 specimens ) INDONESIA • 3 ♂♂ ; same labels as for holotype; NMPC • 1 ♂ ; same labels as for holotype; DTC . Description MEASUREMENTS. Holotype , total body length 7.10 mm . Head 1.30 mm long, across eyes 1.63 mm wide. Pronotum 1.60 mm long, maximum width 2.67 mm . Elytral length 4.20 mm , maximum combined width 3.30 mm . Paratypes 7.30–7.90 mm long. Dorsum and venter uniformly black-brown with reddish brown labroclypeus, mouthparts, antennae, legs and most of venter. Head transverse, glossy dorsally and ventrally, somewhat convex between eyes and vague impressed on labroclypeus anterior to each compound eye. Compound eye large, occupying about half head side. Male labroclypeus ( Fig. 121 ) very shallowly emarginate anteriorly, its lateral margins curved in dorsal and sinuous in lateral view, anterolateral angles weakly protruding, obtuse and rounded in dorsal view, bent up at ~80–90° to frons in lateral view. Upper- and underside of labroclypeus with sparse moderately long setae along anterior and lateral margins. Canthus nearly straight in dorsal view. Anterior and lateral margins of labroclypeus smooth. Dorsal punctures circular to ovoid, small and shallow on labroclypeus, larger and moderately deep on frons. Intervening spaces glossy and glabrous, generally larger than punctures. Inconspicuous very short appressed seta rises from anterior margin of each puncture, surpassing or not length of corresponding puncture. Few much longer suberect setae along interior surface of either eye. Antenna 9-segmented, club 3-lamellate. Scape large, with bulbous predistal projection on dorsal side, provided with two very long setae near distal margin. Antennomere 2 trapezoid, transverse. Pronotum glossy dorsally and laterally. Anterior margin of pronotum slightly sinuous with anterolateral angles protruding anteriad and mesal portion nearly straight. Basal margin of pronotum slightly sinuous. Lateral margin of pronotum broadly rounded ( Fig. 215 ). Crenulae of lateral margin poorly defined and rather short; short suberect and posteriad directed seta present between every two crenulae. Lateral margin of pronotum nearly straight in lateral view. Punctures of pronotal disc ovoid, moderately deep, variably large; inner margin with delicate membrane in part covered by microscopical velvety pubescence and partly to completely encircles puncture. Intervening spaces glossy and glabrous, variably large but generally as large as to larger than punctures. Setation as on head but setae not surpassing length of corresponding punctures. Lateral and basal margins, antero- and posterolateral angles partly covered with microscopical velvety pubescence. Hypomeron slightly curved and very long setose on anterior margin which is flange-like protruding. Antennal pocket deep. Median anterior process of prosternum long brushy setose, broad, strongly raised. Scutellar shield rounded apically. Elytra slightly widened in posterior half, maximum width across midlength, glossy dorsally, with distinct humeri. Vague tracks of two inconspicuous, very flat glabrous longitudinal carinae on disc of each elytron. Punctures of elytral disc ovoid, somewhat denser than those on pronotum, irregular but becoming arranged in irregular rows in apical third ( Fig. 305 ). Inner margin of each puncture with delicate membrane, in some punctures in part covered by microscopical velvety pubescence and partly encircles the puncture. Setation inconspicuous and short, appressed; each seta rises from anterior margin of corresponding puncture, not or hardly surpassing length of puncture. Epipleuron all along with very short appressed setae. Male pygidium flattened dorsally, sparsely circular to oblongo-punctate, opaque microreticulate on intervening spaces, with sparse moderately long suberect clavate setae in distal part and short appressed ones not surpassing length of corresponding punctures in anterior part of pygidium ( Fig. 472 ). Venter covered with sparse small shallow punctures, each provided with very short seta. Third visible abdominal sternite with small median triangular hump on posterior margin ( Figs 431–432 ). Legs long and slender. Male protibia nearly straight on external margin (slightly curved), delicately crenulate in basal two-thirds, with almost complete obtuse dorsal carina. Two obtuse distal teeth on male protibia, distal more acute than inconspicuous broad basal one (Fig. 378). Protibial terminal spur nearly straight, acute. Male metatibial terminal spurs paired, long, acute, lower (longer) one slightly curved. Underside of male protarsomeres 1 and 2 each with large acute and apically slightly hooked distal denticle (Fig. 379). Male tarsal claws with large pulvilli. Spiculum gastrale as in Fig. 544. Male aedeagus as in Figs 617–619 . Sexual dimorphism Female is unknown. Ecology Occurs in mid-montane rainforests at about 2050 m altitude. Distribution Hitherto only known from the Baliem Valley, Central Cordillera of New Guinea .