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 brocki sp. nov. urn:lsid:zoobank.org:act: 39227DD9-2D93-4AF8-BFF8-050C6B0EF97B Figs 29 , 109–110 , 206 , 296 , 368, 462, 539, 601–603 Differential diagnosis This species most closely resembles Maechidius hirtipes Arrow, 1941 (Papuan Peninsula, East New Guinea ) and M. subcostatus Heller, 1895 (Finisterre Mountains, East New Guinea ), but readily differs from both primarily in the shape of the male genital organs.Additionally, in M. hirtipes the lateral margin of the pronotum is denticulate (tuberculate in M. brocki sp. nov. ) and slightly emarginate (strongly emarginate in M. brocki sp. nov. ) and the basal metatarsomere has a brush of very long, dense sinuous setae on the inner margin (absent in M. brocki sp. nov. ). Etymology Patronymic. This species is dedicated to Paul Brock (Brockenhurst, United Kingdom ), a famous phasmid expert, experienced macrophotographer, respected colleague and my friend. Type material Holotype PAPUA NEW GUINEA • ♂ ; “ ♂ [p] // PAPUA : Mafulu. 4,000 ft. xii.1933 . L.E.Cheesman. B.M.1933- 321. [p]”; BMNH . Paratypes ( 8 specimens ) PAPUA NEW GUINEA • 1 ♂♂ , 6 ♀♀ ; same labels as for holotype but without sex label; BMNH • 1 ♀ ; “ PAPUA : Mafulu . 4,000 ft. xii.1933 . L.E.Cheesman. B.M.1933-321. [p]// Maechidius subcostatus , Hell. Determined from description. G.J.A. [p]”; BMNH . Description MEASUREMENTS. Holotype , total body length 8.25 mm . Head 1.55 mm long, across eyes 1.85 mm wide. Pronotum 1.70 mm long, maximum width 2.85 mm . Elytral length 5.00 mm, maximum combined width 3.90 mm . The largest paratype ( ♀ ) 9.25 mm long. Dorsum and venter uniformly black-brown with castaneous labroclypeus, mouthparts, and legs. Head transverse, glossy dorsally and ventrally, flattened between eyes and vaguely impressed on labroclypeus anterior to each compound eye. Compound eye large, occupying over about half side of head. Male labroclypeus ( Fig. 109 ) broadly emarginate on anterior margin, its lateral margins strongly sinuous in both dorsal and lateral views, anterolateral angles protruding, bent up at ~90° to frons in lateral view. Female labroclypeus ( Fig. 110 ) shallower emarginate on anterior margin, with broader rounded anterolateral angles. Upper- and underside of labroclypeus with sparse long setae along anterior and lateral margins. Canthus sinuous in dorsal view. Anterior and lateral margins of labroclypeus smooth. Head dorsal punctures circular to irregularly hexagonal, large and moderately deep. Intervening spaces glossy, much smaller than punctures, in part wrinkled. Head setae suberect, generally surpassing length of corresponding punctures. Few much longer suberect setae along inner margin 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 sinuous with anterolateral angles (stronger) and mesal portion (slightly) protruding anteriad. Basal margin of pronotum broadly rounded. Lateral margin gradually widens towards postmedium, very deeply emarginate prebasally ( Fig. 206 ). Crenulae of lateral margin long and large except for smooth emargination area; suberect seta present between every two crenulae. Lateral margin of pronotum sinuous in lateral view. Pronotal punctures irregularly hexagonal, dense and moderately deep, variably large. Intervening spaces glossy and glabrous, much smaller than punctures, in part wrinkled. Appressed seta rises from anterior margin of each puncture, not surpassing length of corresponding puncture. Hypomeron separated from prosternum by moderately high sinuous carina strongly acutely dentate medially, with long setae on anterolateral margin. Antennal pocket moderately deep. Median anterior process of prosternum long brushy setose, short, flange-like rised. Scutellar shield narrowly rounded apically. Elytra slightly widened in posterior half, maximum width post midlength, opaque dorsally, with distinct humeri. Vague tracks of 2–3 inconspicuous, very flat longitudinal carinae on disc of each elytron. Elytral punctures linear (long and narrow), incisionshaped, moderately deep and dense ( Fig. 296 ). Intervening spaces covered with microscopical velvety pubescence, larger than incisions. Setation inconspicuous, suberect; seta rises from anterior margin of each incision, not or hardly surpassing its length. Male pygidium flat dorsally, with large shallow annular punctures ( Fig. 462 ). Intervening spaces generally smaller than punctures, in part microreticulate. Setae of pygidium inconspicuous, suberect, about length of corresponding punctures. Male protibia slightly arched on external margin, with three obtuse distal teeth on external margin (Fig. 368). Male protibial terminal spur short, thick and pointed apically, female one longer, straight and acute. All tarsal claws with large pulvilli. Spiculum gastrale as in Fig. 539. Male aedeagus as in Figs 601–603 . Sexual dimorphism Female lamellae of antennal club shorter; anterior margin of labroclypeus comparatively less deeply emarginate. Ecology Occurs at about 1220 m altitude. Distribution Hitherto only known from the Papuan Peninsula of New Guinea .