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 vicinus Heller, 1914 Figs 93 , 189–190 , 262 , 284 , 353 , 425 , 529–530, 736–738 Type material Lectotype [herewith designated] COUNTRY UNKNOWN ( Island of New Guinea ) • ♀ ; “ Gehr. W. Müller Vermächt. 1909 [p, blue label]// Typus ! [p] vicinus Heller [h, red label] // N. Guinea [p, blue label] // Staatl. Museum für Tierkunde,Dresden [p]”; SNSD . Paralectotype COUNTRY UNKNOWN ( Island of New Guinea ) • 1 ♀ ; “N. Guinea [p, blue label]// Gehr. W. Müller Vermächt. 1909 [p, blue label]// Staatl. Museum für Tierkunde Dresden [p]”; SNSD . New material PAPUA NEW GUINEA • 1 ♂ , 3 ♀♀ ; “ Deutsch N. Guinea [p, blue label]// Gehr. W. Müller Vermächt. 1909 [p, blue label]// Staatl. Museum für Tierkunde Dresden [p]”; SNSD . Heller (1914: 628) based his description of M. vicinus on an unstated number of specimens. At least two specimens with nearly identical labels are allocated in SNSD . The lectotype here designated is the only syntype with Heller’s original handwriting on a red label, which with some confidence may indicate this specimen was originally selected by the author as holotype . The lectotype is designated in order to enhance the stability of nomenclature and fix the specimen I based my redescription on, in case other (non-conspecific) syntypes are discovered in the future. Additional SNSD specimens with slightly different labels (see Checklist) are not considered syntypes since Heller (1914) in the original description questioned the origin of the available specimens: “Hab. Nova Guinea (Germanica? …)” but additional specimens provided with labels exactly specifying that they coming from the former German New Guinea (“Deutsch N. Guinea ”). Description MEASUREMENTS. Total body length 6.20 ( lectotype ) to 6.90 mm . Dorsum uniformly brown, forebody dorsally with very vague green lustre, venter and appendages paler brown. Head slightly convex dorsally between compound eyes, glossy dorsally and ventrally. Male labroclypeus ( Fig. 190 ) broadly V-shaped emarginate on anterior margin, female labroclypeus ( Fig. 189 ) subtruncate to very broadly emarginate, its lateral margins slightly sinuous (in male) to nearly straight (in female) in both dorsal and lateral views. Anterolateral angles of labroclypeus obtuse, nearly right-angled and moderately strongly protruding anteriad in male, rounded and not projecting in female, raised up at angle of nearly 60-70° to frons in lateral view. Anterior and lateral margins of labroclypeus smooth. Upper- and underside of labroclypeus with sparse inconspicuous setae along anterior and lateral margins. Canthus obtuse angulate in dorsal view. Punctures of frons moderately deep and large, annular. Intervening spaces glossy, generally smaller than punctures. Head setae inconspicuous, suberect; each seta rises from anterior margin or centre of corresponding puncture, surpassing its length. Antenna 9-segmented, club 3-lamellate. Pronotum transverse, flattened dorsally, glossy dorsally, subopaque laterally. Anterior margin of pronotum deeply emarginate with anterolateral angles protruding anteriad. Basal margin of pronotum broadly rounded. Lateral margin of pronotum broadly rounded, delicately crenulate all along (intervals between crenulae narrow, crenulae nearly merged) ( Fig. 262 ). Moderately long suberect curved seta present between every two crenulae. Lateral margin of pronotum slightly sinuous in lateral view. Hypomeron separated from prosternum by moderately low slightly curved carina, with long setae on its anterolateral margin opposite to compound eye ( Fig. 284 ). Antennal pocket moderately deep. Pronotal punctures ovoid, annular, shallow. Intervening spaces variably large, generally smaller than punctures. Setation as on head but setae longer and curved. Scutellar shield pointed apically. Elytron opaque, with tracks of three-four flat almost entirely glabrous longitudinal carinae, including sutural one. Elytral punctures linear (elongate and narrow), incision-shaped, shallow ( Fig. 353 ). Intervening spaces densely microreticulate. Appressed to suberect seta rises from anterior margin of each puncture, not surpassing length of corresponding incision. Disc and lateral margins of elytra in part covered with microscopical velvety pubescence. Male pygidium flattened dorsally, with large and shallow annular punctures (Fig. 530). Female pygidium flattened dorsally, with small median hump (Fig. 529). Intervening spaces generally much smaller than punctures, subopaque. Setae of pygidium suberect, sparse. Protibia widened distally, with three acute external teeth ( Fig. 425 ). Male protibial terminal spur straight, narrow and pointed, female one short and somewhat thickened. Tarsal claws with pulvilli. Aedeagus as in Figs 736–738 . Sexual dimorphism Female lamellae of antennal club shorter; female anterolateral angles of labroclypeus less strongly protruding anteriad.