Maechidius ursus Telnov 2020, sp. nov.
Creators: name: Telnov, Dmitry
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Scarabaeidae
Maechidius
Maechidius ursus

description: Maechidius ursus sp. nov.
urn:lsid:zoobank.org:act: 395C3699-19FC-48D0-BAAD-689558BC2BF6
Figs 92, 188, 261, 352, 358, 424, 444, 528
Differential diagnosis
This is a very distinctive species among all congeners primarily due to the strongly bigibbose frons, the flattened and enlarged lateral margins of the pronotum, the metatibia being smooth and glabrous on the inner surface but dense long setose on the external surface, the single long terminal spur of the metatibia, and the peculiar long fur-like setae. It is closest to Maechidius opatroides Arrow, 1941 comb. rest. from Waigeo Island (consider the new combination above), but in this species (of which only females are known) the clustered brush-like setae are much more slender, appressed and shorter, the lateral margin of the pronotum is evenly emarginate postmedially (not angulate), the sutural carina of the elytron is not indicated, the metatibia is less wide, the anterolateral angles of the labroclypeus are obtuse angulate and not protruding anteriad and the labroclypeus is generally wider than in M. ursus sp. nov.
Etymology
The specific name is derived from the Latin Ursus (bear), indicating the robust body and peculiar, dense, mammal-fur-like pubescence. Noun in apposition.
Type material
Holotype
INDONESIA • ♀; “ INDONESIA E, Prov. Raja Ampat, Misool SW, distr. Misool Utara, Aduwey (Adua) vill. ~ 5 km NNE, valley of River Ifeylo, 01°58’41”S, 129°55’18”E, 28.III.2009, edge of primary lowland rainforest, white light”; NME.
Description
MEASUREMENTS. Holotype, total body length 8.60 mm. Head 1.70 mm long, across eyes 1.75 mm wide. Pronotum 1.80 mm long, maximum width 3.20 mm. Elytral length 5.10 mm, maximum combined width 3.70 mm.
Dorsum and venter covered with microscopical velvety pubescence, uniformly dark brown with reddish brown mouthparts, antennae and legs. Head slightly transverse, opaque dorsally and ventrally except for glossy labroclypeus, vaguely impressed on labroclypeus anterior to each compound eye and with paired strong obtuse hump between eyes. Compound eye large, occupying more than half side of head. Female labroclypeus (Fig. 188) broadly and moderately deep emarginate anteriorly, lateral margins nearly straight in dorsal, slightly sinuous in lateral view, anterolateral angles moderately protruding, acute in dorsal view, bent up at ~90° to frons in lateral view. Canthus straight in dorsal view. Anterior and lateral margins of labroclypeus smooth. Head punctures circular, moderately deep, variably large. Intervening spaces microreticulate and glabrous, variably large. Conspicuous rather long appressed to suberect brush of clustered setae rises from each puncture (Fig. 358). 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 bulbous, subspherical, slightly longer than wide. Pronotum opaque dorsally and laterally. Anterior margin of pronotum slightly sinuous with anterolateral angles (stronger) and mesal portion (inconspicuously) protruding anteriad. Basal margin of pronotum sinuous. Circular moderately deep impression on either side of pronotum opposite posterolateral angle. Lateral margin of pronotum strongly flattened and expanded laterally, bent up with regard to axis of pronotal disc, evenly widened towards midlength, strongly emarginate postmedially towards nearly posterolateral angles (Fig. 261). Crenulae of lateral margin large, long erect scale-like seta present between every two crenulae. Lateral margin of pronotum straight in lateral view. Pronotal punctures circular, moderately large and deep. Intervening spaces microreticulate and glabrous, generally larger than punctures, in part covered with microscopical velvety pubescence. Setae as conspicuous as on head (Fig. 358), shorter and sparser on disc, much longer and denser on anterior part and along lateral sides. Hypomeron slightly emarginate and very long setose on anterior margin, which is well-projected and flange-like.Antennal pocket moderately deep. Median anterior process of prosternum long, narrow, flange-like raised. Scutellar shield obtusely pointed apically. Elytra slightly widened in median part, maximum width across median third, opaque dorsally, with distinct humeri.Distinct obtuse triangular hump at apex of each elytron.Two flat longitudinal carinae on each elytron. Sutural carinae well developed, raised, nearly complete. Elytral disc with rather large deep cylindrical punctures which are irregular in apical half, becoming arranged in striae in apical third (Fig. 352). Intervening spaces microreticulate, covered with microscopical velvety pubescence, variably large but generally about as large as punctures. Setae inconspicuous, short and sparse, suberect seta rises from anterior part of each puncture. Epipleuron all along with conspicuous short brush-like setae. At apical margin with transverse brush of dense posteriad-directed brush-like setae, elytral apices therefore look flattened and slightly prolonged (Fig. 92). Female pygidium dorsally impressed, regularly circular punctured, antero-medially with a group of dense brush-like setae (Fig. 528). Venter covered with sparse shallow circular punctures, each provided with appressed conspicuous brush-like seta. Legs long and slender. Protibia nearly straight (crenulate) on external margin, with delicate incomplete dorsal carina. Female protibia with obtuse distal tooth and rudimentary predistal one (Fig. 424). Protibial terminal spur long, nearly straight, obtuse. Female metatibia flattened and glabrous on inner margin (Fig. 444). Metatibial terminal spur single, long, obtuse. Tarsal claws without pulvilli (in female only?).
Sexual dimorphism
Male unknown.
Ecology
Attracted to white light in river valley surrounded by primary lowland rainforest.
Distribution
Hitherto only known from Misool, Raja Ampat Islands, Indonesia.
description: Published as part of Telnov, Dmitry, 2020, 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, pp. 1-210 in European Journal of Taxonomy 721 on pages 122-124, DOI: 10.5852/ejt.2020.721.1127, http://zenodo.org/record/4122118