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

description: Maechidius yamdena sp. nov.
urn:lsid:zoobank.org:act: E3C00D89-AD86-4615-A09A-CA0CD01E1DC4
Figs 96, 195–196, 265, 356, 428, 441–442, 447–448, 534, 547, 745–747
Differential diagnosis
This species is peculiar due to the combination of the following characters: structure of labroclypeus, shape of lateral margins of pronotum, rugulose punctures of elytra, very short dorsal setae and shape of male aedeagus.
Etymology
Named after the Yamdena, the main tribe and language of the main island in the Tanimbar group. Noun in apposition.
Type material
Holotype
INDONESIA • ♂; “INDONESIA Tanimbar Islands Yamdena Is. January 2009 BMNH {E} 2015-77 ”; BMNH.
Paratypes (28 specimens)
INDONESIA • 26 specs; same label as for holotype; BMNH • 1 ♂, 1 ♀; same label as for holotype; DTC.
Description
MEASUREMENTS. Holotype, total body length 8.05 mm. Head 1.45 mm long, across eyes 1.90 mm wide. Pronotum 1.80 mm long, maximum width 2.80 mm. Elytral length 4.80 mm, maximum combined width 3.80 mm. Paratypes up to 9.20 mm long.
Dorsum and venter uniformly black-brown with reddish brown labroclypeus, mouthparts, antennae, tibiae and tarsi. Head transverse, glossy dorsally and ventrally, somewhat convex between eyes and vaguely impressed on labroclypeus anterior to each compound eye. Compound eye large, occupying about half side of head. Male labroclypeus (Fig. 195) broadly and moderately deep emarginate anteriorly, its lateral margins sinuous in both dorsal and lateral views, anterolateral angles moderately protruding, to slightly acute in dorsal view, bent up at ~90° to frons in lateral view. Female labroclypeus (Fig. 196) somewhat shallower emarginate anteriorly, with anteriorly less protruding anterolateral angles. Upperand underside of labroclypeus with sparse long setae along anterior and lateral margins. Canthus obtusely angulate in dorsal view. Anterior and lateral margins of labroclypeus smooth. Head punctures irregularly shaped, moderately deep, variably large. Intervening spaces glossy and glabrous, variably large, generally smaller than punctures. Moderately long suberect seta rises from anterior margin of each puncture, surpassing its length. Antenna 8-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. Pronotum glossy dorsally and laterally. Anterior margin of pronotum slightly sinuous with anterolateral angles (stronger) and mesal portion (inconspicuously) protruding anteriad. Basal margin of pronotum very broadly rounded. Lateral margin of pronotum evenly rounded, shallowly emarginate in front of posterolateral angles (Fig. 265). Crenulae of lateral margin delicate, short seta present between every two crenulae. Lateral margin of pronotum slightly sinuous in lateral view. Pronotal punctures ovoid (more circular along lateral sides), horseshoe-shaped, variably large, deep. Intervening spaces glossy and glabrous, variably large but generally much smaller than punctures. Pronotal setae inconspicuous, suberect, shorter than those on head, not or hardly surpassing length of corresponding punctures, appressed to median (raised) part of corresponding horseshoe-shaped puncture. Hypomeron slightly curved and very long setose on anterior margin which is moderately raised. Antennal pocket moderately deep. Median anterior process of prosternum long brushy setose, broad, moderately raised. Scutellar shield rounded apically. Elytra slightly widened in posterior half, maximum width across apical third, slightly glossy dorsally, with distinct humeri. Inconspicuous obtuse transverse hump at apex of each elytron. Tracks of four to five inconspicuous flat glabrous longitudinal carinae on each elytron (including one sutural and two lateral). Elytral disc in part wrinkled, punctures sinuous (elongate and narrow), incision-shaped, moderately deep (Fig. 356). Elytral setae inconspicuous, appressed except on apices; seta rises from anterior margin of each puncture, not surpassing length of corresponding incision. Upper carina of epipleuron all along with short suberect setae. Male and female pygidium flat to slightly convex, with large irregularly shaped shallow annular punctures and short almost erect setae, which rise from centre of each puncture (Fig. 534). Venter covered with sparse large shallow annular punctures, each provided with short seta. Legs long and slender. Protibia nearly straight on external margin, with delicate dorsal carina. Three obtuse external teeth on protibia: distal narrower, median somewhat larger and broader, basal one less prominent (Fig. 428), nearly disappearing in some males. Basal protarsomere lengthened, asymmetrical, distinctly widened distally, concave ventrally, with short acute ventro-lateral denticle at inner distal margin which is larger in male than in female (Fig. 447). Protibial terminal spur short, straight, acute (Figs 447–448). Metatibial terminal spurs paired, acute in male (Fig. 442), rounded in female (Fig. 441). Tarsal claws in both sexes with large pulvilli. Spiculum gastrale as in Fig. 547. Male aedeagus as in Figs 745–747.
Sexual dimorphism
Poorly indicated. Female generally more robust than male, with comparatively smaller lamellae of antennal club, anterior margin of labroclypeus shallower emarginate, somewhat longer protibial terminal spur and dorsally flat pygidium. The ventro-lateral denticle of the basal protarsomere is larger in the male than in the female.
Ecology
No data available.
Distribution
Hitherto only known from Yamdena, the main island of the Tanimbar Islands, SE Moluccas, 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 129-130, DOI: 10.5852/ejt.2020.721.1127, http://zenodo.org/record/4122118