Maechidius yamdena, Telnov, 2020

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, European Journal of Taxonomy 721, pp. 1-210 : 129-130

publication ID	https://doi.org/ 10.5852/ejt.2020.721.1127
publication LSID	lsid:zoobank.org:pub:89E62EF8-2E45-4C59-94B7-6A5603E8939B
DOI	https://doi.org/10.5281/zenodo.14371064
persistent identifier	https://treatment.plazi.org/id/E3C00D89-AD86-4615-A09A-CA0CD01E1DC4
taxon LSID	lsid:zoobank.org:act:E3C00D89-AD86-4615-A09A-CA0CD01E1DC4
treatment provided by	Valdenar
scientific name	Maechidius yamdena
status	sp. nov.

Treatment

Maechidius yamdena View in CoL sp. nov.

urn:lsid:zoobank.org:act:E3C00D89-AD86-4615-A09A-CA0CD01E1DC4

Figs 96 View Figs 94–96 , 195–196 View Figs 193–207 , 265 View Figs 259–265 , 356 View Figs 349–358 , 428 View Figs 424–435 , 441–442, 447–448 View Figs 436–450 , 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 View Figs 193–207 ) 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 View Figs 193–207 ) 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 View Figs 259–265 ). 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 View Figs 349–358 ). 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 View Figs 424–435 ), 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 View Figs 436–450 ). Protibial terminal spur short, straight, acute ( Figs 447–448 View Figs 436–450 ). Metatibial terminal spurs paired, acute in male ( Fig. 442 View Figs 436–450 ), rounded in female ( Fig. 441 View Figs 436–450 ). Tarsal claws in both sexes with large pulvilli. Spiculum gastrale as in Fig. 547 View Figs 545–569 . Male aedeagus as in Figs 745–747 View Figs 739–750 .

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.