Maechidius trivialis, 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 : 121-122

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.4344323
persistent identifier	https://treatment.plazi.org/id/F2D2D566-54D2-4033-ADC1-2742DF86AA32
taxon LSID	lsid:zoobank.org:act:F2D2D566-54D2-4033-ADC1-2742DF86AA32
treatment provided by	Valdenar
scientific name	Maechidius trivialis
status	sp. nov.

Treatment

Maechidius trivialis View in CoL sp. nov.

urn:lsid:zoobank.org:act:F2D2D566-54D2-4033-ADC1-2742DF86AA32

Figs 91 View Figs 90–93 , 187 View Figs 181–192 , 260 View Figs 259–265 , 283 View Figs 278–285 , 351 View Figs 349–358 , 423, 527, 566, 733–735

Differential diagnosis

Among congeners with a brown body, Maechidius trivialis sp. nov. is the only one with a truncate male labroclypeus with anterolateral margins not protruding anteriad. The male aedeagus is different from that of any known congener.

Etymology

The specific name is derived from the Latin ‘ trivialis ’ (meaning ‘trivial’, ‘ordinary’).

Type material

Holotype

PAPUA NEW GUINEA • ♂; “Aquatic. [p] // Lower rain forest, 1,300 ft. [p] // PAPUA:Kokoda. 1,200ft. viii.1933. L.E.Cheesman. B.M.1933-577. [p, corrected by hand]”; BMNH.

Description

MEASUREMENTS. Holotype, total body length 6.10 mm. Head 1.10 mm long, across eyes 1.30 mm wide. Pronotum 1.55 mm long, maximum width 2.25 mm. Elytral length 3.45 mm, maximum combined width 2.70 mm.

Dorsum and venter brown, forebody with inconspicuous green lustre. Frons flattened dorsally, head dorsum subopaque dorsally and ventrally. Male labroclypeus ( Fig. 187 View Figs 181–192 ) truncate anteriorly and bent up, its lateral margins slightly sinuous in both dorsal and lateral views, anterolateral angles obtuse and not protruding anteriad. Anterior and lateral margins of labroclypeus smooth. Upper- and underside of labroclypeus with long setae along anterior and lateral margins. Compound eye moderately large, not globose. Canthus broadly rounded in dorsal view. Head punctures irregularly circular, shallow, moderately dense. Intervening spaces with very delicate microreticulation, variably large. Pubescence inconspicuous, appressed; seta rises from anterior margin of each puncture, hardly surpassing length of corresponding puncture. Canthus with several much longer and stronger erect setae. Male antenna 9-segmented, club 3-lamellate. Antennomere 2 bulbous, trapezoid, slightly transverse. Pronotum transverse, flattened dorsally, subopaque dorsally and laterally. Anterior margin of pronotum broadly emarginate with anterolateral angles slightly protruding anteriad. Basal margin of pronotum very broadly rounded. Lateral margin of pronotum in dorsal view broadly rounded, crenulate all along; crenulae becoming more delicate towards base ( Fig. 260 View Figs 259–265 ). Moderately long curved seta present between every two crenulae. Lateral margin of pronotum nearly straight in lateral view. Hypomeron separated from prosternum by low straight carina, with moderately long setae on its anterolateral margin opposite to compound eye ( Fig. 283 View Figs 278–285 ). Antennal pocket shallow. Pronotal disc with shallow rather sparse circular to ovoid punctures, intervening spaces delicately microreticulate, variably large. Setae generally shorter than those on head, appressed, not surpassing length of corresponding punctures. With row of longer suberect setae along basal margin of pronotum. Scutellar shield triangular, pointed apically. Elytron cylindrical, glossy, without tracks of longitudinal carinae except for raised, rather broad sutural carina. Punctures of elytral disc double. Ordinary punctures of disc shallow, of irregular shape. Each ordinary puncture supplemented with shallow linear (narrow and long) incision-shaped puncture ( Fig. 351 View Figs 349–358 ). Elytral setae inconspicuous, appressed; seta arises from anterior margin of each incision, not surpassing its length. Male pygidium flattened dorsally, with large dense shallow annular punctures (Fig. 527). Intervening spaces glossy, smaller than punctures. Setae of pygidium rise from either anterior margin or centre of each puncture, in anterior half appressed and generally not surpassing length of corresponding punctures, in apical half distinctly longer, suberect. Male protibia with three external teeth: two very large acute distal and one very inconspicuous strongly obtuse basal (Fig. 423). Male protibial terminal spur not present. Male metataibial terminal spurs long, pointed and somewhat curved apically. Tarsi long and slender, slightly shorter than corresponding tibiae. Tarsal claws with pulvilli (in males only?). Spiculum gastrale as in Fig. 566 View Figs 545–569 . Aedeagus as in Figs 733–735 View Figs 726–738 .