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

description: Maechidius trivialis sp. nov.
urn:lsid:zoobank.org:act: F2D2D566-54D2-4033-ADC1-2742DF86AA32
Figs 91, 187, 260, 283, 351, 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) 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). 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). 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). 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. Aedeagus as in Figs 733–735.
Sexual dimorphism
Female is unknown.
Ecology
Inhabits lowland rainforests.
Distribution
Papuan Peninsula of New Guinea.
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 121-122, DOI: 10.5852/ejt.2020.721.1127, http://zenodo.org/record/4122118