Maechidius aenescens Heller, 1910

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 : 16-17

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.4344265
persistent identifier	https://treatment.plazi.org/id/1A3787F6-9D13-924B-FDD5-F983C9C72F8A
treatment provided by	Valdenar
scientific name	Maechidius aenescens Heller, 1910
status

Treatment

Maechidius aenescens Heller, 1910 View in CoL

Figs 18 View Figs 18–21 , 97 View Figs 97–108 , 197 View Figs 193–207 , 266 View Figs 266–277 , 286 View Figs 286–301 , 359, 451

Type material

Lectotype [herewith designated] PAPUA NEW GUINEA • ♀; “ Kais.Wilhelmsland Paup Dr.Schlaginhaufen [p, blue label] //1910 [p] 1 [h] [blue label] // aenescens Heller [h, red label] // Staatl. Museum für Tierkunde.Dresden [p]”; SNSD.

Paralectotypes

PAPUA NEW GUINEA • 3 ♀♀; “ Kais.Wilhelmsland Paup Dr.Schlaginhaufen [p, blue label] // 1910 [p] 1 [h] [blue label]// Staatl. Museum für Tierkunde.Dresden [p]”; SNSD • 1 ♀; “ Kais.Wilhelmsland Paup Dr.Schlaginhaufen [p, blue label] // 1910 [p] 1 [h] [blue label] // ♀ [h]// Staatl. Museum für Tierkunde. Dresden [p]”; SNSD .

New material

PAPUA NEW GUINEA • 1 ♀; “Collection Naturhistorisches Museum Basel // Papua New Guinea Madang Prov. L. Cizek lgt. // Salemben village 145°24’E 4°42’S 16.XII. 2000, 750 m”; NHMB GoogleMaps .

Heller (1910: 22) based his description of M.aenescens on a number of specimens –although not explicitly stated, he gives a range of sizes. The four paralectotypes ( SNSD) do not bear a type label. However, the locality label has the same text and handwriting as in the only specimen labelled “ aenescens ”. The lectotype here designated is the only syntype in Heller’s original handwriting on a red label, which may indicate (but cannot be stated with confidence), that this specimen was selected by the original author as the holotype. The lectotype designation is made in order to enhance the stability of nomenclature and fix all 5 of Heller’s specimens as members of the type series.

Description

MEASUREMENTS. Total body length 6 (lectotype) to 7.40 (largest paralectotype) mm.

Dorsum and venter brown, forebody with slight green lustre. Head flattened dorsally, somewhat depressed on either side at anterior angle of labroclypeus, slightly glossy dorsally and ventrally. Female labroclypeus subtruncate anteriorly ( Fig. 97 View Figs 97–108 ), its lateral margins sinuous in both dorsal and lateral views, anterolateral angles large, obtuse angulate and raised up at angle of nearly 90° to frons in lateral view. Anterior and lateral margins of labroclypeus smooth. Upper- and underside of labroclypeus with sparse long setae along anterior and lateral margins. Canthus broadly rounded to obtuse angulate in dorsal view. Punctures of frons annular, large and shallow. Intervening spaces with very delicate microreticulation, generally larger than punctures. Pubescence scale-like, elongate, variably long. Some setae very short, much shorter than their corresponding punctures. Each seta rises from anterior margin of corresponding puncture. Female antenna 9-segmented, club 3-lamellate. Pronotum transverse, flattened dorsally, glossy dorsally and laterally. Anterior margin deeply emarginate with anterolateral angles protruding anteriad. Basal margin sinuous to broadly rounded. Lateral margin broadly rounded, delicately crenulate all along ( Fig. 197 View Figs 193–207 ). Moderately long curved and appressed scale-like seta present between every two crenulae. Lateral margin of pronotum nearly straight in lateral view except in basal fourth. Hypomeron separated from prosternum by low straight carina, with very long setae on its anterolateral margin opposite to compound eye ( Fig. 266 View Figs 266–277 ). Antennal pocket shallow. Disc with shallow annular punctures, intervening spaces glossy and generally larger than those. Setae similar to those on head, appressed, generally longer. Some setae very short, much shorter than their corresponding punctures. Scutellar shield broadly rounded apically. Elytron glossy, with or without tracks of two vague, almost entirely glabrous longitudinal carinae. Sutural carinae not present. Punctures of elytral disc small, ordinary, intervening spaces in part densely wrinkled, in part glossy ( Fig. 286 View Figs 286–301 ). Setae shorter than those on pronotum, appressed; setae arranged in in part irregular paired longitudinal rows. Most setae extending exactly from one puncture to the next. Female pygidium flattened dorsally, with very large dense punctures which are shagreened on background ( Fig. 451 View Figs 451–468 ). Intervening spaces of pygidium glossy, much smaller than punctures. Protibia widened distally, in female with three external teeth: two large acute distal and one inconspicuous strongly obtuse basal (Fig. 359). Protibial terminal spur not present (in females only?). Tarsal claws with pulvilli (in females only?).

Sexual dimorphism

Male is unknown.