Maechidius echinoides Prokofiev, 2022

Prokofiev, Artem M., 2022, New species and records of Maechidius Macleay, 1819 from New Guinea (Coleoptera: Scarabaeidae: Melolonthinae), Zootaxa 5205 (5), pp. 445-462 : 451-453

Maechidius echinoides Prokofiev , new species

Fig. 5

Type material. Holotype, male ( Fig. 5A ): “Mäanderberg 387 / 1.-9.8.13 / Bürgers S.G.” ( ZMHB) . Paratypes: 2 females: “D. N. Guinea / Mäanderberg / 1.-10.VIII.13 / Kais. Augustafl. Exp. / Bürgers S.G.” ( ZMHB) ; 1 female: same data, but 19.-31.VII.13 ( ZMHB) .

Description of the holotype. Total body length 8.5 mm, greatest width 4.2 mm. Dark reddish-brown, glossy, forebody and fore legs darker than rest of body; antennae and palpi reddish; setation yellowish.Antennae 9-segmented, club 3-lamellate, as long as funicle. Labroclypeus broadly concave anteriorly, its lateral margins strongly sinuous in both dorsal and lateral views; anterolateral angles protruding, sharpened, reflexed; canthus angulate. Dorsal surface of labroclypeus densely punctured, punctures deep, annular to hexagonal or slightly oblong, increasing in size from anterior margin of labroclypeus to frons; setae erect, much exceeding diameter of corresponding puncture in length, longer on frons than on labroclypeus. Underside of labroclypeus densely setose. Frons flat. Punctures on dorsal head and pronotum with dense microscopical velvety pubescence; intervening spaces narrow, in part ridge-like, smooth and glossy. Pronotum transverse, with anterior margin concave and weakly bisinuate, anterolateral angles strongly protruding, acute. Sides of pronotum more convex anteriad than posteriad, widest at middle, slightly constricted postmedially, denticulate all along (about 18 denticles); basal margin evenly convex; posterolateral angles obtuse. Punctures on pronotum almost equal to those on frons in size, annular or hexagonal to oblong, setigerous, with setae erect, much exceeding their diameter in length, almost equal to only slightly shorter than diameter of compound eye; the similarly long setae present between every two lateral denticles. Hypomeron separated from prosternum by rather high emarginate carina bearing long setae; antennal pockets moderately deep. Punctures of hypomeron shallow, annular, setigerous, somewhat more densely arranged anteriorly than posteriorly; setae not suprassing diameter of punctures; intervening spaces smooth and glossy. Scutellar shield apically pointed, rather densely punctured; setae adpressed, hardly surpassing diameter of punctures; intervening spaces microreticulate, matt. Elytra slightly widened posteriad, broadly rounded apically, with very indistinct traces of longitudinal carinae. Punctures of elytral disc long and narrow, incision-shaped; intervening spaces in part microreticulate and opaque, in part smooth and glossy; setae erect, much exceeding length of corresponding punctures. Pygidium weakly convex on disc and slightly impressed along sides, densely punctured with annular punctures becoming smaller toward apex; intervening spaces very narrow, smooth and glossy; setae erect, much exceeding diameter of punctures in length. Thorax and abdominal ventrites densely punctured, with punctures annular, larger in size toward mid-ventral line, setigerous; intervening spaces smaller than diameter of punctures, smooth and glossy; setae semi-erect, becoming longer toward mid-ventral line, those on abdominal ventrites longer than on thorax, up to twice longer than diameter of corresponding puncture. Ventral profile of abdomen weakly concave. Protibia ( Fig. 5B ) widened distally, with delicate longitudinal carina dorsally, with two long and sharp apical teeth and very vague basal tooth; protibial spur straight, pointed. Metatibial spurs very slightly unequal in size, not sharpened at tip. All tarsomeres ordinary. Tarsal claws with pulvilli. All legs with long setae. Aedeagus and spiculum gastrale, as on Figs. 5C–F ; parameres with lateral margins sinuous in dorsal view, lateral sides with bipartite longitudinal impression; spiculum gastrale strongly bent.

Females. Total body length 8.5–10.2 mm, greatest width 4.2–4.8 mm. From reddish- to blackish-brown. Labroclypeus shallowly and broadly emarginated anteriorly, its lateral sides bisinuate to almost regularly convex from anterolateral angles to canthus; anterolateral angles usually less protruding than in male and rounded. Antennal club as long as in male. Sides of pronotum denticulate, with 17–20 denticles. Ventral profile of abdomen weakly concave to almost straight. Distalmost tooth on protibia longer than in male ( Fig. 5G ). Metatibial spurs also longer, with tips blunt, almost truncate.

Differential diagnosis. This species shows no external differences from M. esau Heller, 1914 and has a very similar aedeagus; however, in contrast to the latter, the lateral impression of parameres is bipartite, and lateral margins of parameres are distinctly angulate in the dorsal view in the new species ( Figs. 5C–D ; Telnov 2020: figs. 614–616). The spiculum gastrale is also different in shape ( Figs. 5E–F ; Telnov 2020: fig. 561).

Etymology. The species name (meaning hedgehog-like in Latin) is given in reference to the long setation of this new species.

Figures

FIGURE 5. Maechidius echinoides Prokofiev, new species. (A) dorsal view, holotype; (B) protibia, holotype; (C) aedeagus, lateral view, holotype; (D) parameres, dorsal view, holotype; (E) spiculum gastrale, lateral view, holotype; (F) ditto, dorsal view; (G) protibia, female paratype. Scale bars: (A) 1.5 mm; (B, G) 1.0 mm; (C–F) 0.5 mm.