Rhyparus bacanensis, Minkina & Anichtchenko & Vasiljeva & Skelley, 2022

Minkina, Ÿukasz, Anichtchenko, Alexander, Vasiljeva, Anastasija & Skelley, Paul E., 2022, Four new species of the genus Rhyparus Westwood, 1845 (Coleoptera: Scarabaeidae: Aphodiinae) with modified pygidium and last abdominal ventrite in females, Baltic Journal of Coleopterology 22 (1), pp. 81-101 : 82-84

Rhyparus bacanensis sp. nov.

( Figs. 1–3 , 20 , 26 )

Type locality. Indonesia, Moluccas North , Bacan Island, Mount Sibela, 5 km SE of Makian vill .

Type material. Holotype (): Indonesia, N Moluccas | 500­ 750m., Bacan Island | SE slopes of Mt. Sibela | 5 km SE of Makian vill. | 2­ 12.v.2008, leg. S. Jakl || ( Ÿ MCN).

Four new species of the genus Rhyparus Westwood, 1845 ( Coleoptera : Scarabaeidae : Aphodiinae ) with modified...

Description of the holotype. Dorsum ( Fig. 1 ). Length: 7.2 mm; maximum width: 2.25 mm. Body large­sized for members of this genus, elongate, not so distinctly convex, flattened in central part; weakly shiny; apparently almost glabrous, though partly clothed with very small yellowish macrosetae on head and all longitudinal costae on pronotum and elytra. Brownish to dark brown; antennae, tarsomeres and mouth parts pale brown.

Head ( Fig. 20 ) moderately shiny, tops of costae distinctly shiny; transversely sub­hexagonal; clypeus trapezoidal in outline, anteriorly truncate, on sides weakly upturned as obtuse, weak tooth, and later sinuous on either side; genae distinctly more excavate than eyes; clypeal disc distinctly convex, ringed by a deep groove; convexity with a pair of quite distinct, very short, convergent ridges, nearly on whole surface with distinct, fine punctures bearing small macrosetae. Frons with four distinct, longitudinal ridges with similar structure as ridges on clypeal convexity. Head covered by quite regularly spaced, quite dense, moderately large punctures bearing small macrosetae.

Pronotum very weakly shiny, tops of costae distinctly shiny; with eight distinct costae and seven intercostae, with two lateral, rounded lobes on each side. Anterior lobes somewhat higher and distinctly narrower than posterior, on the top are the widest part of pronotum. Costae of middle, third and fourth pair not interrupted in basal part

Minkina Ł., Anichtchenko A., Vasiljeva A., Skelley P.E.

of apical half, very gently convergent, distinctly convergent in the middle of apical third; second pair of costae distinctly interrupted in basal part of apical half; costae on each side with very small punctures bearing very small macrosetae. All intercostae in anterior part without additional short costae. Median intercostae with dense punctures, quite distinctly concentrated around median part into longitudinal line, all intercostae in basal part with distinct, dense punctation.

Scutellum almost imperceptible.

Elytra moderately shiny, tops of costae and preapical glandular area more distinctly shiny. Each elytron with six elevated costae, and five flat intercostae. Costae on sides with very small punctures bearing very small macrosetae. Preapical glandular area relatively small. Intercostae first to fourth with two distinct rows of punctures; on third intercostae there is very short additional costae with very short additional row of punctures here, however there are simple, sparsely located, much smaller punctures punctures almost until apex. Fifth intercosta with one row of punctures; in basal part of fourth intercosta there is region with extremely short additional costa, with some additional punctures.External caudal bulb distinctly reduced, area between external caudal bulb and sides of elytra not divided; external and medio­internal caudal bulbs not divided; medio­internal caudal bulb shortened, transversally rounded, internally stretched.

Pygidium ( Fig. 26 ) with dense, irregularly spaced punctation, with weak longitudinal rib in the middle and deep excisionon its sides; with distinctly longitudinal apex in the shape of distinct triangle.

Venter ( Fig. 2 ) moderately shiny. Meso­metaventral plate flattened in the middle, with distinct, narrow, quite deep longitudinal furrow; punctation of meso­metaventral plate dense, quite regularly spaced, irregular in size; all punctures bearing short macrosetae.Abdominal ventrites moderately shiny, on sides with rows of punctures; with an additional punctured furrow in basal part. Last abdominal ventrite with dense punctures, which are about one and half time larger than on last but one ventrite; in basal half in the middle part with dense, very deep, longitudinal rows; in apical part in the middle with very deep groove, clearly located much below apex of pygidium.

Meso­ and metafemora with two very indistinct tubercles on lower border; all femora shiny, with regular, very distinct, rather small, very dense punctation; all punctures bearing small macrosetae.

Variation. Unknown.

Sexual dimorphism. Unknown. When we look at shape of meso­metaventral plate and apex of mesotibiae we can suppose that sexual dimorphism it is like typical for a whole genus (except pygidium and last ventrite).

Etymology. Toponymic; an adjective derived from the name of Bacan Island – where the holotype was collected.

Affinity. See discussion and tables 1 and 2.

Figures

Figs. 1–3. Rhyparus bacanensis sp. nov., view. Scale lines: 1.0 mm.

Figs. 20–25. Heads: 20 – R. bacanensis sp. nov.,, holotype; 21 – R. buruensis sp. nov.,, holotype; 22 – R. fijiensis sp. nov.,, holotype; 23 – R. stebnickae sp. nov.,, holotype; 24 – R. paraphilippinensis Ochi & Kakizoe, 2021,; 25 – R. sepikensis Stebnicka, 1998,, paratype. Scale lines: 1.0 mm.

Figs. 26–33.Abdominal apexes with black­white miniatures of pygidium on left­down side: 26 – R. bacanensis sp. nov.,, holotype; 27 – R. buruensis sp. nov.,, holotype; 28 – R. fijiensis sp. nov.,, holotype; 29 – R. stebnickae sp. nov.,, holotype; 30 – R. approximans Fairmaire, 1893,; 31 – R. loebli Paulian, 1983,; 32 – R. paraphilippinensis Ochi & Kakizoe, 2021,; 33 – R. sepikensis Stebnicka, 1998,, paratype. Scale lines: 0.5 mm.