Frolov, A.V. 2008. A new apterous species of the genus Orphnus MacLeay (Coleoptera: Scarabaeidae: Orphninae) from South Africa. Zootaxa, 1855: 65–68.

A new apterous species of the genus Orphnus MacLeay (Coleoptera: Scarabaeidae: Orphninae) from South Africa

A.V. Frolov

Laboratory of Insect Systematics, Zoological Institute, Russian Academy of Sciences, Universitetskaya nab., 1, 199034 Sankt-Petersburg, Russia. Email: afrolov@zin.ru

Abstract

A new apterous species of the genus Orphnus MacLeay, 1819, is described from Little Karoo (South Africa).  The new species can be separated from closely related O. luminosus Benderiter, 1920, by the shape of the parameres and sculpture of the head and pronotum.

Key words: scarab beetles, Orphnus, new species, aptery, South Africa, Little Karoo.

Introduction 

The African continent has a diverse fauna of scarab beetles of the subfamily Orphninae with five genera and more than 100 described species (Arrow 1912, Frolov 2005).  The great majority of these species belong to the genus Orphnus MacLeay (Paulian 1948, Petrovitz 1971).  Most of the species in this genus have well-developed wings.  A few species, however, have reduced or almost absent wings.  Recently I had the opportunity to examine two apterous specimens from the Transvaal Museum, South Africa, belonging to an undescribed species similar to O. (Parorphnus) luminosus Benderitter.  This new species is described below.

The material used for this study is housed in the following institutions: Natural History Museum, Budapest (HNHM), Institut Royal des Sciences Naturelles de Belgique, Brussels (IRSNB), Musee Royal de l’Afrique Centrale, Tervuren (MRAC), Transvaal Museum, Pretoria (TMSA), Zoological Institute of Russian Academy of Sciences, Sankt-Petersburg (ZIN).  Photographs were taken with a Leica MZ9.5 stereomicroscope using dry specimens.

Figs. 1–2: Orphnus harrisoni habitus; Fig. 3: O. harrisoni aedeagus in dorsal and lateral view; Fig. 4: O. luminosus habitus; Fig. 5: O. luminosus aedeagus in dorsal and lateral view.
Figs. 1–2: Orphnus harrisoni habitus; Fig. 3: O. harrisoni aedeagus in dorsal and lateral view; Fig. 4: O. luminosus habitus; Fig. 5: O. luminosus aedeagus in dorsal and lateral view. Scales: A refers to Figs. 1, 2, 4; B refers to Figs 3, 5.

Orphnus (Parorphnus) harrisoni, sp. n.

Figs. 1–3

Type material.  Holotype male with the label "S. Afr.: Little Karoo, Raubenheimer Dam, 33°24'S 22°19'E", "22.10.1993; E-Y: 2892, ground traps 15 days, leg. Endrödy-Younga" and "ground traps with meat bait" (TMSA).  A single paratype male with the same data as the holotype (ZIN).

Description.  Holotype, male (Figs. 1, 2, 6). 

Small-sized beetle (length 6.9 mm, width 3.8 mm) with oval, strongly convex, shiny body (Fig. 1).  Color dark brown, legs and elytra lighter brown.  Head: Clypeus wide, with somewhat convex anterior margin, angulate laterally, finely bordered.  Genae very small, slightly protruding past eyes.  Eyes relatively small (their diameter 2 times smaller than distance between eye and gula in ventral view).  Frontal suture broadly interrupted in the middle.  Clypeus with short, horn-shaped tubercle.  Dorsal surface of clypeus sparsely punctate.  Labrum somewhat bilobed, wide, sinuate in the middle, relatively feebly protruding past clypeus.  Pronotum: Dorsal surface convex, trapezoidal, with rounded lateral margins and base, about 1.5 times wider than long, slightly but distinctly impressed anteromedially, without processes.  Anterior angles obtuse; posterior angles widely rounded, poorly defined in dorsal view.  Pronotum finely bordered.  Dorsal surface with rounded punctures separated by 2-4 puncture diameters on disc, punctures becoming sparser laterally.  Lateral margins with long, sparse yellowish white setae.  Scutellum: shape subtriangular, rounded apically, small (about 1/20 the length of elytra).  Elytra: Surface very convex, fused, almost as long as pronotum, without humeral umbones.  Elytra widest in the anterior 1/3.  Sutural striae almost indistinct.  Elytra sparsely punctate basally, almost impunctate on disc and apically.  Wings: Wings absent.  Legs: Protibiae with shape typical to Orphnus species, with 3 outer teeth.  Lateral margin basad of outer teeth not crenulate.  Apical spur of protibia absent.  Protarsi well developed, about 4/5 length of protibiae.  Claws 1/3 length of apical tarsomere.  Apical protarsomere as long as tarsomere 3 and 4 combined, slightly wider than other tarsomeres.  Ventral surface of protibiae smooth with 2 rows of setae along sides and a few very long setae in the middle.  Mesolegs and metalegs are similar in shape; metafemora and metatibiae about 1/8 longer than the mesofemora and mesotibiae.  Tibiae somewhat triangular with 2 apical spurs, inner margin only slightly concave with 1 transverse keel.  Upper spur of tibiae slightly longer than two basal tarsomeres.  Claws 1/3 length of apical tarsomere.  Femora almost impunctate.  Abdomen: Abdominal sternites irregularly punctate, pubescent, with sparse, long setae.  Sternite 6 medially as long as sternites 2-5 combined.  Pygidium: Surface transverse, irregularly punctate, pubescent with sparse setae.

Female.  Unknown.

Paratype.  The single paratype differs from the holotype in slightly larger size of the body (length 8.0, width 4.0 mm) and somewhat denser punctation on the pronotum.

Diagnosis.  Orphnus harrisoni can be separated from other described Orphnus species by the hook-shaped apices of the parameres (Fig. 3) and by the combination of the following characters: pronotum only slightly excavated anteriorly, without horns or processes; elytra relatively short, only slightly longer than pronotum; scutellum very short; humeral umbones and wings absent.

The new species is most similar to O. luminosus but, besides the shape of the parameres, can be separated from it by the relatively smaller elytra with almost no humeral umbones, sparser punctation of elytra, denser punctation of pronotum, and horn-shaped middle clypeal tubercle.

Distribution.  The type series was collected in the Little Karoo, a semi-arid area in the Western Cape Province of South Africa between the Swartberg and Langeberg Mountains (Fig. 6). As an apterous species, O. harrisoni may have a restricted range and to be endemic to this area.

Natural history. These beetles are probably litter dwellers but exact data are not available.  The type specimens were caught in ground traps baited with meat, but a long trap exposure suggests that the beetles were captured occasionally rather than attracted to the carrion.

Etymology.  The new species is named after James du Guesclin Harrison, a scarab beetle specialist and curator at the TMSA, who brought these peculiar beetles to my attention.

Orphnus (Parorphnus) luminosus Benderitter

Figs. 4-6

Type material examined.  Holotype female: Kisantu, P.Goossens leg. (MRAC).

Additional material examined.  ANGOLA: Quango Strom, von Mechow leg., 1 male (MRAC). BURUNDI: Mugera, 1965, J.J.Rwabuneza leg., 2 females (MRAC); Bujumbura, III-IX.1969, R.P. Giraudin leg., 5 males (MRAC).  CONGO (Brazzaville): Voka, 20.XII.1975, G.Onore leg., 1 male, 1 female (MRAC); Kindamba, Méya settelment, 13.11.1963, No 187, soil trap in savannah, Balogh and Zicsi leg., 1 male (HNHM).  DEMOCRATIC REPUBLIC OF CONGO: Sandoa, XII.1931, F.G.Overlaet leg., 8 males, 4 females (MRAC); Sandoa, XI-1931, F.G.Overlaet leg., 1 male, 2 females (MRAC); Sandoa, X-XII.1932, F.G.Overlaet leg., 1 male, 2 females (MRAC); Kundelungu, 1750 m., XI.1949, N.Leleup leg., 3 females (MRAC); Kundelungu, 6-9.II.1950, N.Leleup leg., 3 females (MRAC); Kundelungu, 1750 m., I.1950, N.Leleup leg., 1 male (MRAC); Tshibamba, II.1932, F.G.Overlaet leg., 1 female (MRAC); Tshibamba, XII.1931, F.G.Overlaet leg, 2 males (MRAC); Kapanga, II.1933, F.G.Overlaet leg., 2 males (MRAC); Kapanga, I.1933, F.G.Overlaet leg., 1 male, 2 females (MRAC); Muteba, XI.1931, G.F.Overlaet leg., 3 males (MRAC); Muteba, I.1932, G.F.Overlaet leg., 1 male, 1 female (MRAC); Kafakumba, XI.1933, G.F.Overlaet leg., 2 males, 1 female (MRAC); Mayidi, 1942, P.Van Eyen leg., 3 males, 3 females (MRAC); Thysville, 30.XI.1952, P.Basilewsky leg., 1 male, 1 female (MRAC); Kapelekese, IX.1933, G.F.Overlaet leg., 1 male (MRAC); Nioka, 1934, P.Lefevre leg., 1 male (MRAC); Tshivana, XII.1933, G.F.Overlaet leg., 1 male (MRAC); Thysville, 1959/1963, R.Michaux leg., 1 male (MRAC); Thysville, VI.1923, H.Libeau leg., 1 male (MRAC); Kafakumba, XI.1937, F.G.Overlaet leg., 1 male (IRSNB); Sandoa, X.1937, F.G.Overlaet leg., 1 male (IRSNB); Lubumbashi, 1.III.1975, W.Beun leg., 1 male (MRAC); Jadotville, XI.1950, J.-J. Van Mol leg., 1 female (IRSNB); Kinda, 1 male (MRAC); Kafakumba, I.1934, G.F.Overlaet leg., 1 male (MRAC).  MALAWI: Chinteche, 15.II.1978, R.Jocque leg., 12 males, 6 females (MRAC); Viphya Mts, Mtanga'tanga, 3.II.1976, R.Jocque leg., 1 male (MRAC).  ZAMBIA: Abercorn, 15.XII.1943, H.J.Bredo leg., 2 females (IRSNB); Mweru-Wantipa, H.J.Bredo leg., 1 female (MRAC).

Diagnosis.  Orphnus luminosus is most similar to O. harrisoni but can be distinguished from this species using the shape of the parameres (Fig. 5); the larger elytra with feebly distinct humeral umbones; the denser punctation of the elytra; the sparser punctation of the pronotum; and the somewhat triangular, keel-shaped middle clypeal tubercle (Fig. 4).

Distribution.  This species is distributed in Central Africa from Burundi in the north to Malawi in the south (Fig. 6).  Most of the collected specimens originated from southern part of the Democratic Republic of Congo.

Natural history.  Despite relatively large number of specimens captured by the past collectors, no specific data on the natural history of this species are available. This species is probably a saprophagous litter dweller like O. harrisoni.

Fig. 6: Distribution map of Orphnus harrisoni and O. luminosus.
Fig. 6: Distribution map of Orphnus harrisoni and O. luminosus.

Acknowledgments

I would like to thank James du Guesclin Harrison (TMSA), Marc De Meyer (MRAC), Otto Merkl (HNHM), and Alain Drumont (IRSNB) for loan of material.  Two anonymous reviewers made valuable comments that considerably improved earlier drafts of this manuscript.  This research was supported by a POD Wetenschapsbeleid (Belgium) grant and by the grant 07-04-00482-а from the Russian Foundation for Basic Research.

References cited

Arrow, G.J. (1912) Scarabaeidae: Pachypodinae, Pleocominae, Aclopinae, Glaphyrinae, Ochodaeinae, Orphninae, Idiostominae, Hybosorinae, Dynamopinae, Acanthocerinae, Troginae.  Coleopterorum Catalogus, 43, 1-66.

Frolov, A.V. (2005) Taxonomic position of Sissantobius mandibularis (Lansberge) and synonymy of Orphnus over Sissantobius (Coleoptera, Scarabaeidae, Orphninae).  Journal of Afrotropical Zoology, 2, 71-73.

Paulian, R. (1948) Revision des Orphnus Africains (Coleoptera, Scarabaeidae).  Annales de la Societe Entomologique de France, 117, 1-75.

Petrovitz, R. (1971) Beitrag zur Kenntnis der Gattung Orphnus M'Leay (Orphninae, Scarabaeidae, Coleoptera).  Revue de Zoologie et Botanique Africaine, 84, 1-46.