Frolov, A.V. 2010. Revision of the Madagascan genus Madecorphnus Paulian (Coleoptera, Scarabaeidae, Orphninae). Journal of Natural History, 44, 1095-1111.

DOI: 10.1080/00222931003632765

Revision of the Madagascan genus Madecorphnus Paulian (Coleoptera, Scarabaeidae, Orphninae)

A.V. Frolov

Laboratory of Insect Systematics, Zoological Institute, Russian Academy of Sciences, Sankt-Petersburg, Russia.

Abstract

A scarab beetle genus, Madecorphnus Paulian, endemic to Madagascar, is revised. Nine new species are described: M. brunneus sp. n., M. dentatus sp. n., M. montreuili sp. n., M. niger sp. n., M. pauliani sp. n., M. perinetensis sp. n., M. peyrierasi sp. n., M. punctatus sp. n., M. simplex sp. n. Diagnosis of the genus is clarified. Distribution map and a diagnostic key to all species are presented.

Key words: scarab beetles, orphnines, new species, Madecorphnus, Madagascar

Introduction

Scarab beetles of the subfamily Orphninae occurring in Madagascar include 4 genera and 21 described species (Paulian, 1937, 1977, 1992; Frolov and Montreuil, 2006, 2009). The genus Madecorphnus Paulian comprises small-sized, dark brown to black, apparently saprophagous beetles which are widely distributed on the island. The first known species of the genus and its type species, M. falciger (Lansberge, 1886), was originally described in the genus Drepanognathus Lansberge, along with D. mandibularis Lansberge (currently Orphnus mandibularis). Since the generic name Drepanognathus was preoccupied, the substitute name Sissantobius Ritsema was used for the two species. The name Madecorphnus was proposed by Paulian (1977) to accommodate M. falciger and S. falculoides Paulian from Madagascar and to separate these two species from African Orphnus mandibularis, the type species of the genus Sissantobius. Synonymy of the names Drepanognathus, Sissantobius, and Madecorphnus is discussed in more detail in Paulian (1992) and Frolov (2005).

Before the present contribution the genus Madecorphnus comprised 3 nominal species: M. falciger, M. falculoides, and M. falcatus Paulian. The two later species were only known from small type series. Most of the collected Madecorphnus specimens were previously identified as M. falciger. The previous workers however did not use characters of the male genitalia, especially parameres and internal sac armature, which are the most reliable diagnostic characters at species level in the Orphninae (unpublished data). After dissecting most of the specimens, I found that more than 10 species can be recognized in this material. This necessitated examination of the type specimens of the described species and revision of the genus.

Madecorphnus specimens are extremely rare in collections. Most probably, population densities of all Madagascan species of the Orphninae are low. Some of the new species are described below from single specimens. I believe however that the descriptions are justified since the differences found cannot be attributed to aberrations, malformations, or interspecific variability of fewer species. The shape of the parameres is very stable at species level in the Orphninae as is the armature of the internal sac of the aedeagus, especially if it consists of a few large sclerites. This was found during examination of reasonable series of different species of the genus Orphnus and some other genera of Orphninae (unpublished data).

The diagnostic key is provided for all species but is suitable for males only. Differentiation of females of closely related species may be difficult or impossible in some cases as in many scarab beetle groups. And, females of some Madecorphnus species are unknown.

Material and methods

The material used for this study is housed at the Muséum National d’Histoire Naturelle, Paris, (MNHN) which, for historical reasons, is the only institution possessing a reasonable number of Madecorphnus specimens at the moment.

To analyze the distribution of the species, a map was generated with ArcGIS software (ESRI, Inc.). As the base map, a Madagascar vegetation map (http://www.vegmad.org) was used. The vegetation map provides a good general representation of the main biomes of Madagascar. Localities were traced using available atlases and a special publication about the main collecting localities in the island (Viette, 1991). Co-ordinates of the localities were taken from the NGA GEOnet Names Server (GNS, http://earth-info.nga.mil/gns/html/index.html). Preparation of genitalia follows the common technique used in entomological research.

Madecorphnus Paulian, 1992

Type species Drepanognathus falciger Lansberge, 1886, designated by Paulian (1977) .

= Drepanognathus Lansberge, 1886, pars.

= Sissantobius Ritsema, 1888: Paulian, 1977, pars.

Diagnosis

Small-sized beetles (4.5–5.0 mm) with mostly uniform, brown to black coloration. Clypeus symmetrical to asymmetrical in males, wide, bordered anteriorly. Mandibles asymmetrical, subequal in length in females and subequal to strongly unequal in males. Head smooth. Frontal tubercles absent. Pronotum wider than long, smooth, lateral margins bordered, with 4–5 long setae. Disc of pronotum similar in both sexes, without any depressions, tubercles, or ridges. Elytra with only first stria distinct. Scutellum triangular, widely rounded apically, about 1/10 length of elytra. Wings fully developed. Parameres symmetrical. Internal sac of aedeagus with 1 or a few sclerites.

The members of Madecorphnus have a number of characters which distinguish the genus from other Orphninae and which are uncommon or unique among the Scarabaeidae. First, the mandibles in males may be highly asymmetrical in both shape and length. In some specimens, the right mandible is twice as long as the left one or even longer. Such specimens also have a clearly asymmetrical clypeus (Figures 1, 3-7). The shape of the mandibles is species specific at least in some species, but it is subject to allometric variability and therefore cannot always be a reliable diagnostic character.

Figures 1-19. Madecorphnus spp. 	 Figures 1-19. Madecorphnus spp. 1 – habitus and scheme of chaetotaxy, 2-7 – head, 8-19 – aedeagus in lateral view and parameres in dorsal view. 1, 9 - M. montreuili sp. n., 2, 12 - M. punctatus sp. n., 3, 8 – M. falculoides, 4, 10 - M. pauliani sp. n., 5, 14 – M. falcatus, 6, 18 - M. perinetensis sp. n., 7, 19 - M. peyrierasi sp. n., 13 - M. dentatus sp. n., 15 - M. simplex sp. n., 16 – M. falciger, 17 - M. brunneus sp. n

Figures 1-19. Madecorphnus spp. 1 – habitus and scheme of chaetotaxy, 2-7 – head, 8-19 – aedeagus in lateral view and parameres in dorsal view. 1, 9 - M. montreuili sp. n., 2, 12 - M. punctatus sp. n., 3, 8 – M. falculoides, 4, 10 - M. pauliani sp. n., 5, 14 – M. falcatus, 6, 18 - M. perinetensis sp. n., 7, 19 - M. peyrierasi sp. n., 13 - M. dentatus sp. n., 15 - M. simplex sp. n., 16 – M. falciger, 17 - M. brunneus sp. n. Scale for figures 8-19.

The second feature, characteristic for the genus, is the presence of a few long setae on the sides of the body and head; the setae have distinct numbers and locations. In general, pubescence of the body is extremely diverse in scarab beetles, ranging from almost absent in some groups to very dense, long, and almost completely hiding sclerites in others. It is subject to some variation within and among species and often differs in the different sexes. Pubescence of the body is widely used in species identification. However, as far as I know, individual homologizable setae, at least on the pronotum and elytra, have not been described in the Scarabaeidae. All the Madecorphnus speciesexcept for two possess the following symmetrically located long setae (Figure 1): 1 seta on elytral base near epipleuron, 1 seta on posterior angle of pronotum, 1 seta approximately in the middle of lateral margin of pronotum, 2 setae on the anterior angle of pronotum, 2 setae on each gena, and 2 setae on the anterior margin of clypeus. As an exception, M. pauliani sp. n. has 3 setae on each anterior angle of pronotum and a female of M. dentatus sp. n. has 2 setae on the hind angle. Even if one or a few these setae are absent, there is no doubt that they were lost as a result of abrasion since in the places where they should be according to the scheme given above, there are characteristic foveae with chaetiferous pores. There are no other setae on the dorsal side of the body except for mouthparts. There are long, relatively sparse setae on epipleura and ventral side of thorax, but they do not have definite locations. Also, often there are small setae on the anterior margin of clypeus.

The third feature that distinguishes Madecorphnus among other Orphninae is a weaker sexual dimorphism. The sexes mostly differ in the shape of the mandibles. Males with relatively feebly developed mandibles are similar to females. In Madecorphnus, the sexual dimorphism character common for all Orphninae genera, namely the absence of distinct anterior tibial spur in males, is less expressed than in other genera. Often, the apical seta is longer and more robust then others and it is similar to the spur. Madecorphnus males also lack any clypeal horns and prothoracic ridges and excavations which are found in majority of species of almost all genera of Orphninae.

Distribution and bionomy

Judging from the known collecting localities (Figure 31), Madecorphnus species are distributed throughout Madagascar but mostly in the eastern part of the island. The notable exception is M. falculoides which was found in the western part. The majority of the localities agree well with current distribution of remnants of indigenous forests. This suggests that forest is the preferred habitat for Madecorphnus. However, collecting might be biased since more insect sampling was done in the forests than in the arid Central and Western Madagascar.

Almost nothing is known about bionomy of Madecorphnus. The labels of the collected specimens lack any data about the way the beetles were collected. It is possible that Madecorphnus species are general saprophagous litter dwellers. They might also be attracted to carrion like Pseudorphnus hiboni Paulian (see Frolov & Montreuil, 2006). Nesting behaviour and preimaginal stages are so far unknown.

Figures 20-30. Madecorphnus spp. 	 Figures 20-30. Madecorphnus spp., schematic representation of invaginated internal sac of aedeagus with armature. 20 - M. falculoides, 21 - M. montreuili sp. n., 22 - M. pauliani sp. n., 23 - M. punctatus sp. n., 24 - M. dentatus sp. n., 25 - M. simplex sp. n., 26 - M. falcatus, 27 - M. falciger, 28 - M. brunneus sp. n., 29 - M. perinetensis sp. n., 30 - M. peyrierasi sp. n.

Figures 20-30. Madecorphnus spp., schematic representation of invaginated internal sac of aedeagus with armature. 20 - M. falculoides, 21 - M. montreuili sp. n., 22 - M. pauliani sp. n., 23 - M. punctatus sp. n., 24 - M. dentatus sp. n., 25 - M. simplex sp. n., 26 - M. falcatus, 27 - M. falciger, 28 - M. brunneus sp. n., 29 - M. perinetensis sp. n., 30 - M. peyrierasi sp. n. Not to scale.

Key to the Madecorphnus species (males)

1. Right mandible with a tooth on inner side of scissorial part (Figures 1, 3)2

- Right mandible without a tooth on inner side of scissorial part (Figures 2, 4, 5)3

2. Parameres slender in dorsal view (Figure 8). Internal sac of aedeagus with 2 large bifurcated sclerites and a few dozen spinules (Figure 20). Mentum without tubercles M. falculoides Paulian

- Parameres wider in dorsal view, with 1 small tooth each (Figure 9). Internal sac of aedeagus with 2 bifurcated sclerites, without smaller spinules (Figure 21). Mentum with 2 tubercles

M. montreuili sp. n.

3. Apices of parameres without lateral teeth (Figures 10, 11) 4

- Apices of parameres with more or less developed lateral teeth (Figures 12-19) 5

4. Parameres without lateral excavations, about 1.5 times longer than basal sclerite of aedeagus (Figure 10) M. pauliani sp. n.

- Parameres with lateral excavations, about 2 times longer than basal sclerite of aedeagus (Figure 11). M. niger sp. n.

5. Head and pronotum with fine dense punctuation. Internal sac of aedeagus with 3 large sclerites and an area with smaller spinules (Figure 23) M. punctatus sp. n.

- Head and pronotum with indistinct to sparse punctuation (punctures separated by at least 3 times their diameter). Internal sac of aedeagus with different armature 6

6. Parameres with large lateral teeth (Figure 13) M. dentatus sp. n.

- Parameres with small lateral teeth (Figure 14-19) 7

7. Internal sac of aedeagus with 1 sclerite composed of 2 long slender spinules connected basally (Figure 25) M. simplex sp. n.

- Internal sac of aedeagus with 2 or more separate sclerites 8

8. Parameres with small teeth at extreme apex (Figure 14, lateral view). Larger (7.0 mm)

M. falcatus Paulian

- Parameres of different shape. Smaller than 6.0 mm. 9

9. Parameres with angulate lateral teeth (Figure 16). Internal sac of the aedeagus with two large semicircular sclerites and 1 long spur-shaped sclerite (Figure 27) M. fasciger (Lansberge)

-. Parameres with small lateral teeth. Internal sac armature different 10

10 Parameres less acute in lateral view (Figure 17). Internal sac of the aedeagus with 1 longer sclerite and one smaller, somewhat bifurcated sclerite (Figure 28) M. brunneus sp. n.

- Parameres more acute in lateral view (Figures 18-19). Internal sac with 2 longer and 2 smaller sclerites (Figures 29, 30) 11

11 Parameres less tapering apically, lateral teeth closer to paramere apices (Figure 18). Eyes somewhat larger (Figure 6) . M. perinetensis sp. n.

- Parameres more tapering apically, lateral teeth not so close to paramere apices (Figure 19). Eyes somewhat smaller (Figure 7) M. peyrierasi sp. n.

Madecorphnus falculoides (Paulian, 1977)

Figures 3, 8, 20, 31.

Type material

Holotype, male: Antsalova, Antsingy, Nature Reserve no 9, I.1975, A. Peyrieras leg. (MNHN). Paratypes: 1 male and 4 females with the same data as the holotype.

Diagnosis

This species is similar to M. montreuili sp. n. in having the right mandible with a tooth on inner side of scissorial part; it differs from it in the shape of the mandibles (Figure 3) and parameres (Figure 8) and in the absence of tubercles on the mentum.

Madecorphnus montreuili Frolov, sp. n.

Figures 1, 9, 21, 31

Type material

Holotype, male: Antanambe, 25.I.1990 (MNHN).

Description

Holotype. Body length 5.8 mm. Colour uniformly dark brown.

Right mandible about 1.5 times longer than left, strongly curved, with a tooth behind apex (Figure 1). Labrum trapezoidal, its length about 1/5 width (in dorsal view).

Clypeus slightly asymmetrical, slightly convex anteriorly, obtuse, with 2 long and a number of smaller setae. Genae very small, not protruding past eyes. Canthus and frontal suture indistinct. Clypeus somewhat depressed in the middle anteriorly, minutely punctate.

Pronotum 1.8 times wider than long, widest medially. Margins with relatively wide border, lateral margins with 4 long setae. Pronotum evenly convex, minutely punctate.

Elytra convex, with distinct humeral and apical calli. Maximum width approximately at basal 1/3. First stria distinct and reaching the apex of elytron, other striae indistinct. Epipleura with long, sparse, brown setae. Base of elytra with border from scutellum to humeral callus. Elytra punctate with sparse relatively large punctures in the middle of each elytron near stria 1.

Anterior tibiae with 3 outer teeth, lateral margin basad of outer teeth not crenulate. Apex with robust, spur-like seta and a few smaller setae basally. Middle and posterior legs similar in shape. Longer tibial spur shorter than two basal tarsomeres in middle legs and shorter than 3 tarsomeres in posterior legs.

Aedeagus. Parameres symmetrical, relatively wide in dorsal view, with 2 distinct teeth laterally (Figure 9). Internal sac with 2 large and 1 smaller sclerites (Figure 21).

Diagnosis

This species differs from other Madecorphnus species in having 2 distinct tubercles on the mentum. It is similar to M. falculoides in having the right mandible with a tooth on inner side of scissorial part but differs from it in the shape of the mandibles and parameres.

Etymology

The species is named after Olivier Montreuil, a scarab beetle specialist at the Natural History Museum, Paris.

Figure 31. Madecorphnus spp.

Figure 31. Madecorphnus spp., distribution map.

Madecorphnus pauliani Frolov, sp. n.

Figures 4, 10, 22, 31

Type material

Holotype, male: Tanala Forest [Fort-Carnot] (MNHN).

Description

Holotype. Body length 5.2 mm. Colour dark brown, head and legs somewhat paler, pronotum with feeble bronze tint.

Right mandible about 2 times longer than left, without tooth behind apex. Labrum trapezoidal, its length 1/4–1/5 width (in dorsal view).

Clypeus asymmetrical, slightly convex anteriorly, obtuse, with 2 long and a number of smaller setae. Genae very small, not protruding past eyes. Canthus and frontal suture indistinct. Clypeus somewhat depressed in the middle anteriorly, minutely punctate.

Pronotum 1.8 times wider than long, widest medially. Margins with relatively wide border, lateral margins with 5 long setae (3 setae located on each anterior angle). Pronotum evenly convex, minutely punctate.

Elytra convex, with distinct humeral and apical calli. Maximum width approximately at basal 1/3. First stria distinct and reaching the apex of elytron, other striae indistinct. Epipleura with long, sparse, brown setae. Base of elytra with border from scutellum to humeral callus. Elytra minutely punctate except for a few relatively large punctures in the middle of each elytron near stria 1.

Anterior tibiae with 3 outer teeth, lateral margin basad of outer teeth not crenulate. Apex with robust, spur-like seta and a few smaller setae basally. Middle and posterior legs similar in shape. Longer tibial spur as long as two basal tarsomeres in middle legs and as long as 3 tarsomeres in posterior legs.

Aedeagus. Parameres widely rounded apically, without lateral teeth (Figure 10). Internal sac with 2 large, feebly sclerotized sclerites (Figure 22).

Diagnosis

This species differs from other Madecorphnus species in having 3 setae on anterior angles of pronotum and in distinct shape of the parameres.

Etymology

The species is named after Renaud Paulian (1913-2003) whose publications provided a sound framework for the taxonomic research on African and Madagascar Orphninae.

Madecorphnus niger Frolov, sp. n.

Figure 11, 31

Type material

Holotype, male: Perinet, A.Peyrieras leg., X.1972. Paratype, male: Perinet, A.Peyrieras leg., X.1973 (MNHN).

Description

Holotype, male. Body length 5.5 mm. Colour black, mouthparts and legs brown.

Right mandible slightly longer than left, without tooth basad of apex. Labrum trapezoidal, its length about 1/4–1/5 width (in dorsal view).

Clypeus asymmetrical, slightly convex anteriorly, obtuse, with 2 long and a number of smaller setae. Genae very small, not protruding past eyes. Canthus and frontal suture indistinct. Clypeus slightly depressed in the middle anteriorly, minutely punctate (punctures separated by more than 10 their diameters).

Pronotum 1.8 times wider than long, widest medially. Margins with relatively wide border, lateral margins with 4 long setae. Pronotum evenly convex, minutely punctate.

Elytra convex, with distinct humeral and apical calli. Maximum width approximately at basal 1/3. First stria distinct and reaching the apex of elytron, other striae indistinct. Epipleura with long, sparse, brown setae. Base of elytra with border from scutellum to humeral callus. Elytra minutely punctate except for a few relatively large punctures in the middle of each elytron near stria 1.

Anterior tibiae with 3 outer teeth, lateral margin basad of outer teeth not crenulate. Apex with robust, spur-like seta and a few smaller setae basally. Middle and posterior legs similar in shape. Longer tibial spur as long as two basal tarsomeres in middle legs and as long as 3 tarsomeres in posterior legs.

Aedeagus. Parameres curved and rounded in lateral view, without teeth but with concavities laterally (Figure 11).

Variation

The paratype differs from the holotype in slightly larger size (body length 5.7 mm), paler coloration, and longer right mandible.

Diagnosis

This species can be separated from other Madecorphnus species by the shape of the parameres and from many species also by darker colour of the body.

Madecorphnus punctatus Frolov, sp. n.

Figures 2, 12, 23, 31

Type material

Holotype, male: E of Lake Mantasoa, Ambohiboatavo, 1340 m, III.1973, P. Griveaud and A. Peyrieras leg. (MNHN). Paratypes, 2 males with the same data as the holotype.

Description

Holotype. Body length 5.0 mm. Head and pronotum dark brown, elytra and legs brown.

Right mandible as long as left, without tooth basad of apex. Labrum trapezoidal, its length about 1/4–1/5 width (in dorsal view).

Clypeus symmetrical, slightly convex anteriorly, obtuse, with 2 long and a number of smaller setae. Genae very small, not protruding past eyes. Canthus and frontal suture indistinct. Clypeus, slightly depressed in the middle anteriorly, rather densely, irregularly punctate (punctures separated by 1-3 their diameters).

Pronotum 1.8 times wider than long, widest medially. Margins with relatively wide border, lateral margins with 4 long setae. Pronotum evenly convex, densely, irregularly punctuate (punctures separated by 1-3 their diameters anteriorly, becoming sparser basally).

Elytra convex, with distinct humeral and apical calli. Maximum width approximately at basal 1/3. First stria distinct and reaching the apex of elytron, other striae indistinct. Epipleura with long, sparse, brown setae. Base of elytra with border from scutellum to humeral callus. Elytra sparsely punctate with relatively large punctures (more densely near suture).

Anterior tibiae with 3 outer teeth, lateral margin basad of outer teeth not crenulate. Apex with robust, spur-like seta and a few smaller setae basally. Middle and posterior legs similar in shape. Longer tibial spur a bit shorter than 2 basal tarsomeres in middle legs and a bit shorter than 3 tarsomeres in posterior legs.

Aedeagus. Parameres tapering apicaly, somewhat arrow-shaped, angulate laterally (Figure 12). Internal sac with 3 large sclerites and an area of short spinules (Figure 23).

Variation

Length of the paratypes varies from 4.5 to 5.0 mm, otherwise they are similar to the holotype.

Diagnosis

This species can be separated from other Madecorphnus species by the densely pubescent head and pronotum and by the shape of the parameres and internal sac armature.

Madecorphnus dentatus Frolov, sp. n.

Figure 13, 24, 31

Type material

Holotype, male: Chaînes Anosyennes, SW of Trafonaomby, plateau Andohahelo, 1770-1950 m, V.1972 (MNHN). Paratype, female with the same data as the holotype. Paratype, male: NW of Fort-Dauphin, massif Andohahelo, forest Andranomangara, Integral Nature Reserve no 11, 1750 m, 20-25.I.1974, A. Peyrieras leg.

Description

Holotype, male. Body length 6.0 mm. Colour reddish brown, head, legs, and apices of elytra somewhat darker.

Right mandible slightly longer than left, without tooth behind of apex. Labrum trapezoidal, its length about 1/4–1/5 width (in dorsal view).

Clypeus asymmetrical, slightly convex anteriorly, obtuse, with 2 long and a number of smaller setae. Genae very small, not protruding past eyes. Canthus and frontal suture indistinct. Clypeus somewhat depressed in the middle anteriorly, sparsely punctate.

Pronotum 1.8 times wider than long, widest medially. Margins with relatively wide border, lateral margins with 4 long setae. Pronotum evenly convex, punctate (punctures separated by 2–3 puncture diameters).

Elytra convex, with distinct humeral and apical calli. Maximum width approximately at basal 1/3. First stria distinct and reaching the apex of elytron, other striae indistinct. Disc of elytra with sparse punctures. Epipleura with long, sparse, brown setae. Base of elytra with border from scutellum to humeral callus. Elytra minutely punctate except for a few relatively large punctures in the middle of each elytron near stria 1.

Anterior tibiae with 3 outer teeth, lateral margin basad of outer teeth not crenulate. Apex with robust, spur-like seta and a few smaller setae basally. Middle and posterior legs similar in shape. Longer tibial spur as long as two basal tarsomeres in middle legs and as long as 3 tarsomeres in posterior legs.

Aedeagus. Parameres symmetrical, tapering apically in lateral view, with large teeth laterally (Figure 13). Internal sac of aedeagus with 1 sclerite composed of 2 long slender spinules connected basally (Figure 24).

Variability

The paratypes are about the same size as the holotype, somewhat paler. Male paratype with shorter mandibles similar to those in female. Female, except for shorter mandibles, differs in having 2 setae on hind angles of pronotum and in robust protibial spur.

Diagnosis

This species can be separated from other Madecorphnus species by distinct shape of parameres and internal sac armature.

Madecorphnus simplex Frolov, sp. n.

Figure 15, 25, 31

Type material

Holotype, male: Ambatofitorahana, 1800 m, 31.XII.1972, A. Peyrieras leg. (MNHN).

Description

Holotype, male. Body length 5.5 mm. Colour reddish brown.

Right mandible 1/5 longer than left, without tooth behind apex. Labrum trapezoidal, its length about 1/4–1/5 width (in dorsal view).

Clypeus asymmetrical, slightly convex anteriorly, obtuse, with 2 long and a number of smaller setae. Genae very small, not protruding past eyes. Canthus and frontal suture indistinct. Clypeus slightly depressed in the middle anteriorly, sparsely punctate (punctures separated by about 5 their diameters).

Pronotum 1.8 times wider than long, widest medially. Margins with relatively wide border, lateral margins with 4 long setae. Pronotum evenly convex, sparsely punctate.

Elytra convex, with distinct humeral and apical calli. Maximum width approximately at basal 1/3. First stria distinct and reaching the apex of elytron, other striae indistinct. Epipleura with long, sparse, brown setae. Base of elytra with border from scutellum to humeral calli. Elytra sparsely punctate except for a few relatively large punctures.

Anterior tibiae with 3 outer teeth, lateral margin basad of outer teeth not crenulate. Apex with robust, spur-like seta and a few smaller setae basally.

Middle and posterior legs similar in shape. Longer tibial spur as long as two basal tarsomeres in middle legs and shorter than 3 tarsomeres in posterior legs. Posterior femora with a few pectinate setae on the inner side apically.

Aedeagus. Parameres rounded apically (in lateral view), with small teeth laterally (Figure 15). Internal sac with 1 long, spur-shaped sclerite and 3 small, tooth-shaped sclerites (Figure 25)

Diagnosis

This species can be separated from other Madecorphnus species by the distinct shape of its parameres and the internal sac armature.

Madecorphnus falcatus Paulian, 1992

Figures 5, 14, 26, 31

Type material

Holotype, male: Antanambe, 25.I.1990 (MNHN).

Diagnosis

This is the largest known species of Madecorphnus: the length of the holotype is a little over 7 mm. Also, it differs from other Madecorphnus speciesin having a distinctive shape of the parameres (Figure 14) and internal sac armature consisting of 2 small bifurcated sclerites, 1 long spur-like sclerite and numerous small spinules (Figure 26).

Madecorphnus falciger (Lansberge, 1886)

Figure 16, 27

Type material

Holotype, male: Madagascar [without exact locality] (MNHN).

Diagnosis

It differs from other Madecorphnus speciesin having characteristic shape of the parameres (Figure 16) and armature of internal sac of the aedeagus consisting of 2 large semicircular sclerites, 1 short spur-like sclerite and numerous small spinules (Figure 27).

Madecorphnus brunneus Frolov, sp. n.

Figure 17, 28, 31

Type material

Holotype, male: East Adringitra Massif, Anjavidilava, 1850-1950 m, 18.XII.1971-15.I.1971 (MNHN).

Description

Holotype. Body length 6.2 mm. Colour brown, pronotum and head dark brown.

Right mandible about 2 times longer than left, without tooth basad of apex. Labrum trapezoidal, its length about 1/5 width (in dorsal view).

Clypeus asymmetrical, slightly convex anteriorly, obtuse, with 2 long setae. Genae very small, not protruding past eyes. Canthus and frontal suture indistinct. Clypeus slightly depressed in the middle anteriorly, finely punctate.

Pronotum 1.9 times wider than long, widest medially. Margins with relatively wide border, lateral margins with 4 long setae. Pronotum evenly convex, minutely punctate.

Elytra convex, with distinct humeral and apical calli. Maximum width approximately at basal 1/3. First stria distinct and reaching the apex of elytron, other striae indistinct. Disc of elytra with sparse punctuation. Epipleura with long, sparse, brown setae. Base of elytra with border from scutellum to humeral callus.

Anterior tibiae with 3 outer teeth, lateral margin basad of outer teeth not crenulate. Apex with robust, spur-like seta and a few smaller setae basally. Middle and posterior legs similar in shape. Longer tibial spur shorter than 2 basal tarsomeres in middle legs and as long as 2 tarsomeres in posterior legs.

Aedeagus. Parameres acutely rounded in lateral view (Figure 17). Internal sac of the aedeagus with 1 longer sclerite and one smaller, somewhat bifurcated sclerite (Figure 28).

Diagnosis

M. brunneus sp. n. is similar to M. perinetensis sp. n. and M. peyrierasi sp. n. but differs from them in having parameres less acute in lateral view and different internal sac armature.

Madecorphnus perinetensis Frolov, sp. n.

Figures 6, 18, 29, 31

Type material

Holotype, male: Perinet, XI.1972, A.Peyrieras leg. (MNHN). Paratypes, 1 male and 2 females with the same data as the holotype. Paratype, male: Perinet, X.1972, A.Peyrieras leg.

Description

Holotype. Body length 5.8 mm. Colour uniformly brown.

Right mandible about 2 times longer than left, without tooth behind apex. Labrum trapezoidal, its length about 1/6 width (in dorsal view).

Clypeus asymmetrical, slightly convex anteriorly, obtuse, with 2 long and 2 shorter setae on the anterior margin. Genae very small, not protruding past eyes. Canthus and frontal suture indistinct. Clypeus slightly depressed in the middle anteriorly, finely punctate.

Pronotum 1.8 times wider than long, widest medially. Margins with relatively wide border, lateral margins with 4 long setae. Pronotum evenly convex, minutely punctate.

Elytra convex, with distinct humeral and apical calli. Maximum width approximately at basal 1/3. First stria distinct and reaching the apex of elytron, other striae indistinct. Disc of elytra with sparsely punctate with relatively large punctures. Epipleura with long, sparse, brown setae. Base of elytra with border from scutellum to humeral callus.

Anterior tibiae with 3 outer teeth, lateral margin basad of outer teeth not crenulate. Apex with robust, spur-like seta and a few smaller setae basally. Middle and posterior legs similar in shape. Longer tibial spur shorter than 2 basal tarsomeres in middle legs and as long as 2 tarsomeres in posterior legs.

Aedeagus. Parameres less tapering apically than in the previous species, wider in dorsal view and acute in lateral view (Figure 18). Internal sac with 2 longer and 2 smaller sclerites (Figure 29).

Variability

Body length of the paratypes is about 5.5 mm. Paratypes have smaller mandibles (right and left almost the same length) and otherwise similar to the holotype.

Diagnosis

This species is similar to M. peyrierasi sp. n. externally and in the shape of internal sac armature, but can be separated from it by different shape of the parameres and somewhat larger eyes (Figure 6).

Etymology

The name of this species is derived from the toponym Perinet, where the type series was collected.

Madecorphnus peyrierasi Frolov, sp. n.

Figures 7, 19, 30, 31

Type material

Holotype, male: Perinet, XI.1972, A.Peyrieras leg. (MNHN). Paratype, female with the same data as the holotype. Paratype, female: Perinet, X.1972, A.Peyrieras leg. Paratype, male: Mandraka, 25.III.1975, A. Peyrieras. Paratype, male: road to Anosibe, 6.IV.1975, A.Peyrieras leg.

Description

Holotype. Body length 6.2 mm. Colour uniformly brown, head a bit darker.

Right mandible about 1.7 times longer than left, without tooth behind apex. Labrum trapezoidal, its length i about 1/6 width (in dorsal view).

Clypeus asymmetrical, slightly convex anteriorly, obtuse, with 2 long and 2 shorter setae on the anterior margin. Genae very small, not protruding past eyes. Canthus and frontal suture indistinct. Clypeus slightly depressed in the middle anteriorly, finely punctate.

Pronotum 1.8 times wider than long, widest medially. Margins with relatively wide border, lateral margins with 4 long setae. Pronotum evenly convex, minutely punctate.

Elytra convex, with distinct humeral and apical calli. Maximum width approximately at basal 1/3. First stria distinct and reaching the apex of elytron, other striae indistinct. Disc of elytra with sparsely punctate with relatively large punctures. Epipleura with long, sparse, brown setae. Base of elytra with border from scutellum to humeral callus.

Anterior tibiae with 3 outer teeth, lateral margin basad of outer teeth not crenulate. Apex with robust, spur-like seta and a few smaller setae basally. Middle and posterior legs similar in shape. Longer tibial spur shorter than 2 basal tarsomeres in middle legs and as long as 2 tarsomeres in posterior legs.

Aedeagus. Parameres tapering apically, acute in lateral view (Figure 19). Internal sac with 2 longer and 2 smaller sclerites (Figure 30).

Variability

Body length of the paratypes from 4.6 to 5.5 mm. Paratypes also differ from the holotype in smaller mandibles.

Diagnosis

This species is similar to M. perinetensis sp. n. externally and in the shape of internal sac armature, but can be separated from it by different shape of the parameres and somewhat smaller eyes (Figure 7).

Etymology

The species is named after A.Peyrieras, who collected many specimens of Madecorphnus including the type series of this species.

Acknowledgments

I am thankful to Olivier Montreuil (MNHN) for the opportunity to work with scarab beetle collection at his institution and for assistance and, Robert Angus (Royal Holloway, University of London) for linguistic corrections and valuable comments on the draft manuscript, and an anonymous reviewer for comments. This work was supported by the Russian Foundation for Basic Research (grant number 07-04-00482-а) and, partly, by European Distributed Institute of Taxonomy (EDIT).

References

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Frolov AV, Montreuil O. 2006. Description of the male of the rare Madagascan species Pseudorphnus hiboni with notes on the genus Pseudorphnus (Coleoptera: Scarabaeidae: Orphninae). Zootaxa 1154:27-33.

Frolov AV, Montreuil O. 2009. A new genus of Orphninae (Coleoptera, Scarabaeidae) from Madagascar. Zoosystematica Rossica 18:65-69.

Paulian R. 1937. Faune entomologique de Madagascar. Coleoptera Lamellicornia, Scarabaeidae Acanthocerini, Trogini, Aulonocnemis, Hybosorini, Orphnini et Ochodaeini. Bulletin de l'Académie malgache (nouvelle série) 19:129-143.

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Paulian R. 1992. Un nouveau genre et une nouvelle espèce d'Orphnidae de Madagascar (Coleoptera, Scarabaeoidea). Revue Française d'Entomologie (N.S.) 14:169-171.

Viette P. 1991. Chief field stations where Insects were collected in Madagascar. Paris: Privately published by the author.