Frolov, A.V. 2012. Three new species of scarab beetle genus Madecorphnus Paulian, 1992 (Coleoptera: Scarabaeidae: Orphninae) from Madagascar. Proceedings of the Zoological Institute RAS, 316, 159–165.

Three new species of scarab beetle genus Madecorphnus (Coleoptera: Scarabaeidae: Orphninae) from Madagascar

A.V. Frolov

Zoological Institute of the Russian Academy of Sciences, Universitetskaya Emb. 1, 199034 Saint Petersburg, Russia; e-mail: afrolov@zin.ru

Abstract

Three new species of the scarab beetle genus Madecorphnus Paulian, 1992, endemic to Madagascar, are described and their characters are illustrated. The new species are: M. hanskii sp. n. (Ambohitantely special reserve, central plateau), M. aquilonius sp. n. (Northern Madagascar), and M. barclayi sp. n. (Masoala Peninsula, North-Eastern Madagascar). Distribution maps are presented.

Key words: scarab beetles, orphnines, Madagascar

ТРИ НОВЫХ ВИДА ПЛАСТИНЧАТОУСЫХ ЖУКОВ РОДА MADECORPHNUS (COLEOPTERA: SCARABAEIDAE: ORPHNINAE) ИЗ МАДАГАСКАРА

А. В. Фролов

Зоологический институт Российской академии наук, Университетская наб. 1, 199034 Санкт-Петербург, Россия; e-mail: afrolov@zin.ru

РЕЗЮМЕ

В статье описаны и проиллюстрированы три новых вида пластинчатоусых жуков эндемичного для Мадагаскара рода Madecorphnus Paulian, 1992: M. hanskii sp. n. (заповедник Амбохитантели), M. aquilonius sp. n. (Северный Мадагаскар), и M. barclayi sp. n. (полуостров Масоала, Северо-Восточный Мадагаскар). Представлены карты распространения видов.

Ключевые слова: пластинчатоусые жуки, орфнины, Мадагаскар

Submitted March 23, 2012; accepted May 25, 2012.

Inroduction

Madecorphnus Paulian, 1992, is a peculiar genus of the Madagascan scarab beetles. Members of this genus are characterized by strongly asymmetrical mandibles in some males (Paulian, 1992) as well as by the head and pronotum chaetotaxy which is not found in other scarab beetles (Frolov, 2010a). After the revision of the genus was published (Frolov, 2010a) I was given an opportunity to examine additional material which was not available previously. In this material, I found specimens that belong to 3 distinct species that cannot be classed as any of the described ones. In the present paper these new species are described and their characters are illustrated. The distribution maps are also presented for each species.

Abbreviations of organizations. BMNH, Natural History Museum (London, UK); CASSF, California Academy of Sciences (San Francisco, USA); ZIN, Zoological Institute of the Russian Academy of Sciences (Saint Petersburg, Russia).

Material and methods

Preparation of genitalia follows the common technique used in entomological research. Photographs of the habiti and parameres were taken with a Leica MZ9.5 stereo microscope from dry specimens. Partially focused serial images were combined in Helicon Focus software to produce completely focused images. Photographs of the internal sac armatures were taken with the same microscope from specimens in glycerol. Photographs were not altered except for digital enhancing with Adobe Photoshop (levels and tone correction, background elimination, sharpening). To analyze the distribution of the species, maps were generated with ArcGIS software. 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. Co-ordinates of the localities were taken from the specimen labels, if available, or traced using literature (Thorstrom and Watson, 1997).

Systematics

Family Scarabaeidae Latreille, 1802
Subfamily Orphninae Erichson, 1847
Genus Madecorphnus Paulian, 1992

Madecorphnus hanskii Frolov, sp. n.
(Fig. 1–6)

Madecorphnus hanskii

Figs 1–6. Madecorphnus hanskii sp. n, holotype, male. 1 – habitus, 2 – parameres in dorsal and lateral view, 3 – labels, 4 – invaginated internal sac of aedeagus, 5 – schematic representation of armature of invaginated internal sac, 6 – distribution map and a legend to vegetation types.

Holotype. Male: Madagascar, Ambohitantely [18°10' S, 47°17' E], 24.3.2005, wet forest, I. Hansky group leg. (ZIN).

Etymology. The new species is named after Prof. Ilkka Hanski (Helsinki), who collected the type specimen.

Differential diagnosis. M. hanskii sp. n is similar to M. falciger (Lansberge, 1886) and M. punctatus Frolov, 2010, in having internal sac of aedeagus armed with 3 sclerites: 1 relatively long, spur-like, and 2 comma-shaped or somewhat bifurcated (Fig. 4, 5). It can be separated from these species by the shape and relative size of these sclerites and, from the latter, by the shape of parameres and sparse punctation of head and pronotum (cf. Frolov 2010: Figs 12, 16, 23, and 27).

Description. Holotype, male (Fig. 1, 2, 4, 5). Body length 5.3 mm. Color uniformly brown.
Right mandible as long as left, without tooth behind apex. Labrum trapezoidal, with broadly rounded sides, length about 1/6 width (in dorsal view). Clypeus very slightly asymmetrical, apically obtuse, with 2 long and 6 shorter setae on the apical margin. Genae very small, not protruding past eyes. Canthus and frontal suture absent. Clypeus almost flat, minutely depressed apicomedially. Head without traces of frontoclypeal suture, finely punctate with minute punctures separated by greater than 5 times their diameter.

Pronotum approximately 1.6 times wider than long, widest medially. Disc of pronotum convex, without any depressions, tubercles, or ridges. Punctation on pronotum similar to that on head. Margins with relatively wide border, lateral margins with 4 long setae: 1 seta on basal angle, 1 seta approximately in the middle of lateral margin, and 2 setae on the apical angle.
Scutellum triangular, right angled apically, about 1/13 length of elytra.

Elytra convex, with distinct humeral calli, widest at basal third, glabrous. First stria distinct and reaching the apex of elytron, other striae indistinct. Disc of elytra with a few relatively large punctures. Epipleura with long, sparse, brown setae. Base of elytron with border. Wings fully developed.

Protibiae with 3 outer teeth, lateral margin basad of outer teeth not crenulate. Protibial apex with robust, spur-like seta and 2 smaller setae basally. Middle and posterior legs similar in shape to each other, posterior legs somewhat longer. Longer tibial spur shorter than 2 basal tarsomeres in middle legs and longer than 2 basal tarsomeres in posterior legs.

Parameres with teeth laterally, narrowly rounded apically in dorsal view and curved downwards in lateral view (Fig. 2). Internal sac with a long spur-like sclerite and 2 smaller somewhat comma-shaped sclerites (Fig. 4, 5).

Female unknown.

Distribution and habitat. The type specimen of M. hanskii sp. n. was collected in wet forest in Ambohitantely special reserve. The reserve is situated at altitudes of about 1500 m a. s. l. and houses last remnants of forest on the central plateau of Madagascar. M. hanskii sp. n. is apparently a forest litter dweller and, due to severe deforestation of the central plateau, its current range may be limited to this small forest remnant (Fig. 6).

Madecorphnus aquilonius Frolov, sp. n.
(Fig. 7–12)

Madecorphnus aquilonius

Fig. 7–12. Madecorphnus aquilonius Frolov, sp. n, holotype, male. 7 – habitus, 8 – parameres in dorsal and lateral view, 9 – labels, 10 – invaginated internal sac of aedeagus, 11 – schematic representation of armature of invaginated internal sac, 12 – distribution map.

Holotype. Male: Madagascar, Province Diego-Suarez, Sakalava Beach, dwarf littoral forest, elevation 10 m, 13-16 May 2001 / 12 15'46''S 49 23'51'' E R.Harin'Hala coll. malaise trap — across sandy trail MA-01-04B-09/ CASENT 8014036 (CASSF).

Etymology. The new species epithet is a Latin word meaning “northern”.

Differential diagnosis. From other Madecorphnus species M. aquilonius sp. n. can easily be separated by having characteristic internal sac armature consisting of 2 rather large sclerites: a spur-like one and an asymmetrical, claw-shaped one (Fig. 10, 11).

Description. Holotype, male (Fig. 7, 8, 10, 11). Body length 5.8 mm. Color uniformly brown.
Right mandible about 1/2 longer than left, without tooth behind apex. Labrum trapezoidal, with rounded sides, length about 1/6 width (in dorsal view). Clypeus distinctly asymmetrical, apically obtuse, with 4 relatively long setae on the apical margin. Genae very small, not protruding past eyes. Canthus and frontal suture indistinct. Clypeus slightly depressed apicomedially. Head without traces of frontoclypeal suture, finely punctate with minute punctures separated by greater than 4 times their diameter.

Pronotum approximately 1.75 times wider than long, widest medially. Disc of pronotum convex, without any depressions, tubercles, or ridges. Punctuation on pronotum as fine as that on head. Margins with relatively wide border, lateral margins with 4 long setae: 1 seta on basal angle, 1 seta approximately in the middle of lateral margin, and 2 setae on the apical angle.
Scutellum triangular, angulate apically, about 1/11 length of elytra.

Elytra convex, with distinct humeral calli, widest at basal third. First stria distinct and reaching the apex of elytron, other striae indistinct. Disc of elytra sparsely punctate with relatively large punctures. Epipleura with long, sparse, brown setae. Base of elytron with border connected to first elytral stria. Wings fully developed.

Protibiae with 3 outer teeth, lateral margin basad of outer teeth not crenulate. Apex with robust, spur-like seta and 2 smaller setae basally. Middle and posterior legs similar in shape to each other, posterior legs 1.4 times longer than middle. Longer tibial spur as long as 2 basal tarsomeres in middle legs and longer than 2 tarsomeres in posterior legs.

Parameres with small teeth laterally, narrowly rounded apically in dorsal view and curved downwards in lateral view (Fig. 8). Internal sac with 2 rather large sclerites: a spur-like one and an asymmetrical, claw-shaped one (Fig. 10, 11).

Female unknown.

Distribution and habitat. This species is known from the only locality in northernmost Madagascar. This locality is some 40 km NE of the locality of M. cuccodoroi Frolov, 2010, but, more interestingly, the new species occurs in sandy littoral forest of the Madagascar dry deciduous forest eco-region while the latter species was found in humid forest of Amber Mountain (Frolov, 2010b).

Madecorphnus barclayi Frolov, sp. n.
(Fig. 13–19)

Madecorphnus barclayi

Figs 13–19. Madecorphnus barclayi sp. n, holotype, male. 13 – habitus, 14 – parameres in dorsal and lateral view, 15 – labels, 16 – invaginated internal sac of aedeagus, 17 – schematic representation of armature of invaginated internal sac, 18 – head in dorsal view (tubercles on mentum arrowed), 19 – distribution map.

Holotype. Male: Madagascar, E. Masoala, 50–470 m, R. Antsamanarana, 3-7.XII.1993, Flight Intercept Trap, 1994-138 (BMNH).

Paratypes. Two specimens with the same locality label as the holotype, male (ZIN) and female (BMNH).

Etymology. The new species is named after Maxwell Barclay, curator of Coleoptera collection of BMNH.

Differential diagnosis. This species is similar to M. montreuili Frolov, 2010, in having 2 distinct tubercles on the mentum (Fig. 18) and bidentate apex of right mandible (Fig. 13), but differs from it in having internal sac of aedeagus with two slender bifurcate sclerites (Fig. 16, 17) as opposed to having 3 conical to spur-shaped sclerites in the latter species (cf. Frolov 2010: Fig. 21). All type specimens of M. barclayi sp. n. are uniformly castaneous while all specimens of M. montreuili are colored dark brown to black. The body coloration however may not be as diagnostically reliable character as the internal sac armature.

Description. Holotype, male (Fig. 13, 14, 16–18). Body length 6.0 mm. Color uniformly castaneous, elytra somewhat paler. Right mandible about 1.5 times longer than left, strongly curved, with a tooth behind apex (Fig. 13). Labrum trapezoidal, with rounded anterior angles, its length about 1/5 width (in dorsal view). Mentum with 2 conical tubercles (Fig. 18).
Clypeus slightly asymmetrical, almost flat anteriorly, obtuse, with 1 long and a few smaller setae. Genae almost indistinct. Canthus and frontal suture absent. Head dorsally with minute punctures separated by more than 5 puncture diameters.

Pronotum 1.5 times wider than long, widest medially. Margins with relatively wide border, lateral margins with 4 long setae. Punctuation on pronotum similar to that on head.
Elytra convex, with distinct humeral 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 connected to first elytral interval. Elytra punctate with sparse relatively large punctures on disc.

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, posterior legs 1.3 times longer than middle. Longer tibial spur shorter than two basal tarsomeres in middle legs and almost as long as 3 tarsomeres in posterior legs.

Aedeagus. Parameres symmetrical, relatively wide in dorsal view, with 2 distinct teeth laterally (Fig. 14). Internal sac with 2 slender bifurcated sclerites (Fig. 16, 17).

Paratypes. Body length 5.6 mm (male) and 5.5 mm (female). Apart from body length the male paratype is very similar to the holotype. Female differs from males in having short mandibles and long protibial spur. Female paratype is damaged and lacking right elytron.

Distribution and habitat. Madecorphnus barclayi sp. n. is known from one locality in northern part of the Masoala Peninsula. It is the only species of the genus recorded from the Peninsula so far. The Masoala Peninsula is one of the largest forest blocks in Madagascar and a top conservation priority due to its lowland humid forests, now rare elsewhere in Madagascar (Du Puy and Moat, 1996; Kremen et al., 1999).

Acknowledgements

The author is thankful to I. Hanski for donating material to the ZIN collection, and Maxwell Barclay (BMNH) and Jere Schweikert (CASSF) for loans of the Madecorphnus specimens. This work was supported by the Russian Foundation for Basic Research (grant 10-04-00539-a) and Ministry of Education and Science of Russian Federation (contract 16.518.11.7070).

References

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