Madaglymbus menalamba, Ranarilalatiana, Tolotra & Bergsten, Johannes, 2019

Ranarilalatiana, Tolotra & Bergsten, Johannes, 2019, Discovery of a specialist Copelatinae fauna on Madagascar: highly ephemeral tropical forest floor depressions as an overlooked habitat for diving beetles (Coleoptera, Dytiscidae), ZooKeys 871, pp. 89-118 : 102-106

Madaglymbus menalamba sp. nov. Figs 1F , 3C , 12 , Suppl. material 1: Movie 1

Type locality.

Nosy Mangabe Special Reserve, part of Masoala National Park [15.4845S, 49.7627E] (Madagascar, Analanjirofo region, Maroantsetra)

Type material.

Holotype ♂ GP (NHRS): // NHRS-JLKB | 000066360 // Madagascar:Toamasina:Analanjirofo: | Nosy Mangabe, Masoala NP: MAD18-63 | flat dry pansections of path btw camp | and Plage Hollandaise, lowalt. rainforest | 15.4845 S, 49.7627E, 50 m, 20.II.2018 | Leg. J. Bergsten & T. Ranarilalatiana // Holotype | Madaglymbus menalamba sp. nov. | Det. Ranarilalatiana | & Bergsten, 2019 //

Paratypes: -4♂ GP, 2♀ (NHRS): // NHRS-JLKB | 000066010, 66307-11 // Madagascar: Toamasina: Analanjirofo: | Masoala NP: lowalt. rainforest | MAD18-45: small muddy depression | on path ~2 km NE. of Andranobe camp | 15.6703S, 49.9715E, 360 m, 16.II.2018 | Leg. J. Bergsten & T. Ranarilalatiana // Paratype | Madaglymbus menalamba sp. nov. | Det. Ranarilalatiana | & Bergsten, 2019 //

-4♂ GP, 10♀ (NHRS, DEUA & PBZT/MBC): // NHRS-JLKB | 000065792, 65794, 66009, 66314-24 // Madagascar: Toamasina: Analanjirofo: | Masoala NP: lowalt. rainforest | MAD18-49: small muddy depression | on path ~2 km NE. of Andranobe camp | 15.6703S, 49.9715E, 360 m, 18.II.2018 | Leg. J. Bergsten & T. Ranarilalatiana // Paratype | Madaglymbus menalamba sp. nov. | Det. Ranarilalatiana | & Bergsten, 2019 //

-1♂, 2♀ (NHRS): // NHRS-JLKB | 000066011-3 // Madagascar: Toamasina: Analanjirofo: | Masoala NP: lowalt. rainforest | MAD18-51: depression on forest floor on | path ~1.2 km NE of Andranobe camp, | 15.6735S, 49.9647E, 230 m, 18.II.2018 | Leg. J. Bergsten & T. Ranarilalatiana // Paratype | Madaglymbus menalamba sp. nov. | Det. Ranarilalatiana | & Bergsten, 2019 //

-3♂ GP, 2♀ (NHRS): // NHRS-JLKB | 000010814, 65791, 65793, 66012, 66293 // Madagascar: Toamasina: Analanjirofo: | Nosy Mangabe, Masoala NP: MAD18-57 | flat dry pansections of path after | lighthouse, lowalt. rainforest | 15.5078S, 49.7637E, 210 m, 19.II.2018 | Leg. J. Bergsten & T. Ranarilalatiana // Paratype | Madaglymbus menalamba sp. nov. | Det. Ranarilalatiana | & Bergsten, 2019 //

-1♂, 1♀ (NHRS): // NHRS-JLKB | 000066013, 66292 //Madagascar: Toamasina: Analanjirofo: | Nosy Mangabe, Masoala NP: MAD18-58 | rainfallpool with dead leaves nr path | after lighthouse, lowalt. rainforest | 15.5079S, 49.7641E, 195 m, 19.II.2018 | Leg. J. Bergsten & T. Ranarilalatiana // Paratype | Madaglymbus menalamba sp. nov. | Det. Ranarilalatiana | & Bergsten, 2019 //

-3♂, 2♀, 14 ex. (6♂, 8♀) (Alc.) (NHRS, DEUA & PBZT/MBC): // NHRS-JLKB | 000066356-9, 66361, 66014(Alc.) // Madagascar: Toamasina: Analanjirofo: | Nosy Mangabe, Masoala NP: MAD18-63 | flat dry pansections of path btw camp | and Plage Hollandaise, lowalt. rainforest | 15.4845S, 49.7627E, 50 m, 20.II.2018 | Leg. J. Bergsten & T. Ranarilalatiana // Paratype | Madaglymbus menalamba sp. nov. | Det. Ranarilalatiana | & Bergsten, 2019 //

Diagnosis.

A small and robust reddish Madaglymbus species similar to M. kelimaso , but less elongate and elytra concolorous with pronotum and covered with large punctures instead of subrugosity ( Fig. 1F ). Penis short and robust in ventral view with upturned apex in lateral view ( Fig. 3C ).

Description.

Body length: 3.7-4.5 mm (♀: 3.7-4.3 mm, ♂: 3.8-4.5 mm).

Body shape subparallell, robust and rather convex anteriorly. A broader body shape compared with M. kelimaso sp. nov. Lateral outline non-continuous between pronotum and elytra. Head broad with small eyes creating a wide interocular distance ( Fig. 1F ).

Body with a rather uniform reddish coloration, only head partly infuscated between eyes. All appendages testaceous except metatarsus rufotestaceous.

Elytra and pronotum densely covered with large punctures, puncturation reduced posteriorly and towards lateral margins of elytra. Pronotum with a narrow lateral bead not reaching anterior corners. Head covered with finer punctation. Head, pronotum and elytra with same type of microreticulation and micropunctures.

Ventral side entirely testaceous, metacoxal lines absent, suggestion of ridge in their place less distinct compared with M. kelimaso sp. nov., metacoxal plate and abdominal sternites II–IV with fine strioles. Anterior metaventral process broader than in M. kelimaso sp. nov.

Male pro and mesotarsal segments I–III dilated and ventrally equipped with adhesive discs (constellation I:3, 4, II:4, III:4). Segments less dilated than in M. kelimaso and first row with fewer discs. Anterodistal angle of protarsal segment IV with a modified stout seta.

Bilobed penis short and robust with rather blunt apex in ventral view. Ventral lobe twisted around right side of dorsal lobe to a position dorsal of it at apex ( Fig. 3C ). Apex in lateral view upturned. Parameres with apical extension not as long and thin as in M. kelimaso sp. nov. ( Fig. 3C ).

Female with similar dorsal puncturation as in male.

Distribution.

Masoala NP including the island of Nosy Mangabe ( Fig. 4C ).

Ecology and conservation.

The species was found in humid forests at low-altitude between (50-360 m) in dry shallow forest floor depression with dead leaves and soil. In one out of five localities it was collected from a rainwater-filled pit full of dead leaves, the other four places from dry forest floor depressions ( Figs 7 - 10 ). Although less pristine and with clear signs of former human settlements, an equal number of specimens were found on Nosy Mangabe Island as compared with Masoala NP proper near Andranobe.

Etymology.

Menalamba in Malagasy means red clothes and the word is associated with the revolt and anti-colonianism movement in Madagascar’s history of independence. Here it refers to the characteristic reddish coloration of the species ( Fig. 12 , Suppl. material 1: Movie 1).

Notes.

At one locality on Nosy Mangabe (MAD18-57) we videorecorded the terrestrial locomotion and behaviour of this species in the field (Suppl. material 1: Movie 1). It was clearly apt at running and its immediate behaviour following exposure from, e.g. lifting up a dead leaf under which it was hiding, was to run and seek shelter again. This was repeated many times making it difficult to get photos of the species. The Copelatus species had a greater tendency to jump when exposed among the litter, but M. menalamba sp. nov. stayed put initially and then moved by running.

Figures

Figure 1. Habitus, dorsal view. A Copelatus amphibius sp. nov. (female) B Copelatus zanatanensis sp. nov. (female) C Copelatus betampona sp. nov. (female) D Madaglymbus semifactus sp. nov. (female) E Madaglymbus kelimaso sp. nov. (male) F Madaglymbus menalamba sp. nov. (female).

Figure 3. Male genitalia. From left to right aedeagus in right lateral, ventral, left lateral views, and left paramere. A Madaglymbus semifactus sp. nov. B Madaglymbus kelimaso sp. nov. C Madaglymbus menalamba sp. nov.

Figure 4. Maps of Madagascar with species distributions and administrative divisions. A Copelatus amphibius sp. nov. (circle), Copelatus betampona sp. nov. (square) B Copelatus zanatanensis sp. nov. (circle), Madaglymbus semifactus sp. nov. (square) C Madaglymbus kelimaso sp. nov. (circle), Madaglymbus menalamba sp. nov. (square) D current 22 regions and six former provinces of Madagascar.

Figure 7. Habitat photos of locality MAD 18 - 45, Masoala NP. The two new species Copelatus zanatanensis sp. nov. and Madaglymbus menalamba sp. nov. were found in this habitat.

Figure 10. Habitat photo of locality MAD 18 - 57, Nosy Mangabe, near where Madaglymbus menalamba sp. nov. was photographed and video-recorded.

Figure 12. Madaglymbus menalamba sp. nov. photographed in the field on Nosy Mangabe (MAD 18 - 57). Note the very distinctly reddish colour, not known from any previously described Madaglymbus species. See also Suppl. material 1: Movie 1 for recordings of the terrestrial locomotion (running) and behaviour of the species.