Schizodontus mahimborondroensis, Bouyer & Drumont & Roland & Slootmaekers & Pirkl & Jocque, 2021

Bouyer, Thierry, Drumont, Alain, Roland, Lily-Arison Rene De, Slootmaekers, Dan, Pirkl, Jiri & Jocque, Merlijn, 2021, Notes on a small collection of Prioninae from North-East Madagascar with the description of a new Schizodontus Quentin & Villiers, 1974 (Cerambycidae Closterini), Zootaxa 4964 (1), pp. 188-194 : 191-193

Schizodontus mahimborondroensis sp. nov. Bouyer & Drumont

( Figs 2 , 5–7 , 8 (1))

Type material. Holotype male and 2 paratypes male: Madagascar, Bemanevika , 1717 m, 14.2939 S- 48.7569 E, 8.II.2019, light trap, [ MAD19 RIDGE LT]. BINCO _ MAD _19_0008, Leg. Merlijn Jocque & Dan Slootmaekers, in coll. RBINS (HT and 1 PT), and coll. Th. Bouyer (1 PT).

Description.

Holotype male ( Fig. 2 ). Head and thorax. Head, pronotum and scutellum ( Fig. 5 ) strongly punctuate and covered with a dense mat of small hairs. Interocular space flat, with a well-defined median groove between base of antenna. A shallow transversal supramandibular groove clearly present. Antennae long, reaching just before or just about end of elytra.Antennomeres relatively wide, with an external apical tooth clearly visible from antennomere III onwards, antennomere VII with an internal apical tooth but always much smaller than external apical tooth, antennomeres X–XI almost completely merged ( Fig. 7 ).

Lateral pronotal spines medium to small, central spines almost equal in size to anterior spines. Prosternum clearly and densely setose. Pronotum with a well-defined medial notch in posterior ridge behind head. No local depression in pronotum.

Abdomen and elytra. General color dark brown. Elytra covered with a short, sparse and barely visible mat of fine hairs, providing shiny elytra, especially at level of disc. Elytra finely punctuated with well-defined longitudinal ridges ( Fig. 6 ).

Female. Unknown

Dimensions. Holotype is 34 mm ( Fig. 2 ). Range length for three male specimens collected is 29–34 mm. Pronotum length: 3.5–4.5 mm. Pronotum maximal width without spines: 6.5–7.5 mm.

Etymology. The species is named after the Malagasy name for the type locality: Mahimborondro, meaning “a place to feel the clouds” and refers to the cloud forest habitat of the species.

Ecology. Nothing is known about the ecology of the species at this point, but the specimens were collected in dense high elevation ridge clad in montane forest ( Fig. 9 ).

Similar species. There are only three described species in the genus. Holotypes of S. latus and S. angustus are preserved in MNHN (Figs 3–4) and high resolution images of these two species are available through the website of the Prioninae (http://www. prioninae .eu/) managed by one of the authors (Pirkl). Males of the three species can most easily be separated based on the structure of the antennae ( Fig. 8 ). Additionally, S. latus has a smooth posterior pronotum, while both S. angustus and S. mahimborondroensis sp. nov. have a small well-defined medial notch in the posterior pronotum edge. Also, the colouration and brightness of the elytra differs between the species with S. mahimborondroensis sp. nov. dark brown compared to reddish brown in S. latus (Fig. 4) and its elytra are more reflecting compared to both other species.

The three Schizodontus species can be identified with the following dichotomous key.

1 - Antennae with narrow articles (ratio length / width for antennomere III: 2.9); antennomere III with subparallel sides and without tooth at apical angles ( Fig. 8 )............................................. S. angustus Quentin & Villiers, 1974

- Antennae with wide articles (ratio length / width for antennomere 3: 2.1–2.4), antennomere III widened anteriorly with a small well defined apical external tooth ( Fig. 8 ).................................................................. 2

2 - Prominent external apical tooth present only on antennomeres V or VI, anterior pronotum ridge smooth and uninterrupted, reddish brown elytra............................................................. S. latus Quentin & Villiers, 1974

- Prominent external apical tooth on antennomere III, anterior pronotum ridge centrally with a small notch, dark brown elytra........................................................................... S. mahimborondroensis sp. nov.

Figures

FIGURE 2. Schizodontus mahimborondroensis sp. nov. Holotype male, 34 mm, dorsal view (RBINS). Figure 3. Schizodontus angustus Quentin & Villiers, 1974. Holotype male, 34 mm, dorsal view (MNHN). Figure 4. Schizodontus latus Quentin & Villiers, 1974. Holotype male, 37 mm, dorsal view (MNHN). (Photos Thierry Bouyer (Fig. 2) & Jiri Pirkl (figs 3–4)).

FIGURE 8. First antennal segments of 1) Schizodontus mahimborondroensis sp. nov. (male), 2) S. latus (male), 3) S. angustus (male) and 4) S. latus (female). 2–4 after Quentin & Villiers, 1975, figs. 227–229.

FIGURE 9. Montane ridge forest where Schizodontus mahimborondroensis sp. nov. was collected (Photo Merlijn Jocque).

FIGURES 5–7. Schizodontus mahimborondroensis sp. nov. Male holotype (34 mm). Fig. 5: holotype, head and pronotum, dorsal view. Fig. 6: elytra, lateral view from the left side. Fig. 7: left antenna with numbered articles (Photos Thierry Bouyer).