Madastiger Hlaváč & Baňař, 2017

Baňař, Petr, 2017, The Pselaphinae (Coleoptera: Staphylinidae) of Madagascar. VII. Description of Madastiger robustus gen. and sp. nov. from Central Madagascar, Zootaxa 4311 (3), pp. 435-440 : 436

Madastiger Hlaváč & Baňař gen. nov.

( Figs. 1–11 )

Type species: Madastiger robustus sp. nov. Present designation.

Diagnosis. Body length 1.58 mm; head pentagonal, slightly tapered anteriad, rostrum triangular, head clearly narrower than pronotum, head with laterally located vertexal foveae, frontal fovea absent, pronotum with antebasal foveae, elongate median sulcus, and lateral foveae; antennae with 4 antennomeres, terminal antennomere cylindrical, truncate at apex; elytra with 2–3 evanescent foveae, with very weakly defined elytral striae, lacking trichomes; abdomen slightly shorter than elytra, composite tergite (IV–VI) with transverse impression and trichomes, both hidden under elytra.

Description. Body ( Fig. 1 ) uniformly reddish-brown, sparsely covered with very short appressed, posteriorly directed setae, head coarsely punctured, pronotum and elytra with some discal coarse punctures, body length 1.58 mm, maximum width at posterior corners of elytra 0.80 mm. Head ( Fig. 2 ) slightly shorter than wide, widest across eyes, evenly tapered anteriad, rostrum anteriorly triangular, with well-defined lateral vertexal foveae. Antennae ( Fig. 5 ) with four antennomeres, about as long as head, partly hidden in antennal cavity; scapes minuscule, not visible dorsally, pedicels much larger than scapes and larger than antennomeres III, terminal antenomeres short, at apex truncate, with stout dense setae, more than 4 times as long as antennomere III. Pronotum slightly wider than long and slightly longer than head, widest at level of projected posterior corners; antebasal fovea, elongate median sulcus, and lateral foveae present. Elytra ( Fig. 4 ) robust, wider than long, with 2–3 evanescent basal foveae, with 4 rows of uneven coarse punctures, lacking trichomes. Abdomen ( Figs. 3 , 6, 7 ) short, slightly narrower than elytra, composite tergite with basal, heavily sclerotized impression and robust lateral trichomes ( Fig. 6 ), with both hidden under elytra in undissected specimen, first three visible paratergites well-developed, paratergites I with minute trichomes ( Fig. 6 ). First visible sternite ( Fig. 7 ) slightly shorter than second (IV), second with well-defined basolateral foveae ( Fig. 7 , blf), slightly longer than third visible sternite (V), third (V) and fourth (VI) visible sternites subequal in length.

Legs short and stout, tibiae about as long as femora, mesotibiae with preapical spurs, metatibiae curved before apex.

Aedeagus ( Figs. 8–11 ) symmetrical, parameres fused to median lobe, basal bulb about as long as apical lobe, which is tapered to apex, diaphragm opening large, oval. Apex of apical lobe with pair of accessory lobes bearing dense fringe of long setae ( Fig. 9 , 11 ). Proximal two-thirds of inflated endophallus bare, distal third with heavily sclerotized teeth ( Fig. 8 ).

Sexual dimorphism. Female unknown but most probably lacking preapical spur on mesotibiae.

Differential diagnosis: Madastiger is tentatively assigned to the subtribe Mastigerina, although it disagrees with certain character states that have been used to define Mastigerina ( Hlaváč, 2011). The following character states should be withdraw from the subtribal diagnosis of Mastigerina: the lateral antennal cavities cover only small, basal part of the antennae (also found in some undescribed Mastiger ) thus antennae are well-visible dorsally; humeri are not carinate, and mesotibiae are not flat. Madastiger is placed near Tasmiger and Mastiger , which both have the terminal antennomeres truncate at their apices. The new genus is readily separated from Mastiger , which has antennae with 3 antennomeres, and from Tasmiger by the absence of trichomes on the posterior margin of the elytra as well as the foveation pattern of head and as well as the foveation pattern of pronotum, and by the very remarkable structure of the aedeagus (presence of accessory lobes on its apex), which is unique in the tribe Clavigerini .

Etymology. The new generic name, Madastiger is a combination composed from “ Mada ” meaning Madagascar and suffix “ stiger ” from Mastigerina. Gender masculine.

Distribution. Central Madagascar.

Figures

FIGURES 1 – 5. Madastiger robustus gen. et sp. nov. Hlaváč & Baňař, male holotype. 1, dorsal habitus; 2, head, dorsal view; 3, abdomen, dorsal view; 4, left elytron, dorsal view; 5, right antenna, latero-dorsal view. Scale bars in mm.

FIGURES 6 – 9. Madastiger robustus gen. et sp. nov. Hlaváč & Baňař, male holotype. 6, abdomen, dorsal view; 7, abdomen, ventral view; 8, inflated aedeagus, lateral view; 9, accessory lobes with long setae, apical view. Lettering: blf = basilateral fovea; pt I, II, III = paratergite I, II, III. Scale bars in mm, accessory lobes (Fig. 9) not measured in this view.

FIGURES 10 – 11. Madastiger robustus gen. et sp. nov. Hlaváč & Baňař, male holotype. 10, aedeagus, ventral view; 11, accessory lobes of aedeagus, dorsal view, not measured. Scale bar in mm.