Dismegistus madagascariensis sp. nov.

Figs 1–3, 8–13, 14–19

? Dismegistus pauliani (nomen nudum): Leston (1956): 92 (Madagascar).

Type locality.

South-east Madagascar, Anosy mountain range, Andohahelo plateau [Andohahela National Park], SW of Trafonaomby Mt., 1770–1950 m a. s. l. (ca. 24°33'54"S, 46°43'14"E).

Type material.

Holotype: ♀ (Figs 1–3), ‘ Chaînes anosyennes / S. O. du Trafonaomby / plateau Andohahelo / 1770 ‧ 1950 m, V. - 1972 [p] // Museum Paris [p] / A. Peyrieras / I. 1974 [hw] // ♀ [p] // HOLOTYPUS / DISMEGISTUS / MADAGASCARIENSIS / sp. nov. / des. P. Kment & J. A. Lis 2025 [p, red label] ’ (MNHN). The holotype was remounted on a new piece of card, with a trace of past pinning on the scutellum; hemelytra slightly spread, abdominal ventrites depressed (Fig. 2); both distiflagella, left basiflagellum, both protarsi, right mesotarsus and left metatibia and metatarsus missing (Fig. 1).

Description

(female). Coloration (Figs 1, 2). Body, antennae, and legs black, pronotum and propleura bright orange-red; apex of scutellum with narrow reddish-brown margin; clavi black; coria (including hypocostal lamina) reddish-black, basally and along each R + M vein darker (against the surface of abdomen corium appearing black), lateral margins of coria dark red; membranes translucent, fumose brown; anterolateral angle of each mesepisternum red, metepimera reddish-black (Fig. 2).

Structure.

Head triangular in dorsal (i. e., frontal) view (Fig. 10), declivous (Figs 8, 9). Mandibular plates slightly surpassing apex of clypeus to form anterior notch (Figs 10, 11). Lateral margins of head elevated dorsally in form of ridges, remaining surface of mandibular plates and clypeus flat (Fig. 10), vertex between eyes and ocelli convex (Fig. 9). Bucculae crescent shaped, ca. as long as labiomere I (Fig. 9). Labium (Fig. 14) reaching middle of mesosternum (Fig. 15). Length of labiomeres III> IV> II> I, labiomere I reaching about head midlength (Fig. 14). Antenna with scape (I) shortest, stoutest, basipedicellite (IIa) and distipedicellite (IIb) about same length, cylindrical, only slightly wider apically than at base (Figs 1, 2), basiflagellum (III) spindle-shaped, slightly flattened, longer than preceding antennomeres, distiflagellum (IV) missing in examined specimen.

Pronotum (Figs 1, 12) with anterior margin shallowly concave, anterolateral and humeral angles broadly rounded; lateral margins narrowly explanate, convex in dorsal view, slightly curved dorsally in lateral view; posterior margin slightly concave in middle. Pronotal disc with very shallow, almost indistinct sublateral depression anterolaterally (Fig. 12). Scutellum triangular with convex surface, insinuate at frenal apices, apex of scutellum broadly rounded posteriorly (Figs 1, 13).

Coria somewhat explanate laterally each with well developed hypocostal lamina (Fig. 2); costal margins of coria convex in dorsal view (Figs 1, 2, 13), each exocorium with depressed medial furrow (Fig. 13: mf) anteriorly between Sc and R + M veins, posterior margin of each corium rounded (Fig. 1); veins of membranes translucent, indistinct.

Thoracic sterna neither grooved or keeled (Fig. 15). External scent efferent system of metathoracic scent glands (Fig. 16) reduced, ostioles V-shaped (Fig. 16: o), each situated between meso- and metacoxal cavities, vestibulum and vestibular scars very short, peritremes not emarginated, peritremal sufaces merging with surrounding metapleura, only median furrow well-developed (Fig. 16: mf); evaporatoria (Fig. 16: ev) rudimentary, mycoid surface limited to small area posteriad of ostioles, elongate patch along suture between meso- and metapleura. Femora simple, oval in cross-section; tibiae with dorsal surface shallowly grooved (Fig. 8). Tarsomere I stoutest, longest, longer than II + III combined, tarsomere III longer than II.

Each abdominal ventrite bearing two trichobothria postero- / posterolaterad of each spiracle (Fig. 18: sp, tr), bothrium of type A (Fig. 19). Female terminalia (Fig. 17) with valvifers VIII semicircular with posterior margin slightly rounded (Fig. 17: vf 8), laterotergites IX small, triangular, with lateral margins rounded (Fig. 17: lt 9); laterotergites VIII medially fused (Fig. 17: lt 8).

Integument and vestiture.

Pronotum and head shining, scutellum and hemelytra submatte (Fig. 1). Head (Figs 10, 11) impunctate, clypeus basally and apically with shallow transverse wrinkles, mandibular plates laterally with transverse wrinkles fading centrally (Fig. 10). Pronotum with sparse, shallow, concolorous punctures, more pronounced in center of disc (Fig. 12). Scutellar disc with concolorous punctures, sparse, shallow basally, more pronounced, connecting with transverse wrinkles in central and posterior parts of disc (Fig. 13). Clavi and coria with dense concolorous punctures, deeper, denser than on pronotum. Ventral surface of body nearly smooth (Figs 14–19), metepimera with large shallow punctures.

Body bare except distipedicellite (IIb) and basiflagellum (III) with fine, short, semierect pilosity. Each tibia with four rows of stout black semierect spines, one row dorsally on each side of of flattened dorsal surface (Fig. 8), two rows on ventral surface, their spines forming acute angle ventrally; besides the stout spines each tibia bearing additional finer, shorter setae. Tarsi with short, semierect to erect setae, especially dense on ventral surfaces.

Measurements (mm). Body length 8.33; head: length 1.35, width (including compound eyes) 2.10, interocular width 1.37; lengths of labiomeres: I – 0.35, II – 0.60, III – 0.82, IV – 0.76; lengths of antennomeres: I – 0.52, IIa – 1.02, IIb – 1.00, III – 1.32, IV – missing; pronotum: length 2.42, width 5.05; scutellum: length 3.23, width 2.94.

Male. Unknown.

Differential diagnosis.

The new species is similar in body length to D. cf. fimbriatus, D. cf. funebris Distant, 1900, and D. royeri Jeannel, 1913. The females of these species, measuring approximately 5.0 mm to nearly 9.0 mm in length, are smaller than those of other species within this genus, such as D. cf. binotatus, D. cf. costalis Reiche & Fairmaire, 1849, and D. cf. rufomarginatus Hesse, 1925, where the female body length typically exceeds 10.0 mm and can occasionally reach as much as 16.0 mm. However, D. madagascariensis can be easily distinguished from D. cf. fimbriatus, D. cf. funebris, and D. royeri by the coloration of the pronotum and hemelytra. The pronotum of D. madagascariensis is uniformly red on the dorsal side, unlike the other three species, where only the lateral portions and posterior parts of the pronotum show red. The same applies to the outer sections of the exocoria, which in D. cf. fimbriatus, D. cf. funebris, and D. royeri are predominantly red along their length and distinctly differ in color from the darker mesocoria. In D. madagascariensis, the base of each exocorium is noticeably darker, resembling the color of the mesocorium. Furthermore, unlike all other species in the genus, the hemelytra of D. madagascariensis are broadly expanded laterally, reaching distinctly laterad of the humeral angles.

Etymology.

The species epithet is the Latinized adjective madagascariensis (- is, - e), referring to the area of the species distribution.

Habitat and biology.

Unknown. The type locality, Andohahela National Park, is situated at the southern end of the Malagasy Highlands. The park is divided into three zones. The first zone, Malio, ranges from 100 meters to the summit of Pic d’Andohahela at 1,956 meters, and has dense lowland and montane rainforest. The second zone, Ihazofotsy-Mangatsiaka, contains dry spiny forest at altitudes ranging from 100 to 1,005 meters at the summit of Pic de Vohidagoro. The third zone, Tsimelahy, is mainly at an altitude of 125 meters and contains the unique Ranopiso transitional forest. The mountains form a natural barrier to the moist trade winds that blow from the east, causing on the eastern side a rainfall of 1,500–2,000 millimeters per year that supports one of the few rain forests south of the Tropic of Capricorn. At the park’s western edge, the rainfall is just 600–700 millimeters per year, and the resulting vegetation is a dry, spiny forest characteristic of southern Madagascar (Paulian et al. 1973; Anonymus 2025). As the holotype label indicates, the specimen was collected at the leeward south-west slopes of Trafonaomby Mt. (1770–1950 m a. s. l.), i. e., just under the mountain top. This suggests its finding in the forest zone, though the exact type of forest would be just a speculation. Collecting fresh specimens is necessary to elucidate the bionomy and habitat requirements of the new species. The available habitat information concerning the species in continental Africa concerns relatively drier habitats (e. g., Lis and Domagała 2024).

Distribution.

Known only from the type locality, Trafonaomby Mt. in south-east Madagascar.

Remark.

When examining species of Dismegistus, Leston (1956) noted that his study was based on material from various regions of South Africa (D. cf. fimbriatus, D. cf. binotatus) and Madagascar (D. pauliani). Although a Latin name was assigned to the species from Madagascar, Leston classified it as a nomen nudum. Concurrently, he suggested that the species would be described once sufficient material became available to undertake a comprehensive revision of the entire genus Dismegistus. Unfortunately, this species from Madagascar was neither described by Leston nor mentioned in his subsequent publications. Consequently, it is currently difficult to determine whether the specimens used as the basis for D. pauliani represent the same species described in this paper. Nevertheless, given that these are the only specimens of this genus recorded from Madagascar, the name D. pauliani has been tentatively included as a nomen nudum under D. madagascariensis.