Adamastoraltica, Biondi & Iannella & D’Alessandro, 2020

Biondi, Maurizio, Iannella, Mattia & D’Alessandro, Paola, 2020, Adamastoraltica humicola, new genus and new species: the first example of possible moss-inhabiting flea beetle genus from sub-Saharan Africa (Coleoptera Chrysomelidae, Galerucinae), Zootaxa 4763 (1), pp. 99-108 : 100-103

Adamastoraltica gen. nov.

Description. Body ovate and very convex, with maximum pronotal width at base and maximum width of elytra at middle ( Figs 1, 3 ); elytral base as wide as pronotal base ( Fig. 4 ). Dorsal surface glabrous, metallic, apparently smooth, but with very sparse and very shallow punctation ( Figs 1, 3–4 ). Head ( Figs 5–6 ) with supraorbital, suprantennal and suprafrontal sulci distinctly impressed and joined, forming a continuous groove; supraorbital pore poorly visible; area of frontal calli paler, but neither delimited nor raised; inter-antennal space slightly wider than length of the first antennomere; frons length (from upper orbital line to clypeus) distinctly longer than the inter-antennal space; frontal ridge slightly raised; eyes sub-elliptical, small. Mouth parts ( Fig. 7 ) with clearly medially-incised labrum; three-segmented and flat maxillary palpi; three-segmented and thickset labial palpi. Antennae about as long as half body length ( Fig. 1 ), with last antennomeres distinctly wider than middle ones. Pronotum ( Figs 1, 3–5 ) very convex, in dorsal view transverse, subtrapezoidal, with converging anteriorly sides; margins very finely bordered; anterior and posterior angles not prominent; anterolateral setiferous pore very small, placed on the vertex of the anterior angle ( Fig. 5 ). Scutellum absent ( Fig. 4 ). Metathoracic wings absent. Elytra ( Figs 1–3 ) moderately elongate, strongly convex, with clearly rounded sides and thin lateral margins, apically jointly acute; epipleurae ( Fig. 2 ) very wide, horizontally oriented, little visible in lateral view. Humeral calli absent. Procoxal cavities posteriorly open ( Fig. 2 ). Pro-, meso- and metasternum short ( Fig. 2 ); intercoxal process of prosternum about as wide as supracoxal part, laterally subparallel; medial process of both metasternum and first abdominal ventrite distinctly elongate and anteriorly acute. Hind femora slightly swollen ( Fig. 2 ); hind tibiae ( Fig. 8b ) longitudinally not channelled, without any spines or teeth on lateral margins; apical spur of hind tibiae simple; first metatarsomere as long as second and third together ( Fig. 8c ); third tarsomere of all legs very deeply incised; tarsal claws simple ( Fig. 8a ). Metafemoral extensor tendon ( Fig. 9 ) with dorsal lobe slightly and evenly curved; extended arm of the dorsal lobe elongate; tendon basal edge straight, forming an acute dorsal-basal angle with the dorsal lobe; tendon central furrow very wide; dorsal edge of the ventral lobe straight, angled downward; basal angle of the ventral lobe slightly acute, not pointed apically; recurved flange significantly sclerotized. Metafemoral extensor tendon displays many similarities with the Altica Morpho-Group ( Furth & Suzuki 1998) . Median lobe of aedeagus ( Fig. 10 ) simple, lacking ventral sulcus and other sculptures, evenly curved in lateral view, with a large dorsal ligula. Spermatheca of Alticinae-type ( Furth & Suzuki 1994) ( Fig. 11a ) with sub-cylindrical basal part; distal part distinctly shorter than basal part, lacking a distinct collum and appendix; ductus short, uncoiled, U-shaped, apically inserted. Tignum ( Fig. 11b ) elongate and narrow, in lateral view basally and apically clearly curved; vaginal palpi ( Fig. 11c ) thin, basally not connected, moderately sclerotized along their entire length, apically with three setae.

Type species. Adamastoraltica humicola sp. nov.

Etymology. The name of the new genus means “flea beetle of Adamastor”, a mythological figure of Titan transformed into a towering mountain in order to protect the Cape from passing sailors who dared to discover the African continent’s mysteries. Gender: feminine, because of the “ altica ” suffix.

Distribution. Republic of South Africa, Western Cape Province ( Table 1; Fig. 12 ).

Taxonomic notes. Adamastoraltica gen. nov., known from a single species collected in humus, appears very similar to most moss-inhabitant flea beetle genera distributed worldwide ( Fig. 12 ), possibly due to adaptation to similar environmental conditions of their habitat (see “Introduction” and “Discussion”). Possible adaptive convergences concern: very small size, very convex and subglobose body, antennae with enlarged apical antennomeres, strongly reduced hind wings, greatly simplified and shortened mesothorax and metathorax, and elytra lacking humeral calli. However, the new genus shares some characters with the Asian genus Cangshanaltica Konstantinov, Chamorro, Prathapan, Ge, and Yang , know from China, Hong Kong and Thailand ( Damaška & Aston 2019; Damaška & Konstantinov 2016; Konstantinov et al. 2013), such as: labrum apically deeply incised ( Fig. 7 ); antennae not clavate ( Fig. 1 ); anterior coxal cavities posteriorly open ( Fig. 2 ); base of pronotum without transverse impression ( Figs 1 , 4–5 ); first abdominal ventrite with longitudinal ridges between metacoxae ( Fig. 2 ); third tarsomere narrow and deeply incised ( Figs 1, 3 , 8a, c ). The new genus is, however, easily distinguishable from Cangshanaltica by: suprantennal and suprafrontal sulci distinctly impressed ( Fig. 6 ) (shallow, barely visible in Cangshanaltica ); pronotal anterolateral setiferous pore very small, placed on vertex of the anterior angle ( Fig. 5 ) (almost in the middle of the lateral margin in Cangshanaltica ); pronotum with posterolateral callosity absent ( Figs 1 , 4–5 ) (present and slightly protruding in Cangshanaltica ); scutellum absent ( Fig. 4 ) (present in Cangshanaltica ); metafemurs slightly swollen ( Fig. 2 ) (robust in Cangshanaltica ); hind tibiae longitudinally not channelled, without any spines or teeth on lateral margin ( Fig. 8b ) (clearly channelled with small spines on lateral margin in Cangshanaltica ); apical spur of the hind tibiae barely distinguishable among tibial setae, very shorter than tarsal claws ( Fig. 8b ) (longer in Cangshanaltica ); tarsal claws simple ( Figs 8a, c ) (subappendiculate in Cangshanaltica ). The lack of scutellum, a peculiar character of Adamastoraltica gen. nov., is shared with Stegnaspea Baly , a genus generally associated with Poaceae and also occurring in the Western Cape Province with six species ( D’Alessandro et al. 2012). The new genus, however, is clearly distinguishable from Stegnaspea by the following characters: body surface apparently smooth, with very sparse and very shallow punctation ( Figs 1, 3–4 ) (clearly punctate in Stegnaspea ); labrum medially incised ( Fig. 7 ) (rounded in Stegnaspea ); maxillary palpi flat ( Figs 6–7 ) (slender in Stegnaspea ); frontal calli absent ( Fig. 6 ) (present in Stegnaspea ); medial processes of metasternum and first abdominal ventrite comparatively narrow and elongate ( Fig. 2 ) (wider and shorter in Stegnaspea ); tarsal claws simple ( Figs 8a, c ) (subappendiculate in Stegnaspea ); metafemoral extensor tendon attributable to the Altica morpho-group sensu Furth & Suzuki (1998) ( Fig. 9 ) (attributed to the Chaetocnema morpho-group in Stegnaspea ); median lobe of aedeagus simple ( Fig. 10 ) (with complex sculptures in Stegnaspea ); spermatheca without distinct collum and with short, apically inserted ductus ( Fig. 11a ) (with distinct collum and longer, sub-apically inserted ductus in Stegnaspea ).

Figures

FIGURE 12. Geographical distribution of the moss-inhabiting flea beetle genera, excluding subtribe Monoplatina.

FIGURES 1–3. Adamastoraltica humicola sp. nov. habitus, ♂ holotype: 1, dorsal view; 2, ventral view; 3, lateral view. 1st av = first abdominal ventrite; ep = elytral epipleurae; ms = mesosternum; mt = metasternum; ps = prosternum.

FIGURES 4–11. Adamastoraltica humicola sp. nov. from Wynberg Cave Ravine: 4, pronotum and basal part of elytra in dorsal view; 5, head and pronotum in dorsolateral view; 6, head in dorsal view; 7, mouthparts; 8, male, front tibia and tarsus (a), hind tibia (b), hind tarsus (c); 9, metafemoral extensor tendon, from top to bottom in inner and outer view; 10, aedeagus from left to right in ventral, dorsal, and lateral view; 11, spermatheca (a), tignum (b), vaginal palpi (c). 1st = first tarsomere, 3rd = third tarsomere, aa = anterior angle, as = apical spur; bav = basal angle of the ventral lobe; be = tendon basal edge; cf = tendon central furrow; dba = dorsal-basal angle; dev = dorsal edge of ventral lobe; dl = dorsal lobe; ea = extended arm; lb = labrum; lp = labial palpus; mp = maxillary palpus; pa = posterior angle, rf = recurved flange; sg = supraorbital groove, tc = tarsal claws, vl = ventral lobe.