A revision of Discodon tricolor (Guérin-Méneville) and its mimics from the Atlantic forests of Brazil (Coleoptera: Cantharidae)

. Discodon tricolor (Guérin-Méneville, 1832) was thought to be a common species widely distributed in the Atlantic Forests of Brazil, yet showing morphological and chromatic variations. After examination of a large number of specimens from different regions of the Atlantic Forest biome, we found that Discodon tricolor actually represents a complex of many similar and sometimes sympatric species. Thirteen species in this complex are recognised as valid: Discodon tricolor , D. neoteutonum sp. nov., D. vanini sp. nov., D. obscurior Pic, 1906 stat. nov., D. lineaticorne sp. nov., D. aurimaculatum sp. nov., D. marginicolle sp. nov., D. tenuecostatum sp. nov., D. nigrocephalum Pic, 1949, D. tamoio sp. nov., D. viridimontanum sp. nov., D. crassipes Wittmer, 1952, and D. testaceipes Pic, 1930 stat. nov. The species Discodon albonotatum Pic, 1906 is confirmed as a synonym of D. tricolor , while the subspecies D. albonotatum obscurior and D. albonotatum testaceipes are elevated to specific status. The subgenus Acanthodiscodon Wittmer, 1952 is synonymised with Discodon Gorham, 1881. All the species are described and illustrated in detail and an identification key is provided. Despite being chromatically similar, the species show major morphological differences in their aedeagus and antennal structures, suggesting that they do not form a monophyletic clade. A potential mimicry ring involving these species of Discodon as well as other members of Cantharidae, Lampyridae, Cerambycidae and Belidae is discussed. Comments are made on the conservation of these species and their habitats within the Atlantic Forest biome. central projection curved dorsally; lateral margins of ventral wall rounded and divergent, with long and thick setae on distal margin and inside; central projection parallel and with a pair of longitudinal ridges proximally, and widened, flattened, with small triangular spine distally, apex with longitudinal slit; parameres short and stout, apex truncate; median lobe short, membranous, with a pair of strong triangular dorsal sclerites and brush-like projections laterally and ventrally.


Diagnosis
Discodon tricolor differs from the other species for having most of the antennomeres yellow. Discodon tricolor is similar to D. vanini sp. nov. and D. neoteutonum sp. nov., differing from these species by the ventral wall of the tegmen  longer, about as long as wide, and the median lobe with a narrow central sclerite; the last ventrite of the females (Fig. 15A) with a distal margin almost straight, with a slight median projection.

Re-description
Body length: 10.4-14.0 mm. Coloration (Fig. 2): head pitch black, lustrous, except in front of antennae sockets and anterior margin of clypeus, dark brown; mandibles dark brown, darker at base and the tip; maxillary and labial palpi black, except apex of last palpomeres, dark brown; antennomeres I and sometimes II black, the latter testaceous to light brown. Pronotum (Figs 7A, 8A) lustrous, translucent, with broad irregular black band from anterior to posterior margin, wider posteriorly and narrower near anterior margin; background bright yellow to light orange with barely defined orange and brown lateral patches. Scutellum and elytra pitch black, slightly lustrous; at mid-length of each elytron, large whitish to pale yellow round spot nearly reaching lateral borders but not meeting at suture. Thorax, legs and abdomen pitch black, tarsal claws brown.

Female
Similar to male; antennae (Fig. 6L) shorter, antennomeres less broad; pronotum (Fig. 8A) trapezoidal, much broader, 1.7 times as wide as long, lateral margins sinuate, without notches; tarsal claws without basal lobe or apical slit; ventrite VI not notched, distal margin slightly arched, concave; ventrite VII ( Fig. 15A) broad, lateral margins arched, distal margin sinuous, with a short and broad medial lobe. Delkeskamp (1977) and Wittmer (1977) both indicated Guérin-Méneville's 1844 work as the original reference for Silis tricolor, since it contains the first published description of that species. Delkeskamp (1977) also cites "Blanch. in Griffith, Anim. Kingdom 1, 1832, l. 36, fig. 10", a plate published 12 years prior to Guérin-Méneville's description. According to ICZN Art. 8.7, an illustration of a species published before 1930 that is accompanied by a new name does however already count as a valid description "by indication" and makes this name available, even without being accompanied by a description in words or an explicit statement that the name is new. We therefore regard the illustration in Griffith's "Animal Kingdom" as the first available evidence of this species. As the species name Silis tricolor is explicitly attributed to "Guérin" on Griffith's plate, F.E. Guérin-Méneville remains the author of the species (not Blanchard), but the year of description must be corrected to 1832.

Distribution
Brazil (Minas Gerais, Rio de Janeiro and São Paulo states) (Fig. 16 (Fig. 3A), the aedeagus  with distal margin of tegmen shorter, apical lobes less pronounced; the median lobe with a very broad central sclerite; females with ventrite VII (Fig. 15B) broader, with a more pronounced median projection.

Etymology
The epithet neoteutonum refers to the type locality of the species, Nova Teutônia, a district in the Seara municipality in Santa Catarina state, Brazil.

Description
Body length: 10.4-13.0 mm. Coloration (Fig. 3A): head pitch black, lustrous, except in front of antennae; sockets dark brown; mandibles dark brown, darker at the base and the tip; maxillary and labial palpi black; antennae black, except last three antennomeres, sometimes lighter, and ventral face of antennomere I dark brown. Pronotum (Figs 7B, 8B) lustrous, translucent, with a broad irregular black band from anterior to posterior margin, wider anteriorly and narrower near the middle; background bright yellow to light orange with barely defined orange to brownish lateral patches. Scutellum and elytra pitch black, slightly lustrous; at mid-length of each elytron, a large sulphur to pale yellow hemispheric to triangular spot nearly reaching the lateral borders but not meeting at the suture. Thorax, legs and abdomen pitch black, tarsal claws dark brown.
Male (Fig. 3A) Head short, nearly as long as wide, excluding eyes; integument smooth, densely covered with short and fine yellow setae; frons short; vertex flat; occipital region convex, broadly rounded behind the eyes. Clypeus flat, anterior margin emarginate, with pair of lobes slightly projected anteriorly. Eyes small, rounded, prominent. Mandibles falciform, acute, without accessory teeth. Last maxillary and labial palpomeres securiform. Antennae (Fig. 6B) slightly flattened dorsoventrally; antennomeres wider distally; antennomeres IX-XI slightly narrower than the preceding. Pronotum (Fig. 7B) about 1.5 times as wide as long; anterior margin broadly arched, anterior angles indistinct; lateral margins with a shallow notch at posterior third, pronotum wider behind notch; integument smooth, densely covered with very fine yellow setae. Elytra long, each elytron about 4 times as long as wide, almost parallel, slightly wider in the middle; integument coriaceous, densely covered with short and fine decumbent setae, and much longer thick erect setae. Legs slender, densely pubescent, covered with long and thick setae; tarsi flattened dorsoventrally, fourth tarsomere with a transversal slit at base; anterior prothoracic tarsal claws (Fig. 9B) with tip pointing externally, broadly lobed basally, lobe with sinuous margin; posterior claws on meso-and metathoracic tarsal claws apparently split at the apex, with fine protruding tooth shorter than claws. Abdomen weakly sclerotised, coriaceous, densely covered with long setae; ventrite VI deeply notched at posterior margin, V-shaped, lateral apices arched; ventrite VII ( Fig. 10B) elongate, oblong, strongly concave, internal margins arcuate, directed ventrally, distal margins projecting posteriorly, apices rounded. Aedeagus : ventral wall of tegmen short and broad, lateral margins slightly convergent, distal margin forming a pair of broadly rounded lobes; between lobes, small acute tip directed ventrally; fringe of long setae along lateral margins of tegmen dorsally; parameres broadly separated, robust, long and broad, parallel, curved ventrally, apex rounded; median lobe short, membranous, partially retracted behind parameres; very broad central sclerite curved ventrally with broadly rounded apex.

Distribution
Brazil (Santa Catarina and Rio Grande do Sul states) (Fig. 16 Diagnosis Similar to D. tricolor and D. neoteutonum sp. nov. It differs from these species by the last two or three antennomeres being orange to light brown (Fig. 3B); the ventral wall of the tegmen (Fig. 11G-I) less distinctly narrowed laterally, the central sclerite of the median lobe broader than in D. tricolor and narrower than in D. neoteutonum; the last ventrite (VII) of females with distal margin sinuate (Fig. 15C).

Etymology
The specific epithet is patronymic, named in honour of the late Professor Sergio A. Vanin (1948Vanin ( -2020 in appreciation of his enormous and enduring contribution in the study and teaching of zoology, especially Coleoptera systematics.

Description
Body length: 9.7-13.0 mm. Head pitch black, lustrous, except in lateral corners of clypeus, dark brown; mandibles dark brown, darker at base and tip; maxillary and labial palpi black; antennae black, last two or three antennomeres orange to light brown. Pronotum lustrous, translucent, with broad irregular black band from anterior to posterior margin, wider posteriorly and narrower near middle; background bright yellow to light orange with well-defined diagonal orange and brown patches laterally. Scutellum and elytra pitch black, slightly lustrous; at mid-length of each elytron, large whitish to pale yellow round spot nearly reaching lateral borders but not meeting at suture. Thorax, legs and abdomen pitch black, tarsal claws brown.
Male (Fig. 3B) Head short, nearly as long as wide, excluding eyes; integument smooth, densely covered with short and fine yellow setae; frons short; vertex flat, occipital region convex, broadly rounded behind eyes. Clypeus flat, anterior margin emarginate, slightly projected anteriorly with a median incision. Eyes small, rounded, prominent. Mandibles falciform, acute, without accessory teeth. Last maxillary and labial palpomeres securiform. Antennae (Fig. 6C) slightly flattened dorsoventrally; antennomeres III-VIII wider distally; antennomeres IX-XI narrower and less expanded distally than preceding ones. Pronotum (Fig. 7C) about 1.5 times as wide as long; anterior margin almost straight, anterior angles arched; lateral margins with shallow notch at posterior third, pronotum wider behind notch; integument smooth, densely covered with very fine yellow setae. Elytra long, each elytron 4.2 times as long as wide, wider at middle; integument coriaceous, densely covered with short and fine decumbent setae, and much longer thick erect setae. Legs slender, densely pubescent, covered with long and thick setae; tarsi flattened dorsoventrally, fourth tarsomere with a transversal slit at base; anterior prothoracic tarsal claws (Fig. 9C) broadly lobed basally, lobe with sinuous margin; posterior claws on meso-and metathoracic tarsal claws apparently split at the apex, with fine protruding tooth shorter than claws. Abdomen weakly sclerotised, coriaceous, densely covered with long setae; ventrite VI deeply notched at posterior margin, V-shaped, lateral apices arched; ventrite VII ( Fig. 10C) elongate, oblong, strongly concave, internal margins arcuate, directed ventrally, distal margins projecting posteriorly, apices rounded. Aedeagus : ventral wall of tegmen short and broad, lateral margins slightly convergent, distal margin forming a pair of broadly rounded lobes; between lobes, small acute tip directed ventrally; fringe of long setae along lateral margins of tegmen dorsally; parameres broadly separated, robust, long and broad, parallel, curved ventrally, apex rounded; median lobe short, membranous, partially retracted behind parameres; broad central sclerite curved ventrally, with apex narrowly rounded.

Diagnosis
Similar to D. nigrocephalum by general coloration (Fig. 5A-B). It differs especially by the elytra being smoother (

Re-description
Body length: 11.0-13.0 mm. Coloration : head pitch black, lustrous, except in lateral corners of clypeus, dark brown; mandibles dark brown, darker at base and tip; maxillary and labial palpi dark brown, light brown in last palpomeres; antennomere I black, the latter light brown, sometimes orangish. Pronotum (Figs 7D, 8D) lustrous, partly translucent, with broad irregular black band from anterior to posterior margin, black band usually with lateral projections in posterior third; background pale yellow with diffuse orange regions. Scutellum and elytra entirely pitch black, slightly lustrous. Thorax, legs and abdomen black, tarsal claws brown. (Fig. 5A-B) Head short, slightly wider than long, excluding eyes; integument smooth, densely covered with short and fine yellow setae; frons short, vertex flat, occipital region convex, broadly rounded behind eyes. Clypeus flat, anterior margin emarginate, slightly projected anteriorly with median incision. Eyes large, rounded, slightly prominent. Mandibles falciform, acute, without accessory teeth. Last maxillary and labial palpomeres securiform. Antennae (Fig. 6D) long, slightly flattened dorsoventrally; antennomeres III-X narrowing proximally, sub-serrate; antennomeres without longitudinal lines. Pronotum (Fig. 7D) wide, 1.5 times as wide as long; anterior margin, anterior angles and lateral margins broadly arched; lateral margins with shallow notch at posterior third; integument smooth, densely covered with very fine yellow setae. Elytra long, each elytron 4.2 times as long as wide, wider medially; integument coriaceous, densely covered with short and fine decumbent setae, and much longer thick erect setae. Legs slender, densely pubescent, covered with long and thick setae; tarsi flattened dorsoventrally, fourth tarsomere with transversal slit at base; anterior prothoracic tarsal claws (Fig. 9D) broadly lobed basally, lobe with sinuous to truncate margin; posterior claws on meso-and metathoracic tarsal claws apparently split at apex, with fine protruding tooth slightly shorter than claws. Abdomen weakly sclerotised, coriaceous, densely covered with long setae; ventrite VI notched at posterior margin; ventrite VII ( Fig. 10D) with concave lobes, inner margins divergent, directed ventrally, with sharp borders; outer margins straight, apical margins truncate, meeting medially. Aedeagus : ventral wall of tegmen short, lateral  Pic, 1930 (syntype, ♂, NHMB), dorsal habitus and labels. F-G. Discodon albonotatum testaceipes Pic, 1930 (syntype, ♀, NHMB), dorsal habitus and labels. Photos B-G by Matthias Borer (NHMB). Scale bars = 5.0 mm. margins convergent from apical half; apex forming a pair of rounded lobes and salient border projecting ventrally; fringe of long setae along lateral margins of tegmen dorsally; parameres very long, robust, falciform, projecting dorsally, apex rounded with small acute tip; median lobe membranous, with very long and broad flattened central sclerite dorsally.

Etymology
The epithet lineaticorne refers to the longitudinal antennal lines on antennomeres IX-XI of the males.

Description
Body length: 13.0-14.3 mm. Coloration (Fig. 3C): head pitch black, lustrous, except in lateral corners of clypeus, light brown; mandibles light brown, darker at base and tip; maxillary and labial palpi dark brown to black, light brown at apex of last palpomeres; antennae entirely black. Pronotum (Figs 7E, 8E) lustrous, partly translucent, with broad irregular black band from anterior to posterior margin, wider anteriorly and near posterior margin, and narrower near anterior half; from median band, a pair of diagonal black bands; background pale yellow to light orange with barely defined orange patches. Scutellum and elytra pitch black, slightly lustrous; at mid-length of each elytron, large whitish to pale yellow round spot nearly reaching lateral borders but not meeting at suture. Thorax, legs and abdomen dark brown to black, tarsal claws brown.
Male (Fig. 3C) Head short, nearly as long as wide, excluding eyes; integument smooth, densely covered with short and fine yellow setae; frons short, vertex flat, occipital region convex, broadly rounded behind eyes. Clypeus flat, anterior margin emarginate, slightly projected anteriorly with median incision. Eyes large, rounded, prominent. Mandibles falciform, acute, without accessory teeth. Last maxillary and labial palpomeres securiform. Antennae (Fig. 6E) long, slightly flattened dorsoventrally; antennomeres III- IX wider distally, sub-serrate; antennomeres IX-XI with short longitudinal lines dorsally. Pronotum (Fig. 7E) wide, about 1.5 times as wide as long; usually, anterior margin slightly arched, almost straight in middle, anterior angles arched; lateral margins slightly sinuate, with shallow notch at posterior third; anterior, posterior and lateral margins elevated; integument smooth, densely covered with very fine yellow setae. Elytra long, each elytron 5 times as long as wide, almost parallel; integument coriaceous, densely covered with short and fine decumbent setae, and much longer thick erect setae. Legs slender, densely pubescent, covered with long and thick setae; tarsi flattened dorsoventrally, fourth tarsomere with transversal slit at base; anterior prothoracic tarsal claws (Fig. 9E) broadly lobed basally, lobe with rounded margin; posterior claws on meso-and metathoracic tarsal claws apparently split at apex, with fine protruding tooth slightly shorter than claws. Abdomen weakly sclerotised, coriaceous, densely covered with long setae; ventrite VI deeply notched at posterior margin, V-shaped, lateral apices arched; ventrite VII ( Fig. 10E) with parallel-sided lobes, distal margins truncate; ventrite lobes concave, internal margins directed ventrally. Aedeagus : ventral wall of tegmen long and broad, apical margin convergent, forming a pair of lateral projections with truncate apices and very long central projection, strongly curved ventrally and with hook-like apex, usually visible between lobes of ventrite VII; fringe of long setae along lateral margins of tegmen dorsally; parameres robust, long and broad, parallel, apex acute; median lobe short, membranous, partially retracted behind parameres.

Female
Similar to male; antennae (Fig. 6) shorter, without longitudinal lines; pronotum wider, 1.6 times as wide as long, lateral margins without notches; tarsal claws without basal lobe or apical slit; ventrite VI not notched, distal margin slightly arched, concave; ventrite VII broad, lateral and distal margins broadly arched, distal margin with two long apical lobes projecting posteriorly at middle and U-shaped medial notch.

Diagnosis
Differs from all the other species by the elytra with the weakly defined longitudinal roughness and dark yellow spots (Fig. 3D), the shape of the aedeagus (Fig. 12D-F) and the last ventrite (VII) of the females (Fig. 15F).

Etymology
The specific epithet aurimaculatum refers to the dark yellowish to golden rounded elytral spots.

Description
Body length: 11.7-13.0 mm. Coloration (Fig. 3D): head pitch black, lustrous, except in lateral corners of clypeus, light brown; mandibles light brown, darker at tip; maxillary and labial palpi black, light brown at apex of last palpomeres; antennae entirely black. Pronotum (Figs 7F, 8F) lustrous, partly translucent, with broad irregular black band from anterior to posterior margin, wider anteriorly and near posterior margin, and narrower near anterior half; no lateral dark bands or patches; background pale yellow to light orange with barely defined orange regions. Scutellum and elytra pitch black; at mid-length of each elytron, pale-yellow round spot meeting lateral borders but not meeting at suture. Thorax, legs and abdomen dark brown to black, tarsal claws brown.
Male (Fig. 3D) Head short, nearly as long as wide, excluding eyes; integument smooth, densely covered with short and fine yellow setae; frons short, vertex flat, occipital region convex, broadly rounded behind eyes. Clypeus flat, anterior margin emarginate, slightly projected anteriorly with shallow median incision. Eyes small, rounded, prominent. Mandibles falciform, acute, without accessory teeth. Last maxillary and labial palpomeres securiform. Antennae (Fig. 6F) long, slightly flattened dorsoventrally; antennomeres slightly narrowing anteriorly, sub-serrate; antennomeres without longitudinal lines dorsally. Pronotum (Fig. 7F) wide, about 1.4 times as wide as long; anterior margin slightly arched, anterior angles arched; lateral margins slightly sinuate, with deep notch at posterior third; integument smooth, densely covered with very fine yellow setae. Elytra long, each elytron 4.8 times as long as wide, almost parallel; weakly defined longitudinal roughness, like costae, more visible anteriorly; integument coriaceous, densely covered with short and fine decumbent setae, and much longer thick erect setae. Legs slender, densely pubescent, covered with long and thick setae; tarsi flattened dorsoventrally, fourth tarsomere with transversal slit at base; anterior prothoracic tarsal claws (Fig. 9F) broadly lobed basally, lobe with rounded margin; posterior claws on meso-and metathoracic tarsal claws apparently split at apex, with fine protruding tooth slightly shorter than claws. Abdomen weakly sclerotised, coriaceous, densely covered with long setae; ventrite VI slightly notched at posterior margin; ventrite VII ( Fig. 10F) with broad lobes, internal margins arched externally, apical margin broadly rounded. Aedeagus (Fig. 12D-F): ventral wall of tegmen elongate, apical margins convergent, forming a pair of parallel lateral projections with rounded apices and a short central projection, strongly curved ventrally and with acute hook-like apex; fringe of long setae along lateral margins of tegmen dorsally; parameres very short, hidden between tegmen and median lobe; median lobe long, membranous, with a pair of strong sclerites, each with double acute apices; sides of median lobe with tuft of thick spine-like setae.

Female
Similar to male; antennae (Fig. 6Q) shorter; pronotum (Fig. 8F) wider, 1.6 times as wide as long, lateral margins without notches; tarsal claws without basal lobe or apical slit; ventrite VI not notched, distal margin slightly arched, concave; ventrite VII ( Fig. 15F) broad, lateral and distal margins broadly arched, distal margin with two short acute apical lobes projecting posteriorly at middle and V-shaped medial notch.

Distribution
Brazil (Rio de Janeiro and São Paulo states) (Fig. 16). Diagnosis Similar to D. neoteutonum sp. nov. by the shape and coloration of the elytral spots. It differs from this species by the antennae being entirely black (Fig. 3E), with the antennal lines in males (Fig. 3G), the pronotum almost entirely black (Figs 7G, 8G), and the aedeagus with distal margin of the tegmen with three projecting lobes ; females with ventrite VII broad, with a sinuous distal margin and a less pronounced median projection (Fig. 15G). The aedeagus of D. marginicolle sp. nov. is similar to that of D. aurimaculatum sp. nov., differing in the shape of the distal projections of the ventral wall of the tegmen; besides, the antennae of D. aurimaculatum do not have antennal lines and the elytral spots are rounder.

Etymology
The specific epithet refers to the barely defined dark-orangish spot in the margin of the pronotum.

Description
Body length: 11.0-13.0 mm. Coloration (Fig. 3E): head pitch black, lustrous, except in corners of clypeus, dark brown; mandibles dark brown, darker at tip; maxillary and labial palpi black and antennae entirely black. Pronotum (Figs 7G, 8G) lustrous, mostly black, except for orangish to dark brown irregular patches near anterior and posterior angles. Scutellum and elytra pitch black; at mid-length of each elytron, large sulphur to greyish hemispheric to triangular spot nearly reaching lateral borders but not meeting at suture. Thorax, legs and abdomen pitch black, tarsal claws dark brown.
Male (Fig. 3E) Head short, nearly as long as wide, excluding eyes; integument smooth, densely covered with short and fine yellow setae; frons short; vertex flat; occipital region convex, broadly rounded behind eyes. Clypeus flat, anterior margin emarginate, with a pair of lobes slightly projected anteriorly. Eyes small, rounded, prominent. Mandibles falciform, acute, without accessory teeth. Last maxillary and labial palpomeres securiform. Antennae (Fig. 6G) sub-serrate, slightly flattened dorsoventrally; antennomeres III-VI wider distally, the latter nearly parallel, antennomere XI narrowing apically; antennomeres IX-XI with short longitudinal lines dorsally. Pronotum (Fig. 7G) about 1.1 times as wide as long; anterior margin slightly arched, anterior angles rounded; lateral margins with shallow notch at posterior third, pronotum wider near notch; integument smooth, densely covered with very fine clear setae. Elytra long, each elytron about 5.5 times as long as wide, almost parallel; integument coriaceous, densely covered with short and fine decumbent setae, and much longer thick erect setae. Legs slender, densely pubescent, covered with long and thick setae; tarsi flattened dorsoventrally, fourth tarsomere with transversal slit at base; anterior prothoracic tarsal claws (Fig. 9G) with pointing tip, broadly lobed basally, lobe with rounded margin; posterior claws on meso-and metathoracic tarsal claws apparently split at apex, with fine protruding tooth shorter than claws. Abdomen weakly sclerotised, coriaceous, densely covered with long setae; ventrite VI broadly concave at posterior margin; ventrite VII ( Fig. 10G) elongate, halves triangular, internal margins straight, lateral margins arched, apices rounded. Aedeagus (Fig. 12G-I): ventral wall of tegmen elongate, apical margins convergent, forming a pair of parallel lateral projections with acute apices and central projection, strongly curved ventrally and with acute hook-like apex; fringe of long setae along lateral margins of tegmen dorsally; parameres very short, hidden between tegmen and median lobe; median lobe long, conical, membranous, with a pair of strong sclerites, each with double acute apices; sides of median lobe with a tuft of thick spine-like setae.

Etymology
The name tenuecostatum refers to the weakly defined longitudinal elytral costulae in both males and females.

Description
Body length: 11.7-16.2 mm. Coloration (Fig. 5D): head pitch black, lustrous, except in lateral corners and anterior margin of clypeus, dark brown; mandibles dark brown, darker at base and tip; maxillary and labial palpi dark brown, light brown in last palpomeres; antennae black at base, clearing apicad, antennomeres I-II black, III-V dark brown, VI-XI light brown, sometimes III-V light brown and the latter orangish. Pronotum (Figs 7H, 8H) lustrous, partly translucent, with broad irregular black band from anterior to posterior margin, wider anteriorly and near posterior margin, and narrower near anterior half; background pale yellow with diffuse orange regions. Scutellum and elytra entirely pitch black, slightly lustrous. Thorax, legs and abdomen black, tarsal claws brown.

Male
Head short, as long as wide, excluding eyes; integument smooth, densely covered with short and fine clear setae; frons short, vertex flat, occipital region convex, broadly rounded behind eyes. Clypeus flat, anterior margin emarginate, slightly projected anteriorly with rounded median incision. Eyes small, rounded, prominent. Mandibles falciform, acute, without accessory teeth. Last maxillary and labial palpomeres securiform. Antennae (Fig. 6H) long, reaching elytral apical third, slightly flattened dorsoventrally; antennomeres narrowing proximally, sub-serrate, without longitudinal lines. Pronotum (Fig. 7H) wide, about 1.5 times as wide as long; anterior margin slightly arched, anterior angles arched; lateral margins sinuate, almost parallel anteriorly, and widened before lateral deep notch at posterior third; integument smooth, densely covered with very fine yellow setae. Elytra very long, each elytron 5.6 times as long as wide, almost parallel; integument coriaceous, densely covered with short and fine decumbent setae, and much longer thick erect setae. Legs slender, densely pubescent, covered with long and thick setae; tarsi flattened dorsoventrally, fourth tarsomere with transversal slit at base; anterior prothoracic tarsal claws (Fig. 9H) broadly lobed basally, lobe with very broad rounded margin; posterior claws on meso-and metathoracic tarsal claws apparently split at apex, with fine protruding tooth slightly shorter than claws. Abdomen weakly sclerotised, coriaceous, densely covered with long setae; ventrite VI with posterior margin concave; ventrite VII ( Fig. 10H) with triangular concave lobes, inner margins nearly parallel, directed ventrally, outer margins convergent posteriorly, apical margins rounded, with tip directed internally. Aedeagus (Fig. 12J-M) very robust, ventral wall of tegmen elongate, lateral margins constricted apically; apex forming a pair lobes with rounded projections, with strongly sinuous aspect; broad central projection, strongly flattened laterally with flat plaque-like projection ventrally, usually visible between ventrite lobes; fringe of long setae along lateral margins of tegmen dorsally; parameres very short, hidden between tegmen and median lobe; median lobe membranous, with strong falciform sclerites directed dorsally and central tufts of thick pubescence.

Female
Similar to male; antennae (Fig. 6S) shorter; pronotum (Fig. 8H) wider, 1.7 times as wide as long, subrectangular, anterior margin nearly straight, lateral margins without notch; tarsal claws without basal lobe or apical slit; ventrite VI not notched, distal margin slightly arched, concave; ventrite VII ( Fig. 15H) long and broad, lateral and distal margins broadly arched, apex with two long and broad apical lobes projecting posteriorly at middle and U-shaped medial notch.

Diagnosis
Similar to D. obscurior and D. tenuecostatum sp. nov. by the general coloration. It differs from these species by the wider head (Fig. 5F), apparently nearly as wide as the pronotum, the antennae black, and the elytra coriaceous, rough, without costulae (Fig. 5E).

Remarks
We were not able to examine the type specimen of D. nigrocephalum nor found similar specimens that could be attributed to this species. However, the photographs of the lectotype, deposited at the MNHN, Paris, enable the distinction between D. nigrocephalum on the one hand and D. obscurior and D. tenuecostatum sp. nov. on the other hand.

Diagnosis
Antennae entirely black (Fig. 3F), last ventrite (VII) of males with a strongly prominent acute tip directed ventrally (Fig. 10I); the last ventrite of the females (VII) with a distal margin with two apical rounded lobes projecting posteriorly at middle (Fig. 15I).

Etymology
The specific epithet refers to the Tamoio indigenous people, that inhabited the same region as D. tamoio sp. nov., currently comprising part of the coast of São Paulo and Rio de Janeiro states, Brazil.

Description
Body length: 10.4-13.6 mm. Coloration (Fig. 3F): head pitch black, lustrous, except in lateral corners of clypeus, dark brown; mandibles dark brown, darker at base and tip; maxillary and labial palpi black; antennae entirely black. Pronotum (Figs 7I, 8I) lustrous, translucent, with broad irregular black band from anterior to posterior margin, wider anteriorly and near posterior margin, and narrower near anterior half; background pale yellow to light orange with barely defined orange and brown lateral patches. Scutellum and elytra pitch black, slightly lustrous; at mid-length of each elytron, large whitish to pale yellow round spot nearly reaching lateral borders but not meeting at suture. Thorax, legs and abdomen pitch black, tarsal claws brown. (Fig. 3F) Head short, nearly as long as wide, excluding eyes; integument smooth, densely covered with short and fine yellow setae; frons short, vertex flat, occipital region convex, broadly rounded behind eyes. Clypeus flat, anterior margin emarginate, slightly projected anteriorly with median incision. Eyes small, rounded, prominent. Mandibles falciform, acute, without accessory teeth. Last maxillary and labial palpomeres securiform. Antennae (Fig. 6I) slightly flattened dorsoventrally; antennomeres III-IX wider distally, subserrate; antennomeres IX-XI slightly narrower than preceding ones. Pronotum (Fig. 7I) variable, about 1.5 times as wide as long; usually, anterior margin slightly arched, almost straight in middle, anterior angles arched; lateral margins slightly sinuate, with deep notch at posterior third; sometimes lateral margins less sinuate and lateral notches shallow; integument smooth, densely covered with very fine yellow setae. Elytra long, each elytron 4.5 times as long as wide, almost parallel, wider at middle; integument coriaceous, densely covered with short and fine decumbent setae, and much longer thick erect setae. Legs slender, densely pubescent, covered with long and thick setae; tarsi flattened dorsoventrally, fourth tarsomere with transversal slit at base; anterior prothoracic tarsal claws (Fig. 9I) broadly lobed basally, lobe with truncate margin; posterior claws on meso-and metathoracic tarsal claws apparently split at apex, with fine protruding tooth slightly shorter than claws. Abdomen weakly sclerotised, coriaceous, densely covered with long setae; ventrite VI deeply notched at posterior margin, V-shaped, lateral apices arched; ventrite VII ( Fig. 10I) with broad lobes, internal and apical margins forming acute tip strongly projecting ventrally. Aedeagus (Fig. 13A-C) triangular, ventral wall of tegmen parallel at base and strongly narrowing apically, apex acute; fringe of long setae along lateral margins of tegmen dorsally; parameres robust, very long, sinuous, apices acute, convergent; median lobe short, membranous, partially retracted behind parameres; central sclerite very long and slender, curved dorsally.

Distribution
Brazil (São Paulo and Rio de Janeiro states) (Fig. 16). Diagnosis Similar to D. vanini sp. nov. by the last antennomeres orangish (Fig. 4A), but differs by the antennae shorter with longitudinal lines on the antennomeres IX-XI (Fig. 6J, U), the pronotum with lateral margins not elevated (Figs 7J, 8J), by the elongate elytra (Fig. 4A), and by the shape of ventrite VII of males (Fig. 10J) and the aedeagus (Fig. 13D-F). The single known male specimen of D. viridimontanum sp. nov. was fixed with an everted internal sac, which exacerbates the morphological comparison with other species.

Etymology
The specific epithet viridimontanum refers to the type locality of the species, Monte Verde (Minas Gerais state, Brazil), which translates to 'green hill' from Portuguese. Paratype BRAZIL • 1 ♀; same collection data as for holotype; 2 Feb. 1970; MZSP 46484.

Description
Body length: 10.4 mm. Coloration (Fig. 4A): head pitch black, lustrous, except in lateral corners of clypeus, light brown; mandibles light brown, darker at base and tip; maxillary and labial palpi dark brown to black, light brown at apex of last palpomeres; antennae black, except antennomeres IX-XI and apex of VIII, orangish. Pronotum (Figs 7J, 8J) lustrous, partly translucent, with broad irregular black band from anterior to posterior margin, wider anteriorly and near posterior margin, and narrower near anterior half; background pale yellow with barely diffuse orange patches. Scutellum and elytra pitch black, slightly lustrous; at mid-length of each elytron, rounded whitish spot nearly reaching lateral borders but not meeting at suture. Thorax, legs and abdomen dark brown to black, tarsal claws brown. (Fig. 4A) Head short, nearly as long as wide, excluding eyes; integument smooth, densely covered with short and fine yellow setae; frons short, vertex flat, occipital region convex, broadly rounded behind eyes. Clypeus flat, anterior margin emarginate, slightly projected anteriorly with median incision. Eyes large, rounded, prominent. Mandibles falciform, acute, without accessory teeth. Last maxillary and labial palpomeres securiform. Antennae (Fig. 6J) short, slightly flattened dorsoventrally; antennomeres III-IX narrowing proximally, sub-serrate; antennomeres IX-XI with longitudinal lines dorsally. Pronotum (Fig. 7J) wide, about 1.4 times as wide as long; anterior margin and anterior angles arched; lateral margins slightly sinuate, with shallow notch at posterior third; anterior, posterior and lateral margins not elevated; integument smooth, densely covered with very fine yellow setae. Elytra very long, each elytron 5.7 times as long as wide, almost parallel; integument coriaceous, densely covered with short and fine decumbent setae, and much longer thick erect setae. Legs slender, densely pubescent, covered with long and thick setae; tarsi flattened dorsoventrally, fourth tarsomere with a transversal slit at base; anterior prothoracic tarsal claws (Fig. 9J) broadly lobed basally, lobe with very broad rounded margin; posterior claws on meso-and metathoracic tarsal claws apparently split at apex, with fine protruding tooth slightly shorter than claws. Abdomen weakly sclerotised, coriaceous, densely covered with long setae; ventrite VI notched at posterior margin; ventrite VII ( Fig. 10J) with triangular lobes, inner margins  nearly parallel, outer margins convergent posteriorly, apical margins rounded, with tip directed internally. Aedeagus (Fig. 13D-F): ventral wall of tegmen elongate, lateral margins convergent from apical third; apex forming a pair of short, rounded lobes with central acute tip curved ventrally; fringe of long setae along the lateral margins of tegmen dorsally; parameres very short, hidden between tegmen and median lobe; median lobe membranous, with numerous spine-like sclerites and tufts of thick pubescence.

Re-description
Body length: 13.0 mm. Coloration (Fig. 4B): head black, lustrous, except in lateral corners of clypeus, orangish; mandibles testaceous at base, gradually darker apicad; maxillary and labial palpi black, light brown at apex of last palpomeres; antennae entirely black. Pronotum (Fig. 7K) lustrous, partly translucent, with broad irregular dark brown to black band from anterior to posterior margin, wider anteriorly and near posterior margin, and narrower near anterior half; background pale yellow with diffuse orange patches. Scutellum and elytra dark brown to black, slightly lustrous; at mid-length of each elytron, long, irregular yellow to orangish spot extending from lateral borders to suture. Thorax, legs and abdomen dark brown to black, tarsal claws brown.
Male (Fig. 4B) Head short, nearly as long as wide, excluding eyes; integument smooth, densely covered with short and fine yellow setae; frons short, vertex flat, occipital region convex, broadly rounded behind eyes. Clypeus flat, anterior margin emarginate, slightly projected anteriorly with median incision. Eyes large, rounded, prominent. Mandibles falciform, acute, without accessory teeth. Last maxillary and labial palpomeres securiform. Antennae (Fig. 6K) long, distinctly flattened dorsoventrally; antennomeres III-IX slightly narrowing proximally, sub-serrate; antennomeres VIII-XI with longitudinal lines dorsally. Pronotum (Fig. 7K) wide, about 1.3 times as wide as long; anterior margin and anterior angles arched; lateral margins nearly parallel anteriorly, with rounded lobe, followed by deep notch at posterior third and broadly rounded lobe posteriorly; anterior, posterior and lateral margins elevated; integument smooth, densely covered with very fine yellow and black setae. Elytra very long, each elytron 5.5 times as long as wide, almost parallel; integument coriaceous, densely covered with short and fine decumbent setae, and much longer thick erect setae. Legs densely pubescent, covered with long and thick setae; fore leg slender; mid femur slightly arcuate at base and swollen at apex, mid tibia curved at apex; hind leg ( Fig. 9L) strongly modified, coxa with strong unciform projection, trochanter oblong, femur strongly curved and swollen, narrower proximally, tibia widened and flattened distally; all tarsi flattened dorsoventrally, fourth tarsomere with transversal slit at base; anterior prothoracic tarsal claws (Fig. 9K) broadly lobed basally, lobe with very broad rounded margin; posterior claws on meso-and metathoracic tarsal claws apparently split at apex, with fine protruding tooth slightly shorter than claws. Abdomen weakly sclerotised, especially at middle of the ventrites, coriaceous, densely covered with long setae; ventrite VI notched at posterior margin, U-shaped; ventrite VII (Fig. 10K) strongly notched at inner margins, exposing part of aedeagus, inside densely covered with thick and long yellow setae, brush-like, outer margins arched posteriorly, apical margins acute, with tip directed internally. Aedeagus (Fig. 13G-J) partly exposed between halves of ventrite VII; ventral wall of tegmen short and broad, with elongate central projection curved dorsally; lateral margins of ventral wall rounded and divergent, with long and thick setae on distal margin and inside; central projection parallel and with a pair of longitudinal ridges proximally, and widened, flattened, with small triangular spine distally, apex with longitudinal slit; parameres short and stout, apex truncate; median lobe short, membranous, with a pair of strong triangular dorsal sclerites and brush-like projections laterally and ventrally.

Female
Unknown.

Diagnosis
Distinguished from the other species by the elytra black with unclearly defined lighter spots and the legs reddish brown with black tarsi (Fig. 4D, F).

Type material
Syntypes (

Re-description
Body length: 12.0 mm. Coloration: head black, lustrous, except in lateral corners of clypeus, orangish; maxillary palpi dark brown; antennomeres I-VIII dark brown, IX-XI orangish. Pronotum (Fig. 8K) lustrous, with broad irregular black band from anterior to posterior margin, wider anteriorly and near posterior margin, and narrower near anterior half; background testaceous with diffuse orange patches. Scutellum and elytra black, slightly lustrous; at mid-length of each elytron, small and weakly defined round yellowish spot near lateral margins. Legs reddish brown, tarsomeres II-V black. Male  Head short, nearly as long as wide, excluding eyes; integument smooth, densely covered with short and fine setae; frons short. Eyes large, rounded, prominent. Last maxillary palpomeres securiform. Antennae long, probably reaching the middle of elytra, slightly flattened dorsoventrally; antennomeres III-IX slightly narrowing proximally, sub-serrate. Pronotum wide, about 1.5 times as wide as long; anterior margin and anterior angles broadly arched; lateral margins sinuate broader posteriorly; anterior, posterior and lateral margins elevated; integument smooth, densely covered with very fine setae. Elytra long, each elytron 5 times as long as wide, nearly parallel; integument coriaceous, densely covered with short and fine decumbent setae, and much longer thick erect setae. Legs slender, densely pubescent, covered with long and thick setae; tarsi flattened dorsoventrally, fourth tarsomere with transversal slit at base. Aedeagus : ventral wall of tegmen elongate, lateral margins convergent from apical third; apex forming a pair of short, rounded lobes with central acute tip curved ventrally; fringe of long setae along lateral margins of tegmen dorsally; parameres very short, hidden between tegmen and median lobe; median lobe membranous, with numerous spine-like sclerites and tufts of thick pubescence.

Female
Similar to male; pronotum (Fig. 8K) wider, lateral margins without notches; tarsal claws without basal lobe or apical slit; ventrite VII ( Fig. 15K) broad, lateral and distal margins broadly arched, distal margin with two apical rounded lobes projecting posteriorly at middle.

Remarks
This taxon was described as a variety ("v.") of D. albonotatum by Pic (1930). Pic did not specify the number of specimens examined, but he stated that they were "ex Hicker", i.e., from the collection of his contemporary Richard Hicker . Hicker's Cantharidae collection was acquired by Walter Wittmer and is now at NHMB. Two specimens matching Pic's description were found there. A female from "Rio Grande do Sul" labelled as coming from R. Hicker's collection and a male with a handwritten label by Zikan from W. Wittmer's collection, which was likely acquired by W. Wittmer via R. Hicker and is therefore here included as a syntype. During a visit at MNHN, and on photos of M. Pic's Discodon boxes kindly provided by R. Constantin, no specimen attributable to D. testaceipes was found. The name D. albonotatum testaceipes is here treated as subspecific and available in accordance with ICZN Art. 45.6.4, as it is currently widely practised for names described as "var." by this author. But based on the differences outlined above, we conclude that it should be treated as a full species (stat. nov.).

Key to the species of D. tricolor mimetic complex
Several species in different beetle families from the Atlantic Forest biome in Brazil show a similar colour pattern with a black body and elytra, a pronotum with orange lateral margins, and white to orangish elytral spots (Fig. 17). This identification key distinguishes cantharid species with such a colour pattern, as well as similar species with entirely black elytra. Included in the key is the cantharid species Chauliognathus fenestratus (Perty, 1830) ( Fig. 17A) which, despite belonging to a different subfamily (Chauliognathinae), is sympatric and may easily be confounded with species of D. tricolor mimetic complex.

Species and morphological diversity in Discodon
Discodon includes nearly 400 species distributed in the continental Americas, from southern USA to Argentina, except in Chile (Delkeskamp 1977). The genus represents a wide range of morphologically different assemblages of species throughout its distribution range. In its original description, Gorham (1881) diagnosed the genus based on males, especially as having the sides of the pronotum with a small notch (e.g., Fig. 7), the last ventrite deeply divided into two halves (e.g., Fig. 10), and the anterior tarsal claw of the protarsus with a broad basal lobe (e.g., Fig. 9). Although these diagnostic features are rather constant in the genus, the species greatly differ when other characters of both males and females are thoroughly explored.
Despite this broad morphological diversity, only three subgenera were proposed in the attempt to reunite morphologically similar species: Falsopolemius Pic, 1928, with nine species, and the monotypic Mathanosilis Pic, 1955 and Acanthodiscodon. Considering the current broad morphological concept of Discodon, it makes no sense to maintain a separate monotypic subgenus for a single species that falls well within the range of the morphological diversity of Discodon s. str. Thus, Acanthodiscodon is herein synonymised with Discodon. We acknowledge, however, that future studies may eventually require the restitution of Acanthodiscodon and the erection of new genera and subgenera to accommodate other species currently identified as Discodon. However, when compared to the global diversity of Discodon, the number of species studied here is still insignificant to justify the erection of new genera, subgenera or species groups.
Some of the species studied here show a rather constant set of characters that may indicate a close phylogenetic relationship. For instance, D. tricolor, D. neuteutonum sp. nov., D. vanini sp. nov. and D. obscurior stat. nov. have similar small aedeagi, with the ventral wall of the tegmen short, slightly narrowing distally, and the apex bilobed with a median incision and a small tip pointing ventrally ( Fig. 11A-L); the protarsal claws of the males have an elongate basal lobe with a sinuous margin (Fig. 9A-D); the distal margin of ventrite VII of females has two lateral lobes and a slight central round projection (Fig. 15A-D); and ventrite VII of males has sinuous margins ( Fig. 10A-D). In contrast, D. lineaticorne sp. nov., D. aurimaculatum sp. nov., D. marginicolle sp. nov. and D. tenuecostatum sp. nov. have the aedeagus large, with the ventral wall of the tegmen elongate, the distal margin with three strong projections and the central projection strongly curved ventrally; the protarsal claws of males have a broad basal lobe with arched margin (Fig. 9E-H); and ventrite VII of females usually broadly arched laterally and the apex with two projecting tips and a central rounded notch (Fig. 15E-F, H). Other species have a combination of these or different features, like the presence of antennal lines in males of D. lineaticorne, D. crassipes and D. marginicolle sp. nov. (Fig. 6E, G, K), a central projection of the ventral wall of the tegmen with a flat ventral plaque in D. crassipes and D. tenuecostatum sp. nov. (Figs 12M,  13J), and ventrite VII of females broadly arched, without lobes or projections in D. viridimontanum sp. nov. (Fig. 15J), among others.
The shape and distribution of the antennal lines are important diagnostic characters in Amazonian species of Discodon and Pygodiscodon Wittmer, 1966(Constantin 2015Biffi & Constantin 2018), but they are absent in most of the species of Discodon from the Atlantic Forest biome. Other characters that may be important in morphological comparisons include the shape of the pronotum, the general body pubescence, the presence of elytral costae, the shape and compression of the antennomeres and the shape of the last tergite of males. Our study does show that the morphology of some structures is similar between some species and, at the same time, rather different from others. The recognition of new genera and a subdivision of Discodon into subgenera or species groups might eventually be necessary when the species diversity and phylogenetic relationships of Discodon are assessed.

Notes on mimicry
As discussed above, despite their striking similarities in colour pattern, size and habitus, the 13 species discussed herein do not seem to be part of the same monophyletic clade within Discodon. This opens up the question as to whether this particular 'habitus' has an evolutionary advantage for cantharids living in the Atlantic Forest biome. Outside of the genus Discodon, a very similar colour pattern and habitus can also be found in Chauliognathus fenestratus (Perty, 1830) (Cantharidae: Chauliognathinae), at least two Lampyridae Latreille, 1817 of the subfamily Photurinae Lacordaire, 1857 (Bicellonycha sp. and Pyrogaster sp.), and to some extent also in the Cerambycidae Ibitiruna fenestrata (Bates, 1881) and the weevil Homalocerus bimaculatus Vanin, 2014 (Belidae) (Fig. 17). All these species are roughly the same size as the Discodon discussed here and occur sympatrically. All of the Discodon discussed here also occur sympatrically with at least one other Discodon with a similar appearance, with the possible exception of D. neoteutonum sp. nov. A possible mimicry complex involving Homalocerus bimaculatus, Chauliognathus fenestratus and Discodon tricolor ('sensu lato') was first proposed by Vanin (2014). Our findings of an unexpectedly high number of similar-looking species of Discodon support the existence of a larger mimicry ring.
We do not have any precise information on chemical defences present within Discodon, Chauliognathus fenestratus or the two lampyrid species here. However, we can infer from related taxa that most, if not all of these species, share some kind of chemical defence and may therefore be Mullerian mimics. Chemical defences and aposematism are well documented in members of Chauliognathus (Meinwald et al. 1968;Eisner et al. 1981). A Mullerian mimicry ring involving another member of Silinae as well as Lycidae Laporte, 1836 was proposed as early as 1902, based on extensive feeding experiments involving birds and baboons (Marshall 1902;Darlington 1938). Potential mimicry between members of Lampyridae and some species of Discodon was noted by Champion (1915). Autohaemorrhaging ("reflex bleeding") behaviour is common among Neotropical Lampyridae and Lycidae (Eisner et al. 2008), and may occur in Silinae, albeit poorly documented.
For the time being, we suspect that the Discodon discussed here are likely to be Mullerian mimics, along with the Chauliognathus and the lampyrids, though this hypothesis needs further evidence. Ibitiruna fenestrata and Homalocerus bimaculatus are likely to be Batesian mimics, considering that many related members of their respective clades are (e.g., Vanin 1976;Nascimento et al. 2010). Furthermore, we have examined specimens of Ibitiruna fenestrata from the Atlantic Forest biome ranging from Rio de Janeiro to Santa Catarina states, from the same localities as the above-mentioned species of Discodon.
In each locality I. fenestrata shows variations in the pronotal and elytral patches that perfectly match their sympatric species of Discodon. These observations suggest that Ibitiruna fenestrata might easily mimic a specific Discodon model at each locality, or that I. fenestrata actually also comprises a complex of species with restricted distributions.

Species discovery amidst the rapidly vanishing Atlantic Forest
This work started with the recognition of certain morphological and chromatic variation in specimens of D. tricolor from collections and from photographic records on the online platform iNaturalist (Fig. 1). Such species, characterised by the black elytra with rounded whitish spots, the pronotum partly orangish and testaceous antennae, would eventually exhibit larger and angulate whitish elytral spots or entirely black elytra, and the antennae and pronotum partly or entirely black. The closer study of D. tricolor, their subspecies and similar sympatric species revealed the existence of a species complex comprising at least 12 different species, seven of which new to science. Most of the species were discovered mainly in a small portion of the Atlantic Forest in the area between the cities of São Paulo and Rio de Janeiro, and at some of the localities most frequently surveyed within the south-eastern Atlantic Forest, at the borders of São Paulo (SP), Rio de Janeiro (RJ) and Minas Gerais (MG) states, such as the Parque Nacional da Serra dos Órgãos (RJ), Parque Nacional do Itatiaia (RJ), Parque Estadual da Serra do Mar (MG, RJ, SP), Serra da Cantareira (SP) and Estação Biológica de Boracéia (SP) (Fig. 16).
The discovery of such a high number of new species from a single species initially investigated (D. tricolor) and from a relatively small portion of the Atlantic Forest implies that the real diversity of Discodon might be enormously higher than presently known and is still hidden across the whole biome range. It is not surprising that new species are discovered from species thought to be highly variable.
Biffi & Geiser (2020) described six new species of Peltariosilis Wittmer, 1952 after revising one single species supposedly variable and broadly distributed in the Amazon Forest. Thus, it is expected that substantially more new cantharid species might be discovered as other species complexes are thoroughly investigated and broader areas of the Atlantic Forest are explored.
The Neotropical Atlantic Forest is an extremely heterogeneous biome composed of numerous vegetation types, such as evergreen to semi-deciduous forests, deciduous forests, mangroves, swamps, coastal forest and scrub on sandy soils, inselbergs, high-altitude grasslands, and mixed Araucaria pine forests, which led to outstanding levels of endemism and species richness (Ribeiro et al. 2009(Ribeiro et al. , 2011. The original coverage of the Atlantic Forest is estimated at ca 150 million km 2 , ranging along the Brazilian Atlantic coast and extended westward into smaller, inland areas of Paraguay and Argentina (Ribeiro et al. 2009). The agricultural, urban and industrial expansion have profoundly affected the Atlantic Forest, which is now confined to only small, often disconnected fragments, representing about 11-16% of the original coverage (Ribeiro et al. 2009), with the most optimistic estimates revealing a current vegetation cover of 28%, or 32 million hectares of native vegetation (Rezende et al. 2018). Despite the large area of original coverage, with a broadly diversified mosaic of habitats, the knowledge on the diversity in this biome is uneven across its range, with studies and sampling usually restricted to few protected, easy-toaccess and popular localities, leaving most portions of the remaining Atlantic Forest poorly explored or completely unsampled.
Given the rapid rate of deforestation and destruction of natural habitats, with the consequent loss of biodiversity, and the predictions of future extinctions (Gonçalves-Souza et al. 2020), there is an urgent need to step up efforts not only for conservation but also for documentation of the remaining Atlantic Forest biodiversity. Such research must be done as soon as possible, before some areas are completely destroyed and the species there are extinct. Discodon lineaticorne sp. nov. is a possible example of local extinction due to urban expansion. Four specimens were collected in the district of Ipiranga in 1908, then located in the outskirts of São Paulo city. Due to the immense urban sprawl, Ipiranga is now located in the middle of the metropolitan area, and no more specimens were collected there ever since.