Discodon crassipes Wittmer, 1952

Biffi, Gabriel & Geiser, Michael, 2022, A revision of Discodon tricolor (Guérin-Méneville) and its mimics from the Atlantic forests of Brazil (Coleoptera: Cantharidae), European Journal of Taxonomy 834 (1), pp. 148-189 : 176-179

Discodon crassipes Wittmer, 1952

Figs 4B–C, 6K, 7K, 9K–L, 10K, 13G–J

Discodon (Acanthodiscodon) crassipes Wittmer, 1952: 200 .

Discodon (Acanthodiscodon) crassipes – Delkeskamp 1977: 260 (catalogue).

Diagnosis

Species readily distinguished by the strong modifications on the metathoracic legs ( Figs 4B, 9L), the shape of the pronotum ( Fig. 7K), ventrite VII of the male ( Fig. 10K) and the aedeagus ( Fig. 13G–J).

Type material

Holotype

BRAZIL • ♂; [Rio de Janeiro, Parque Nacional da] Serra dos Órgãos; 1200 m a.s.l.; 5 Feb. 1952; NHMB CANTH00019527 ( Fig. 4B–C).

Paratype

BRAZIL • ♂; same collection data as for holotype; NHMB .

Other material examined (1 specimen)

BRAZIL • 1 ♂; Rio de Janeiro, Teresópolis ; 13–16 Dec. 1957; Seabra and Alvarenga leg.; DZUP 376213 .

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.

Distribution

Brazil (Rio de Janeiro state) ( Fig. 16).

Remarks

Wittmer (1952) erected the subgenus Acanthodiscodon to include the single species D. (A.) crassipes , defined by the strong modifications in the hind legs. Given the vast morphological variation seen in Neotropical species of Discodon , especially in the aedeagus structures, it is not justifiable to separate a single species D. crassipes in its own subgenus Acanthodiscodon , which is herein synonymised with Discodon (syn. nov.).