Discodon Gorham, 1881

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 : 151

Genus Discodon Gorham, 1881

Discodon is a morphologically diverse and heterogeneous genus distributed all across the continental parts of the Neotropical region and into the south-western United States. Gorham (1881) characterised the genus based on males as having the sides of the pronotum with a small notch, the last ventrite deeply divided into two halves, and the anterior claw of the protarsus with a broad basal lobe. The males of other genera of Silinae occurring in the Atlantic forests of Brazil – Silis Charpentier, 1825 and Pachymesia Westwood, 1849 – differ from Discodon for having the pronotum much wider than long and the lateral margins deeply notched, with variously shaped spines and projections, the anterior tarsal claw of the protarsus with a small basal lobe, the other claws simple, and the antennae sometimes distinctly swollen ( Pachymesia ). Other species from the Atlantic Forests currently combined in Incisosilis Pic, 1908 , Polemius LeConte, 1851 , Parasilis Gorham, 1885 and Malthinocantharis Pic, 1914 might need to be transferred to the aforementioned genera. The widespread Neotropical genus Polemius LeConte, 1851 is primarily distinguished from Discodon by the meso- and metatarsal claws of the males, which have a basal lobe in Polemius , but are deeply cleft in Discodon ( Constantin 2017) , but the phylogenetic relevance of this character is yet to be proven for the Neotropical fauna.

The Discodon tricolor mimetic complex includes relatively large species (9.7–16.2 mm) characterised by the black body and legs, a similar orangish pattern on the pronotum and a pair of white to yellowish rounded or semi-circular spots in the middle of the elytra. It also includes some species with entirely black elytra that are here described as new species or have been treated as subspecies of D. tricolor .