Platysaprinus Bickhardt, 1916

Lackner, Tomáš & Arriagada, Gerardo, 2020, Revision of Euspilotus, subgenus Platysaprinus, with description of two new species (Coleoptera: Histeridae), Acta Entomologica Musei Nationalis Pragae 60 (1), pp. 303-317 : 304-305

Subgenus Platysaprinus Bickhardt, 1916

Platysaprinus: BI CKHARDT (1914): 306 (nomen nudum).

Platysaprinus Bickhardt,1916: 106 (original description).BLA CKWELDER (1944): 180 (catalogue).

Euspilotus (Platysaprinus) : MAZUR (1984):72 (catalogue); MAZUR (1997): 239 (catalogue); MAZUR (2011): 192 (catalogue).

Type species. Saprinus latimanus Schmidt, 1890 by original designation.

Diagnosis. Dark-brown, elongate-oval to broadly-oval non-metallic Saprininae beetles of small to moderate size, with reddish to brown-red body appendages. Frontal stria widely interrupted and prolonged onto clypeus. Lacinial uncus in at least one species (E. (P.) latimanus )) present; antennal scape (triangularly) dilated. Lateral pronotal stria complete and carinate in most species. Dorsal elytral striae 1–4 present, sutural elytral stria present or vaguely impressed to absent; elytral disc in most species with dense punctures. Apical elytral stria shortened to absent. Flanks of pygidium in one species keel-like. Prosternal process compressed, usually keel-like, apical prosternal stria present, in most cases connecting large prosternal foveae; both sets of prosternal striae usually present. Tibiae dilated and rather short. Apex of sternite VIII of male genitalia with a brush of tiny setae; tergite VIII usually outwardly arcuate; apex of spiculum gastrale usually gradually broadly dilated medio-apically. Aedeagus with rather short phallobase, in most species narrowing apically with pointed apex.

Differential diagnosis. Members of Platysaprinus differ from the rest of the Euspilotus chiefly in the dilated tibiae, especially the protibiae. Their non-metallic, entirely punctate upper body surface (with the exception of E. (P.) ferreri )), or non-maculate elytra can also distinguish them from their Neotropical congeners. Most, if not all members of Euspilotus from the South American continent are found on carrion, occasionally also in dung. Tn the contrary, Platysaprinus members are, as far as it is known, inquilines of ants. Tur current state of knowledge and the amount of undescribed South American Euspilotus prevent us from providing a more detailed differential diagnosis for the subgenus.

Biology. Euspilotus (Platysaprinus) myrmecophilus as well as Euspilotus (Platysaprinus) latimanus were collected in the nests of fungus growing ants of the genus Acromyrmex Mayr, 1865 ( Hymenoptera : Formicidae : Myrmicinae) (LA CKNER 2014 and the references therein). The two newly described species are of unknown biology; one of them was collected using flight interception traps (FIT).

Distribution. Argentina: Misiones; Bolivia; Brazil: Federal District, Paraná, Rio Grande do Sul, Mato Grosso, Minas Gerais, São Paulo; Paraguay: Amambay; Uruguay.

Key to species

1(2) Large species (PEL= 3.55–5.50 mm), first dorsal elytral stria keel-like, costate ( Fig. 1 ), lateral sides of pygidium costate ( Fig. 8 ). Argentina: Misiones; Bolivia; Brazil: Federal District, Mato Grosso, Minas Gerais, São Paulo; Paraguay: Amambay). ............... Euspilotus (P.) latimanus ( Schmidt, 1890)

2(1) Smaller species (PEL=2.10–4.00 mm), first dorsal elytral stria not keel-like ( Fig. 23 ), lateral sides of pygidium not costate.

3(4) Elytra on basal half impunctate ( Fig. 34 ). Brazil: Minas Gerais, Mato Grosso and Rio de Janeiro. ............. ............................... Euspilotus (P.) ferreri sp. nov.

4(3) Entire elytra densely punctate ( Figs 23 , 45).

5(6) Body elongate oval; dorsal elytral striae 3–4 abbreviated basally ( Fig. 45 ), smaller species (PEL=2.10– 2.30). Brazil: Mato Grosso. ........................................... ........................... Euspilotus (P.) vazdemelloi sp. nov.

6(5) Body broadly oval; dorsal elytral striae 3–4 almost reach elytral base ( Fig. 23 ), larger species (PEL=3.00– 4.00 mm). Argentina, Brazil, and Uruguay. ............... .... Euspilotus (P.) myrmecophilus ( Bickhardt, 1910)

Figures

Figs 1–2. Euspilotus (Platysaprinus) latimanus (Schmidt, 1890). 1 – habitus, dorsal view; 2 – ditto, ventral view.

Figs 8–13. Euspilotus (Platysaprinus) latimanus (Schmidt, 1890). 8 – pygidium; 9 – prosternum; 10 – mesoventrite; 11 – lateral disc of metaventrite G metepisternum; 12 – protibia, dorsal view; 13 – ditto, ventral view.

Figs 23–24. Euspilotus (Platysaprinus) myrmecophilus (Bickhardt, 1910). 23 –habitus, dorsal view (on the photo is the holotype of Saprinus carinipennis Desbordes, 1924); 24 – prosternum, meso- and metaventrite.

Figs 34–35. Euspilotus (Platysaprinus) ferreri sp. nov. 34 – habitus, dorsal view; 35 – prosternum, meso- and metaventrite.

Figs 45–46. Euspilotus (Platysaprinus) vazdemelloi sp. nov. 45 – habitus, dorsal view; 46 – prosternum, meso- and metaventrite.