Cercyon (Cercyon) praetextatus ( Say, 1825 )

Clarkson, Bruno, Mise, Kleber M. & Almeida, Lucia M., 2020, Cercyon Leach, 1817 (Coleoptera: Hydrophilidae: Sphaeridiinae) from Brazil: new species and records, Revista Brasileira de Entomologia (e 201972) 64 (1), pp. 1-8 : 7

Cercyon (Cercyon) praetextatus ( Say, 1825)

Sphaeridium praetextatum Say, 1825: 190 .

Cercyon praetextatum (Say) : Melsheimer, 1853: 37.

For complete synonymy see Smetana (1978) and Hansen (1999).

Material examined: BRAZIL: Paraná: Colombo : “ COLOMBO - PR / EMBRAPA BR 476 km 20/ BRASIL 30. I. 1987 / Lev. Ent. PROFAUPAR/ LÂMPADA” (1 ex.: DZUP); Guarapuava: “Guarapuava - Paraná / Est. Águas Sta. Clara/ BRAZIL 02. XII.1986 / Lev.Ent. PROFAUPAR/ LÂMPADA” (2 exs.: DZUP); same data, different dates, all specimens deposited in DZUP: “ 03. XII. 1986 ” (1 ex.); “ 31.XII.1986 ” (1 ex.); “ 27.I.1987 ” (1 ex.); “ 28.I.1987 ” (1 ex.); “ 31. I.1987 ” (1 ex.); “ 26.II.1987 ” (1 ex.); “ 27.III.1987 ” (1 ex.); Fênix: “FÊNIX - PARANÁ / Reserva Est - ITCF/ BRASIL 27.I.1987 / Lev. Ent. PROFAUPAR/ LÂMPADA” (1 ex.: DZUP); same data, different date: “ 29.III.1987 ” (1 ex.: DZUP); Jundiaí do Sul : “JUNDIAÍ DO SUL - PR / Fazenda Monte Verde/ BRASIL 30. XI. 1986 / Lev. Ent. PROFAUPAR/ LÂMPADA” (3 ex.: DZUP); same data, different dates, all specimens deposited in DZUP: “ 01. I. 1987 ” (2 exs.); “ 28. II. 1987 ” (1 ex.); 31.III. 1987 ” (1 ex.); Telêmaco Borba : “TELÊMACO BORBA - PR / Res. Samuel Klabin/ BRASIL 31. XII. 1986 / Lev. Ent. PROFAUPAR/ LÂMPADA” (2 exs.: DZUP); same data, different dates, all specimens deposited in DZUP: “ 27. I. 1987 ” (1 ex.); “ 01. III. 1987 ” (1 exs.); “ 25. II. 1987 ” (1 exs.).

Discussion. This species is widely distributed in North and Central America – with occurrence in Canada, USA, Mexico, Guatemala, Costa Rica, Cayman Islands, Cuba, Dominican Republic and Jamaica ( Smetana, 1978; Hansen, 1999; Arriaga-Varela et al., 2017). Cercyon praetextatus was recorded as introduced in Argentina by d’Orchymont (1939) based on specimens collected around Buenos Aires (Tigre). Fikácek (2009) confirmed the occurrence and the hypothesis that the species is introduced in Argentina based on specimens from Entre Rios Province (Colón). The author pointed out that the species seems likely to be native in the northern part of the Neotropical Region. Cercyon praetextatus is herein recorded for the very first time in Brazil as a widely distributed species in Paraná State. According to this distribution, seems likely the species was introduced in the “Southern Cone” of Latin America but we cannot rule out the possibility of a natural wide distribution in the New World, since Sphaeridiinae have been neglected in South American biodiversity studies and the missing of records of Cercyon throughout the continent may be consequence of the lacking of collecting and taxonomic works focused in the group.

The species is easily recognizable by the moderate small size (body length 2.4–4.1 mm); dorsal coloration with head dark-brown to black, pronotum dark-brown to black (in all examined specimens) sometimes with sharply defined yellowish to reddish areas at anterolateral corners or at lateral margins ( Smetana, 1978; Arriaga-Varela et al., 2017), elytra dark-brown to black with large sharply-defined yellowish to reddish-yellow lateroapical area reaching about apical fourth, laterally reaching elytral base in lateralmost interval, yellow spot not extended to humeral area basally; medial ridge of prosternum anteriorly forming a small rounded to slightly pointed process; mesoventral plate wide (ca. 3× as long as wide); and the conspicuous male genitalia. For more detailed information on the morphology and illustrations of the species see Smetana (1978) and Arriaga-Varela et al. (2017).

Bionomics. All the examined specimens were collected with light traps but according to with Smetana (1978) the species seems to prefer primarily wet environments (such as edges of lakes and streams, marshes, wet deciduous forests, etc.) and can be found on many kinds of organic debris, leaf-litter, decomposing plant remnants, carrion, and dung.