Cercyon praetextatus (Say, 1825)

Arriaga-Varela, Emmanuel, Seidel, Matthias, Deler-Hernandez, Albert, Viktor Senderov, & Fikacek, Martin, 2017, A review of the Cercyon Leach (Coleoptera, Hydrophilidae, Sphaeridiinae) of the Greater Antilles, ZooKeys 681, pp. 39-93 : 52-53

Cercyon praetextatus (Say, 1825) Figures 2 g–i, 6 a–d, 13 a–b, 15c

Sphaeridium praetextatum Say, 1825: 190.

Cercyon praetextatum (Say): Melsheimer, 1853: 37. For complete synonymy see Smetana (1978: 84) and Hansen (1999: 286).

Figures in Flickr.

www.flickr.com/photos/142655814@N07/albums/72157669492876764

Type locality.

USA, “Cambridge” (based on neotype designated by Smetana 1978).

Greater Antillean specimens studied. CUBA: Santiago de Cuba: Dos Caminos, farm field, MV lights, 20.18043°N, 75.77806°W, 165 m, 23.iii.2013, leg. A. Smith & A. Deler-Hernández (1 spec.: NMPC). Cienfuegos: Cumanayagua municipality, JBC [= Jardín Botánico de Cienfuegos], Soledad, 22°7'18.44"N, 80°19'35.26"W, 3.x.2012, leg. A. Deler-Hernández (1 spec.: NMPC). CAYMAN ISLANDS: Grand Cayman: black-light trap, 17.v.1992, leg. P. Fitzgerald (1 spec.: FSCA). DOMINICAN REPUBLIC: La Vega Prov.: Jarabacoa, 440 m a.s.l., riverside, UV light, 24.vii.-2.viii.1995, leg. S. & J. Peck (3 spec.: CMN). La Ciénega de Manabao, Park Headquarters, 915 m a.s.l. black-light, 3-5.vii.1999, leg. R.E. Woodruff (1 spec.: FSCA).

Published Greater Antillean records.

CUBA: Habana Province: Laguna de Ariguanabo ( Spangler 1981). JAMAICA: without precise locality ( Smetana 1978).

Diagnosis.

Body size 2.7-4.1 mm; dorsal surface of head (Fig. 2g) black, with a pair of small reddish-brown spots on vertex, sometimes fused to one spot; pronotum black with sharply defined yellowish to reddish areas at anterolateral corners, some times extending to complete lateral margins; elytra 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 (Fig. 13a) wide, ca. 3.3 × as long as wide; metaventrite (Fig. 13b) without femoral lines, with narrow raised pentagonal area (ca. as long as wide); first abdominal ventrite without spiniform process in both sexes; apex of fifth ventrite without triangularly bulged projection at apex in both sexes; aedeagus (Fig. 6 a–c) with parameres almost twice as long as phallobase, sinuately widened and bearing long setae at apex; median lobe widest at midlegth, narrowing to pointed apex, without spines. For complete description see Smetana (1978).

This species was assigned to the C. marinus group according to Smetana (1978). By the coloration of pronotum and elytra (Fig. 2g, i), C. praetextatus may be confused with members of the C. gimmeli species group and with C. sklodowskae sp. n. Besides of the features of the aedeagus (Fig. 6 a–c), it can be easily distinguished from them by the distinctly wider mesoventral plate (3.3 × as long as wide in C. praetextatus , 5.7 –5.8× as long as wide in the other species) and the yellow stripe along lateral margin of elytra not expanding basally. Besides of that, females of C. praetextatus lack the triangular projection on the apex of the fifth abdominal ventrite (present in C. sklodowskae ), has a very small process of mid-prosternal ridge (large in C. gimmeli species group), and almost straight metatibia (curved in C. gimmeli species group).

Distribution.

Cercyon praetextatus is widely distributed in North America (southern Canada, USA, Mexico; Smetana 1978; Ryndevich 2004) and reaches to Central America (Guatemala, Costa Rica; Smetana 1978) and to the Caribbean (Cayman Islands, Cuba, Dominican Republic, Jamaica, Smetana 1978, Spangler 1981, this paper); it has also been introduced to Argentina ( Fikáček 2009). We report it here from Dominican Republic (La Vega Province) and the Cayman Islands for the first time (Fig. 15c).

Biology.

This species seems to prefer wet environments, living primarily on many kind of organic debris, like decomposing plant remnants, carrion and dung ( Smetana 1978). In Cuba and the Dominican Republic this species has been attracted to light.