Cercyon insulare Cercyon insulare A review of the Cercyon Leach (Coleoptera, Hydrophilidae, Sphaeridiinae) of the Greater Antilles Arriaga-Varela, Emmanuel Seidel, Matthias Deler-Hernandez, Albert Viktor Senderov, Fikacek, Martin ZooKeys 2017 681 39 93 SVY3 Chevrolat, 1863 Chevrolat 1863 Insecta Hydrophilidae Cercyon CoL Animalia Cercyon insularis Coleoptera 18 57 Arthropoda species insularis   Cercyon insulareChevrolat, 1863: 208.  Cercyon insulare Gundlach (1891: 50, redescription).  DNA barcodes. GANTC001-16, GANTC011-17, GANTC012-17  BIN ID. BOLD:ADC9388.  Figures in Flickr. www.flickr.com/photos/142655814@N07/albums/72157669492393134  Type locality. Cuba: Havana.  Type material. Holotype (unsexed specimen): "Havana, D. Poey // Cercyon insulare, Chev Cuba, [illegible] // TYPE [red label]" (MNHN).  Figure 4. Cercyon insularisChevrolat and C. variegatusSharp. a-i C. insularis: a-cdorsal, ventral and lateral habitus of the non-type specimen from Cuba d habitus of the holotype e labels of the holotype f-imale genitalia of non-type specimen from Dominican Republic. j-olectotype of C. variegatus: j dorsal habitus k labels l-omale genitalia. Genital parts illustrated: f, l tegmen of aedeagus g, m median lobe of aedeagus h, n detail of apex of median lobe; i, o 9th sternite.  Figure 5. Cercyonspp. n. genitalia a-d Cercyon gimmelisp. n. e-h Cercyon tainosp. n. i-l Cercyon armatipenissp. n. m-p Cercyon sklodowskaesp. n. a, e, i, m tegmen of aedeagus b, f, j, n median lobe of aedeagus c, g, k, o 9th sternite.  Figure 6. Cercyonspp. n. genitalia a-d Cercyon praetextatusSay e-h Cercyon spiniventrissp. n. i-k Cercyon nigricepsMarsham l-n Cercyon quisquiliusLinnaeus a, e, i, l tegmen of aedeagus b, f, j, m median lobe of aedeagus c, g 9th sternite.  Figure 7. Cercyon floridanusHorn a tegmen of aedeagus b median lobe of aedeagus c 9th sternite d ventral view of pterothorax.  Additional material examined. CUBA: Camagueey: Sierra de Cubitas municipality, Limones-Tuabaquey, 21°35'52.10"N, 77°47'17.62"W, 16.v.2013, leg. R. Anderson (1 spec.: NMPC). Guantanamo: El Yunque, 3.2 km SW of campismo popular, at right tributary of Duabe river, secondary evergreen forest, cow excrement, 20°19'N, 74°34'W, 150 m a.s.l., 13.vi.2012, leg. Deler-Hernandez& Fikacek(MF09) (7 spec.: NMPC); El Yunque, ca. 1.4 km W of campismo popular, cocoa plantations shaded by palms, cow excrement, 20°20.2'N, 74°33.7'W, 60-150 m a.s.l., 11.vi.2012, Deler-Hernandez& Fikacek(MF03) (16 spec.: NMPC). Santiago de Cuba: El Vivero, 1.6 km E of Dos Caminos, cow excrements on pasture, 20°10.8'N, 75°46.4'W, 150 m, 20-21.vi.2012, leg. Deler-Hernandez& Fikacek(MF18) (1 spec.: NMPC); San Luis Municipality, Dos Caminos, 20°10'57.82"N, 75°46'40.84"W, 3.x.2012, leg. Deler-Hernandez(12 spec.: NMPC). Granma: PN Turquino, around La Platica, 20°0.7'N, 76°53.4'W, 880 m, 25-26.vi.2012, leg. Deler-Hernandez& Fikacek(MF24) (12 spec.: NMPC); PN Turquino, on the trail up to 0.5 km S of La Platica, 20°0.5'N, 76°53.3'W, 920 m, 23-27.vi.2012, leg. Deler-Hernandez& Fikacek(MF20) (2 spec.: NMPC); PN Turquino, La Siguapa, ca. 1.5 km SE of La Platica, sifting leaf litter in evergreen forest, 20°0.2'N, 76°52.8'W, 1290 m, 25.vi.2012, leg. F. Cala-Riquelme (MF25) (1 spec.: NMPC) [DNA extract at NMPC] (1: NMPC). Artemisa: Canonde Santa Cruz, Riode Santa Cruz, 22°45'1.29"N 83°08'56.36"W, 199 m a.s.l., 16.vii.2016, leg. A. Deler-Hernandez(1 spec.: NMPC) [DNA extraction: MF1749]. DOMINICAN REPUBLIC: La Vega: 7.0 km W of Manabao, side of a stony stream in a valley with scattered houses and plantations surrounded by montane forest, in cow excrements, 19°4.56'N, 70°51.46'W, 1185 m a.s.l., 23.viii.2014, leg. Deler-Hernandez, Fikacek& Gimmel (DR18) (3 spec.: NMPC); at S margin of Manabao, 19°3.85'N, 70°47.61'W, 912 m a.s.l., 27.viii.2014, leg. Deler-Hernandez& Fikacek(DR23) (3 spec.: NMPC). Samana: MN Salto El Limon2.8 km SSW of El Limon, secondary vegetation and tiny remnants of forests among coffee plantations and pastures, cow excrements, 19°16.56'N, 69°26.47'W, 2.ix.2014, leg. Deler-Hernandez, Fikacek& Gimmel (DR29a) (16 spec.: NMPC). MonsenorNouel: PN La Humeadora; 11.6 km SSW, of Piedra Blanca, in horse excrement in moist broad-leaf forest in a valley of a small stony stream, 18°44.92'N, 70°21.63'W, 636 m a.s.l., 8.ix.2014, leg. Deler, Fikacek& Gimmel (DR41) (4 spec.: NMPC) [DNA extracts: MF1214.1, MF1214.2]. PUERTO RICO: Naguabo: El Yunque National Forest (southern part), 3.45 km N of RioBlanco at road PR191, in horse excrements on exposed small pasture on the slope of El Yunque massive, 18°14.8'N, 65°47.9'W, 170m a.s.l., 24.vi.2016, leg. Deler-Hernandez, Fikacek& Seidel (PR2a) (19 spec.: NMPC) [DNA extraction: MF1731]; El Yunque National Forest (southern part), 4.9 km N iof RioBlanco, margin of the rainforest in an area with many flowering Etlingera elatiorplants, FIT, 18°15.8'N, 65°47.3'W, 495 m a.s.l., 24.vi.-2.vii.2016, leg. Fikacek& Seidel (PR11) (3 spec.: NMPC). Arecibo: small settlement in Bosque Estatal RioAbajo, in the middle of the lowland forest, horse excrement, 18°19.7'N, 66°42.1'W, 340 m a.s.l., 27.vi.2016, leg. Deler-Hernandez, Fikacek& Seidel (PR15) (1 spec.: NMPC). Lesser Antilles: DOMINICA: Springfield Estate, mature secondary forest, FIT, 15°20.796'N, 61°22.142'W, 30.v.-16.vi.2004, S. & J. Peck (04-86) (3 spec.: SBP). GRENADA: Grand Etang Forest Reserve, FIT in rainforest, 12°04.846'N 61°42.333'W, 360 m a.s.l., leg. S. Peck (10-61) (2 spec.: SBP); Grand Etang Forest Reserve, FIT in rainforest, 12°04.162'N 61°42.162'W, 400 m a.s.l., leg. S. Peck (10-63) (2 spec.: SBP); St. Andrew, Mirabeu Agriculture Lab, light trap, 19.iv.1990, leg. J. Telesford (2 spec.: SBP). SAINT LUCIA: Mon Repos, 6.5 km W Fox Grove Inn, submontane forest, carrion traps, 13°52.5'N, 60°56.4'W, 300 m a.s.l., leg. S. & J. Peck (0759) (2 spec.: SBP).  Published records (as C. variegatus). JAMAICA: without precise locality ( Smetana 1978). PUERTO RICO: without precise locality ( Smetana 1978). DOMINICA: without precise locality ( Leng and Mutchler 1917; Peck 2006).  Diagnosis. Body size 2.4-3.4 mm; dorsal surface of head (Fig. 4a) black with a pair of small pale spots on vertex (sometimes fused in one central spot), pronotum yellowish to dark reddish-brown with a large blackish central spot and two small round blackish spots at sides (sometimes obscured); elytra yellowish with black humeral spot, in dark specimens whole elytral base and suture darkened; medial ridge of prosternum not projected ventrally (Fig. 12c); mesoventral plate narrow, 5.8 xas long as wide (Fig. 12f); metaventrite (Fig. 12g) without femoral lines, with raised pentagonal area as long as wide; first abdominal ventrite without spine-like process in both sexes (Fig. 12h); apex of fifth abdominal ventrite (Fig. 12i) without apical projection in both sexes; aedeagus narrow, parameres 0.7 xas long as phallobase (Fig. 4f), rounded at apex; median lobe (Fig. 4g) subparallel throughout except for acuminate apex, without subapical spines.  Redescription. Body. (Fig. 4 a-d) 2.4-3.4 mm long (length of holotype: 2.8 mm); moderately elongate oval, 1.7 -1.8xas long as wide, widest at basal fifth of elytra; moderately convex, 2.6 -2.8xas long as high (height of holotype: 1.0 mm). Coloration. Dorsal surface of head black with a pair of small rufotestaceous spots on vertex. Antennal scape and flagellum and ventral surface of head including mouthparts light-brown, antennal club and mentum dark brown. Pronotum yellowish to dark reddish-brown, with a large blackish central spot and two small round blackish spots at its sides, sometimes connected with central spot. Prosternum yellowish to light brown, hypomeron slightly darkened. Elytra with elongate blackish spot posterior to humeri, elytral base and suture darkened, elytral epipleura uniformly pale. Ventral surface of mesothorax blackish. Metepisternum brown. Metaventrite blackish, darker at medial elevation. Abdomen yellowish to reddish-brown. Legs yellowish to light brown. Head. Clypeus with moderately dense and shallow punctation consisting of small transverse punctures; interstices without microsculpture. Anterior margin of clypeus with narrow bead. Frontoclypeal suture conspicuous as a zone without punctuation, vanished mesally. Frons with punctation similar to that on clypeus, punctures sparser on sides; interstices without microsculpture. Eyes rather small, interocular distance about 6 xthe width of one eye in dorsal view. Labrum membranous, nearly completely concealed under clypeus, only with narrowly exposed sinuate anterior margin. Mentum (Fig. 12a) subtrapezoid, widest at posterior fourth, about 2 xwider than long, 1.5 xwider at widest part than at anterior margin, strongly concave in anterior half, anterior margin not emarginate; surface almost glabrous, punctures small, shallow and sparse, almost vanishing anteromesally, interstices without microsculpture. Antenna with 9 antennomeres, scapus ca. 1.8 xas long antennomeres 2-6 combined; antennal club moderately elongate, about twice as long as wide, as long as scapus; antennomere 9 acuminate at apex. Prothorax. Pronotum transverse, widest at base 2.1 -2.2xwider than long; 1.7 -1.8xwider at base than between front angles, 1.8 xwider than head including eyes, as convex as pronotum in lateral view. Punctation rather dense and moderately deep, consisting of crescent-shaped punctures intermixed with denser, slightly smaller and rather transverse punctures; punctures slightly feebler on sides. Prosternum (Fig. 12b) strongly tectiform medially, median ridge (Fig. 12c) with the same width throughout, anterior apex not projecting ventrally. Antennal grooves distinct, with lateral margin curved. Pterothorax. Scutellar shield 1.2 xas long as wide, sparsely punctured. Elytra widest at anterior fifth, 1.0 -1.1xlonger than wide, 2.6 -2.8xas long as pronotum, 1.2 -1.3xas wide as pronotum, surface glabrous, with 10 series of punctures; series 6, 8 and 9 not reaching anterior margin, surface glabrous (Fig. 12d), serial punctures getting slightly smaller lateraly; intervals moderately convex; punctation on interval 1 and odd intervals composed of crescent-shaped setiferous punctures, close to striae denser and intermixed with smaller, transverse non-setiferous punctures; even intervals with non-setiferous punctures only; all interstices without microsculpture. Humeral bulge indistinct. Mesoventral plate (Fig. 12f) narrowly elongate, ca. 5.8 xas long as wide, widest at midlength, symmetrically narrowing to both apices, anterior apex pointed, posterior apex rounded, posterior tip slightly overlapping over anterior portion of metaventrite; surface with few sparse punctures. Metaventrite (Fig. 12g) with raised pentagonal area ca. as wide as long, weakly, sparsely, uniformly punctated, without visible setae, bare part not reaching anterior margin of metaventrite; femoral lines absent; lateral parts of metaventrite densely covered by short pubescence. Legs. Femora with sparse shallow punctures ventrally, interstices with weak microsculpture consisting of longitudinal lines; tibial grooves distinct. Tibiae with rather small lateral spines. Metatibiae moderately broad and long, straight, 0.33 xas long as elytra, 5 xas long as wide. Metatarsus long, 0.86 -0.89xas long as metatibia, with just a few short rather stout setae ventrally. Abdomen with five ventrites, first abdominal ventrite (Fig. 12h) about as long as the second and third ventrites together, with distinct median longitudinal carina narrowing posteriad, not projecting posteriorly in both sexes; fifth ventrite with acuminate apex and weakly bulged in both sexes (Fig. 12i). Male genitalia. Median projection of sternite 9 (Fig. 4i) rounded apically, with a pair of subapical setae, base symmetrical. Phallobase (Fig. 4f) almost 1.4 xlonger than parameres, narrow, parallel sided, base widely rounded, manubrium indistinct. Parameres nearly of the same width in basal 3/4, divergent near apex, rounded and weakly narrowing apically. Median lobe (Fig. 4g) narrow and subparallel throughout, pointed at apex (Fig. 4h), gonopore moderately large, basal portion of median lobe with dorsal plate narrow and simply bifid basally.   Variability. The general dorsal coloration of the pronotum and elytra varies from yellow to dark reddish-brown. In dark specimens, lateral pronotal spots join the large central spot, and the whole anterior part of elytra and the elytral suture are distinctly darkened, with pale areas maintained in humeral area and at sides of scutellar shield. In pale specimens, the lateral pronotal spots are rather small and sometimes very vague and indistinct, and the elytra are completely yellow except base, sutural interval and the posthumeral dark spots.  Distribution.  Cercyon insularisseems to be widely distributed across Greater and Lesser Antilles, here we are recording it from Cuba, Dominican Republic, Puerto Rico, Grenada, Saint Lucia and Dominica. It seems that all records of C. variegatusfrom the Caribbean (Jamaica, Puerto Rico: Smetana 1978; Dominica: Peck 2006) actually concern C. insularis, as we failed to find the true C. variegatusin the material examined. For that reason we consider C. insularisto occur in Jamaica, although we did not examine any specimens from Jamaica ourselves.  Bionomics. Most of the specimens were collected in cow and horse dung on pastures, in coffee plantations and in tropical forests; few were collected using flight intercept traps.  Discussion.  Chevrolat (1863)described C. insularisbased on a single specimen from Cuba collected by D. F. Poeyand deposited in Chevrolat's collection. On our request to loan this specimen, we received a single specimen standing under the name C. insularisin the Chevrolat collection, corresponding well with the original description and marked as a type. In contrast to the data mentioned by Chevrolat (1863), the specimen also bears a label indicating Habana as the place of its origin. Since there is no reason to doubt the type identity of this specimen, we correct the type locality of C. insularisto Habana, in agreement with the label data of the holotype.  Cercyon insulariswas only briefly mentioned once by Gundlach (1891)and its type was not reexamined, therefore its identity remained unclear. Our inspection of the type revealed it corresponds by coloration with what was recorded from the Caribbean as Cercyon variegatusSharp, 1882, by Smetana (1978), Hansen (1999)and Peck (2006). In order to determine the identity of the species present in the Caribbean we studied the lectotype of C. variegatus(Fig. 4 j-o, deposited in BMNH) and compared it to the type of C. insularisand additional recently collected material from Cuba. Based on this comparison, it became clear that Cuban specimens are not conspecific with C. variegatus, but belong to a different species indistinguishable from it by external morphology: all dissected Cuban specimens were conspecific, differed from C. variegatusby genital morphology, and no other species of the same external coloration was found. We hence consider the Cuban specimens conspecific with the type specimen of C. insularis, even though it cannot be dissected because of its poor condition. Both median lobe (Fig. 4g) as well as phallobase and parameres (Fig. 4f) are narrower in C. insularisthan in C. variegatus. The apices of parameres are rounded in C. insularis, while they are more acuminate in C. variegatus(Fig. 4l). Moreover, the apex of the median lobe of C. variegatushas a small flank on each side (Fig. 4n) (Full set of pictures of the lectotype of C. variegatusin www.flickr.com/photos/142655814@N07/albums/72157676248390724).   Cercyoninsularisand C. variegatusbelong to a species complex corresponding to the C. variegatusgroup of Smetana (1978), distributed from the southern USA to Argentina; the species within this complex can be only distinguished by the morphology of the male genitalia (Arriaga-Varela and Fikacek, pers. observation). Only two species of this species complex have been formally described ( C. variegatusand C. insularis) and the group requires a detailed revision. The species recorded from Suriname as " Cercyon rishwani" by Makhan (2004)also belongs to this species complex based on color pattern of the pronotum and the general shape of the aedeagus, but a more detailed comparison with C. insularisand C. variegatusis impossible based on the description and illustrations provided. " Cercyon rishwaniMakhan, 2004" is moreover considered a nomen nudum (see Short and Hebauer, 2006 for details).  Figure 8. Cercyon gimmelisp. n. a mentum b prosternum c lateral view of median ridge of prosternum d detail of elytral surface f mesoventral plate g metaventrite h median ridge of first abdominal ventrite i fifth abdominal ventrite.  Figure 9. Cercyonspp. n. a-d Cercyon armatipenissp. n. f-i Cercyon tainosp. n. a, f mentum b detail of pronotal surface c, h ventral view of pterothorax d, i detail of elytral surface g lateral view of median ridge of prosternum.  Figure 10. Cercyon sklodowskaesp. n. a mentum b detail of pronotal surface c lateral view of median ridge of prosternum d detail of elytral surface f mesoventral plate g metaventrite h median ridge of first abdominal ventrite i female fifth abdominal ventrite.  Figure 11. Cercyon spiniventrissp. n. a mentum b prosternum c lateral view of median ridge of prosternum d detail of elytral surface f mesoventral plate g metaventrite h median ridge of female first abdominal ventrite i fifth abdominal ventrite.  Figure 12. Cercyon insularisChevrolat a mentum b prosternum c lateral view of median ridge of prosternum d detail of elytral surface f mesoventral plate g metaventrite h median ridge of female first abdominal ventrite i fifth abdominal ventrite.  Figure 13. Cercyonspp. a-b Cercyon praetextatusSay c-d Cercyon nigricepsMarsham e-f Cercyon quisquiliusLinnaeus a, c, e mesoventral plate b, d, f metaventrite.