Cercyon spiniventris, Arriaga-Varela, Emmanuel, Seidel, Matthias, Deler-Hernandez, Albert, Viktor Senderov, & Fikacek, Martin, 2017

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 : 53-55

Cercyon spiniventris sp. n. Figures 3 a–c, 6 e–h, 11 a–i, 16a

DNA barcode.

GANTC010-17

BIN ID.

BOLD:ADF5572

Figures in Flickr: www.flickr.com/photos/142655814@N07/albums/72157671689463811

Type locality.

Dominican Republic, Monseñor Nouel Province, Parque Nacional La Humeadora; 11.6 km SSW of Piedra Blanca, 636 m a.s.l., 18°44.92'N, 70°21.63'W.

Type material.

Holotype (male): "DOMINICAN REP.: Msñ. Nouel, PN La Humeadora; 11.6km SSW, of Piedra Blanca; 18°44.92'N, 70°21.63'W; 636 m; 8.ix.2014, Deler, Fikáček, Gimmel DR41 // in horse excrement in moist broad-leaf forest in a valley of a small stony stream" (NMPC) [DNA extract: MF1216.1]. Paratypes: DOMINICAN REPUBLIC: Barahona: "DOMINICAN REP.: Prov. Barahona. nr. Filipinas, Larimar Mine: 26-VI/7-VII-1992: Woodruff, Skelley, Skillman. dung trap (1 males: FSCA). "DOMINICAN REP.: Prov. Barahona. nr. Filipinas, Larimar Mine: 26-VI/7-VII-1992: Woodruff & Skelley, rat carrion" (2 females: FSCA). Monseñor Nouel: same data as the holotype (7 males, 3 females, 12 spec.: NMPC; 2 males: BCPC; 2 males: BMNH; 2 males: CNC; 3 males: CNIN; 3 males: NHMW; 4 males, 1 female: SBNM; 3 males: SBP; 2 ZMUC). Duarte: "DOMINICAN REP.: Duarte. 9.1 km SW of El Factor, slope above La Factoria; 19°15.30'N, 69°56.52'W; 255 m; 4.ix.2014. Deler, Fikáček, Gimmel DR32 // area with cocoa plantations and small remnants of forests at very steep slopes: in horse excrement" (2 males: NMPC). Independencia: "DOMINICAN R.: Independencia, PN Sierra de Neiba, 11.3 km NW of La Descubierta; 1650 m, 18°39.81'N, 71°46.17'W; 18.viii.2014, Deler,Gimmel DR13 // disturbed montane cloud forest with many ferns and mosses: in cow excrement" (2 males, 4 females, 1 spec.: NMPC). La Vega: "DOMINICAN REP.: La Vega, PN A. Bermúdez, 8 km W of Manabao, 19°4.05'N, 70°51.98'W, 1140 m, 22-26.viii.2014, Deler, Fikáček, Gimmel DR16 // montane broad-leaf forest: in cow and horse excrement" (12 males, 15 females: NMPC; 1 male: BMNH; 1 male: CNIN; 2 males: FSCA; 1 male: MNHNSD; 3 males, 2 females: SBNM) [DNA extraction of one male: MF1753 in NMPC]; "DOM. REP; La Vega Prov., 10km NE Jarabacoa, Hotel Montana, forest, 18.VII-4.VIII.95, 550m, FIT, S.+J. Peck, 95-30" (2 females: CMN); "DOM. REP; La Vega Prov., PN. A. Bermudez, Cienaga, 19.VII-2.VIII.95, 1000m, trop.evgrn.for., FIT, S.+J. Peck, 95-32" (2 females: CMN); "DOM. REP; La Vega Prov., PN. A. Bermudez, Cienaga, 19.VII-2.VIII.95, 1020m, trop.evgrn.for., FIT, S.+J. Peck, 95-34" (1 male: CMN); "DOM. REP; La Vega Prov., PN. A. Bermudez, Cienaga, 21.-24.VII.95, 1000m, for. carrion trap, S.+J. Peck, 95-38" (1 female: CMN). Samaná: "DOMINICAN REP.: Samaná, MN Salto El Limón 2.8 km SSW of El Limón; 19°16.56'S 69°26.47'W; 160 m; 2.ix.2014, Deler, Fikáček, Gimmel. DR29a // secondary vegetation and tiny remnants of forest among coffee plantations and pastures: in horse excrement" (3 males, 3 females: NMPC).

Diagnosis.

Body size 3.4-4.1 mm; dorsal surface of head black with yellowish anterolateral margins of clypeus (Fig. 3a); pronotum homogeneously light brown, elytra greyish-brown; medial ridge of prosternum anteriorly with a small rounded process (Fig. 11c); mesoventral plate narrow, ca. 5.9 × as long as wide; metaventrite (Fig. 11f) without femoral lines; raised pentagonal area of metaventrite moderately wide, 0.9 × as long as wide; first abdominal ventrite with an spiniform process in females (Fig. 11h), without process in males; apex of fifth abdominal ventrite without apical triangular projection in both sexes (Fig. 11i); aedeagus with parameres about as long as phallobase (Fig. 6e), median lobe narrowly parallel-sided, acute at apex, without spines.

Cercyon spiniventris somewhat resembles C. nigriceps by the dorsal coloration pattern (predominantly black head and rather homogeneously brown pronotum and elytra); it can be easily distinguished from C. nigriceps by much larger body size (3.4-4.1 mm in C. spiniventris , 1.0-2.1 mm in C. nigriceps ) and by the lack of femoral lines on the metaventrite (present in C. nigriceps ). Cercyon spiniventris is unique among Caribbean Cercyon species by a presence of a long spiniform process in the first abdominal ventrite of females.

Description.

Body (Fig. 3 a–c). 3.4-4.0 mm long (length of holotype: 3.5 mm); moderately short-oval, 1.8 –1.9× as long as wide, widest at basal fourth of elytra; moderately convex, 2.9 –3.0× as long as high (height of holotype: 1.15 mm). Coloration. Dorsal surface of head blackish to pitchy black, clypeus with wide rather sharply defined yellowish area along anterolateral margins, broader at sides. Antennae and ventral surface of head black, mentum with posterior half yellowish brown, mouthparts and antenna yellowish brown, antennal club dark-brown. Pronotum light brown. Prosternum yellowish-brown with posterior half black, hypomeron brown with large black marks on posterior third, and close to the yellowish-brown lateral margins. Elytra dark greyish-brown, with lateral and anterior margins, apex and epipleura slightly paler. Ventral surface of mesothorax blackish to pitch-black, with procoxal rests and mesoventral plate brown. Metepisternum black. Metaventrite black with paler raised anteromedial part. Abdomen black, posteromedial margins and anterolateral corners of ventrites brownish. Legs brown, femora dorsally black.

Head. Clypeus with dense and moderately deep punctation consisting of crescent-shaped setiferous punctures intermixed with denser, smaller and rather transverse non-setiferous punctures; interstices without microsculpture. Anterior margin of clypeus with a narrow bead. Frontoclypeal suture conspicuous as a zone without punctuation, vanished mesally. Frons with punctation similar to that on clypeus, punctures of same shape all over; interstices without microsculpture. Eyes rather small; interocular distance about 5.4 × the width of one eye in dorsal view. Labrum membranous, nearly completely concealed under clypeus, only with narrowly exposed sinuate anterior margin. Mentum (Fig. 11a) subtrapezoid, widest at posterior fourth, about 2 × wider than long, 1.5 × wider at widest part than at anterior margin, weakly concave in anterior half; surface glabrous, punctures large and deep, becoming coarser anteromesally, interstices on anterior half with transverse depressions near each puncture. Antenna with 9 antennomeres, scapus ca. 1.8 × as long as antennomeres 2-6 combined; antennal club moderately elongate, about twice as long as wide, about as 1.2 × as long as scapus; antennomere 9 acuminate at apex.

Prothorax. Pronotum transverse, widest at base 2.1 –2.3× wider than long; 1.7 × wider at base than between anterior angles, 1.8 × wider than head including eyes, as convex as elytra in lateral view. Punctation rather dense and moderately deep, consisting of crescent-shaped setiferous punctures intermixed with denser, smaller and rather transverse non-setiferous punctures; punctures slightly feebler on sides. Prosternum (Fig. 11 b–c) strongly tectiform medially, medial ridge very weakly thickened ante riad, forming a small rounded process. Antennal grooves distinct, with lateral margin curved, feebler anteriad.

Pterothorax. Scutellar shield about as long as wide, moderately densely punctured. Elytra widest at anterior fifth, 2.7 –2.9× as long as pronotum, 1.1 –1.2× as wide as pronotum, surface (Fig. 10d) glabrous, with 10 series of punctures; series 6, 8 and 9 not reaching elytral base, serial punctures of same size in all series; intervals moderately convex; interval punctation composed of crescent-shaped setiferous punctures intermixed with denser, smaller and rather tranverse non-setiferous punctures; setiferous punctures present on all intervals; interstices without microsculpture. Humeral bulge indistinct. Mesoventral plate (Fig. 11f) narrowly elongate, ca. 5.9 × as long as wide, widest at midlength, gradually and symmetrically narrowing to pointed apices, posterior tip slightly overlapping over anterior part of metaventrite; surface with coarse punctures. Metaventrite (Fig. 11g) without femoral lines, raised pentagonal area wide, 0.8 × as long as wide at widest portion, glabrous, rather weakly and sparsely punctate, punctures with fine setae at least along margins of elevation, punctures absent at two slightly elongate areas in the center, bare area not reaching anterior margin of metaventrite mesally; lateral parts of metaventrite densely covered by short pubescence.

Legs. Femora with sparse rather shallow punctures ventrally, interstices with weak granulose microsculpture; tibial grooves distinct. Tibiae with moderately large lateral spines. Metatibiae moderately narrow and elongate, slightly bent outwards, 0.4 × as long as elytra, 6.0 × as long as wide. Metatarsus moderately long, 0.7 –0.8× as long as metatibia, with short rather stout setae ventrally.

Abdomen with five ventrites, first abdominal ventrite longer than second and third ventrites combined, with long setae in medial third, median longitudinal carina present, slightly narrowing posteriad, not projecting posteriorly in males, projecting posteriad as a short spine in females (Fig. 11h); ventrite 5 with acuminate apex in both sexes.

Genitalia. Median projection of sternite 9 (Fig. 6h) rounded apically, without subapical setae, median portion narrowing posteriorly, shorter than lateral struts. Phallobase (Fig. 6e) about as long as parameres, asymmetrically narrowing basally, base acuminate and slightly hooked. Parameres weakly narrowing apically, subsinuate near apex, apex pointed apically. Median lobe (Fig. 6f) narrow, parallel-sided throughout, apex acuminate, gonopore moderately large, situated subapically; basal portion with dorsal horseshoe-shaped plate, base bifid. throughout, apex acuminate, gonopore moderately large, situated subapically; basal portion with dorsal horseshoe-shaped plate, base bifid.

Etymology.

The name of this species is derived from Latin words spina (spine) and venter (underside), in reference to the spine-like process on the first abdominal ventrite of females.

Distribution.

Dominican Republic: Duarte, Independencia, La Vega, Monseñor Nouel, Samaná (Fig. 16a).

Bionomics.

Most of the specimens were collected in cow and horse dung in tropical forest and surrounding pastures.