Gyrinus (Oreogyrinus) vinolentus, Gustafson & Short, 2017

Gustafson, Grey T. & Short, Andrew E. Z., 2017, Review of the whirligig beetle genus Gyrinus of Venezuela (Coleoptera: Gyrinidae), Acta Entomologica Musei Nationalis Pragae 57 (2), pp. 479-520 : 509-512

Gyrinus (Oreogyrinus) vinolentus sp. nov.

( Figs 35–36 , 40 , 42 , 45–46 , 49 , 59 –61, 75)

Type material. HOLOTYPE: J, ‘ VENEZUELA: Lara State / 9°46.707›N, 70°02.113›W, 1877 m / EHumocaro Bajo; nr. / Cascado del Vino , river margins & / pools, 12.vii.2009; leg. Short, Gustafson, Garcia, Inciarte, Camacho; VZ09-0712-03 A [white label, typed black ink]’ ‘ SEMC0879582 / KUNHM-ENT [white label with barcode, typed black ink]’ ( MIZA) . PARATYPES (46 spec.): same as holotypeexcept: SEMC 0879486– SEMC 087488, SEMC 0879490– SEMC 0879491, SEMC 0879498, SEMC 0879502– SEMC 0879503, SEMC 0879505, SEMC 0879506, SEMC 0879508, SEMC 0879510, SEMC 0879512, SEMC 0879514, SEMC 0879523– SEMC 0879528, SEMC 0879531, SEMC 0879536, SEMC 0879538, SEMC 0879539, SEMC 0879540, SEMC 0879544, SEMC 0879546– SEMC 0879548, SEMC 0879550, SEMC 0879556– SEMC 0879559, SEMC 0879561– SEMC 0879564, SEMC 0879569– SEMC 0879570, SEMC 0879577– SEMC 0879581, SEMC 0879585 ( MALUZ, MIZA, SEMC).

Diagnosis. Body form ( Fig. 36 ) broadly oval, in lateral view convex; pronotal disc with transverse crease strongly impressed, laterally with dense wrinkles ( Fig. 40 ); elytral disc of female with intervals I–III non-reticulate in basal half ( Fig. 45 ), IV–V reticulate at least in basal half, VI–X strongly reticulate ( Fig. 46 ), XI non-reticulate; female elytral striae V–IX sulcate; elytral lateral margin strongly interrupted before apex ( Fig. 42 ); metanepisternal ostiole present; aedeagus ( Fig. 49 ) with median lobe mostly parallel sided in basal 2/3, strongly constricted in apical 1/3, apex narrowly rounded; parameres rounded apically; gonocoxae ( Fig. 59 ) curved, with truncate apices.

Description. Size. Female length = 5.0– 5.5 mm, width = 3.0– 3.5 mm, male length = 4.0–5.0 mm, width = 2.5–3.0 mm. Habitus. Body form broadly oval, weakly attenuated anteriorly and posteriorly, widest point near mid-length; in lateral view dorsoventrally convex, greatest convexity near elytral mid-length, evenly depressed anteriorly and posteriorly.

Coloration ( Figs 35–37 ). Dorsally, head, pronotum, elytra black, with blue reflections; laterally reflections bronzy yellow and green, especially in females whose elytral lateral reticulation strongly bronzy green. Venter overall darkly colored; mouthparts, ventral surface of antennal pedicel, hypomeron, elytral epipleuron, mesoventrite medially, mesocoxae, and ultimate abdominal ventrite lighter in color – reddish brown to darker orange yellow; legs yellow in color; remainder of venter dark brown to black.

Sculpture and structure. Pronotum ofboth sexes with broad riffled lateralmargins ( Fig. 40 ); pronotal disc strongly wrinkled laterally ( Fig. 40 ), wrinkles associated with pronotal crease laterally, transversely impressed line anteriorly, and posterior margin of pronotum, wrinkles weakly present medially on posterior 1 /2 of pronotal disc. Female elytra ( Figs 35 and 42 ) with striae I–IV non-sulcate, striae V–VI sulcate only medially; VII–VIII strongly sulcate in basal 2/3 of elytron, stria Xmostly non-sulcate, only weakly sulcate in humeral region; stria XI strictly marginal. Female elytral disc with intervals I–III normally non-reticulate ( Fig. 45 ), always basally free of reticulation; interval IV–V always with reticulation present at least basomedially ( Fig. 45 ); intervals VI–X completely reticulate ( Fig. 46 ), reticulation with strongly impressed dense meshes, composed of scale-like sculpticells; interval XI free of reticulation. Male elytra ( Fig. 36 ) with striae I–IV non-sulcate; V–VII weakly sulcate after humeral region for brief extant; VIII–IX sulcate in humeral region, ending before apical 1/3 of elytron; stria X non-sulcate; stria XI strictly marginal. Male elytral disc with intervals I–XI without reticulation. Elytra of both sexes with lateral margins interrupted in apical 1/5 by strong swelling; elytral apex truncate to weakly rounded. Metanepisternal ostiole very small. Male genitalia ( Fig. 49 ). Aedeagus with median lobe narrow, shorter than parameres, basal 2/3 mostly parallel sided, very weakly attenuated, distinctly constricted at apical 1/3, apex narrowly rounded; in lateral view median lobe narrow, sinuate, weakly dorsally curved; parameres with apex weakly rounded, not truncate. Female genitalia ( Fig. 59 ). Gonocoxae curved, apices truncate, left gonocoxa more strongly curved than right.

Variability. There is variability in the extant and appearance of the reticulate region of the female elytral disc. Normally females have reticulation present on interval IV in the basal half of the elytra, however, some specimens had thereticulation relatively weakly impressed. Others had it as strongly impress as the other more lateral elytral intervals. Some specimens had faint reticulation extending as far medially as the basal half of interval III.

Differential diagnosis. Gyrinus vinolentus is most similar to G. venezolensis but can be distinguished from it by the characters provided in the diagnosis for G. venezolensis .

Etymology. The type locality is near Cascada del Vino, an area where the water is tinted dark red, like wine, due to plant tanins. The specific epithet, Latin adjective vinolentus , means full of wine, or drunk, in reference to the wine-like waters of the type locality (Fig. 60).

Habitat. The only known collecting event for this species is from the margins of pools in a swift flowing mountain stream (Figs 60–61).

Distribution. Only known from thetype locality in thenorthern Venezuelan Andes ( Fig. 75 ).

Species inquirendum

Figures

Figs 33–38.Dorsal habitus of Oreogyrinus species, scale bar = 1 mm. 33 – Gyrinus venezolensis Ochs, 1953, female. 34 – G. venezolensis, male. 35 – G. vinolentus sp. nov. female. 36 – G. vinolentus, male. 37 – G. iridinus sp. nov., female paratype. 38 – G. iridinus, male holotype.

Figs 39–40. SEM images of the pronotum showing sculpturing of wrinkles and riffles of the lateral margins, arrows indicate pronotal transverse crease. 39 – Gyrinus venezolensis Ochs, 1953. 40 – G. vinolentus sp. nov.

Figs 41–42. SEM images of the elytron of Oreogyrinus species, scale bars = 1mm, arrows indicate the pre-apical swelling interrupting the elytral lateral margin. 41 – Gyrinus venezolensis Ochs, 1953. 42 – G. vinolentus sp. nov.

Figs 43–46. SEM images of elytral interval reticulation and strial punctures. 43–44 – Gyrinus venezolensis Ochs, 1953. 43 – intervals II and III, striae I–III. 44 – intervals IX and X, striae VIII–X. 45–46 – G. vinolentus sp. nov. 45 – intervals II and III, striae I–III. 46 – intervals IX and X, striae VIII–X.

Figs 47–50. Dorsal and lateral view of the aedeagus of Oreogyrinus species, not to scale. 47 – Gyrinus colombicus Régimbart, 1883, syntype (MNHN). 48 – G. venezolensis Ochs, 1953. 49 – G. vinolentus sp. nov. 50 – G. iridinus sp. nov.

Figs 51–59. Ventral view of gonocoxae of Venezuelan Gyrinus species, not to scale. 51–56 – Neogyrinus species. 51 – G. gibbus Aubé, 1838 from Caracas valley, Venezuela (FMNH). 52 – G. gibbus from Amazonian Venezuela: Amazonas stream along Rio Sipapo (KBMC). 53 – G. ovatus Aubé, 1838 from Venezuela: Falcón: W. Curimagua, Blackwater Lagoon.54 – G. guianus Ochs, 1935 from Amazonian Venezuela:Amazonas:river near Orinoco /Sipapo confluence (KBMC). 55 – G. rozei Ochs, 1953. 56 – G. sabanensis sp. nov. 57–59 – Oreogyrinus species: 57 – G. iridinus sp. nov. 58 – G. venezolensis Ochs, 1953. 59 – G. vinolentus sp. nov.

Figs 72–75. Distribution maps of Gyrinus species within Venezuela.