Oocyclus floccus Short & García, 2010

Short, Andrew E. Z. & García, Mauricio, 2010, A review of the Oocyclus Sharp of Venezuela with description of twelve new species (Coleoptera: Hydrophilidae: Laccobiini), Zootaxa 2635, pp. 1-31 : 12-13

Oocyclus floccus Short & García sp. n.

( Fig. 4 C, 5D, 7)

Type material. Holotype: VENEZUELA: Bolívar State: male, “ VENEZUELA: Bolívar State/ 5°43'30.9"N, 61°36'35.8"W, 1385 m / Rio Toron; side road, 12 km N of/ rd. to Kavanayen; AS-08-064/ leg. A. Short, M. García, L. Joly”, “[barcode]/ SM0828650/ KUNHM-ENT”, “Collection Date:/ 1.viii.2008 ”, “ HOLOTYPE / OOCYCLUS / floccus sp.n. / des. Short & García 2010 ” ( MIZA). Paratypes (100 exs.): VENEZUELA: Bolívar State: same data as holotype (74 exs.); Along La Escalera, Highway 10, 6°2'10.5"N, 61°23'57.8"W, 630 m, rock stream, 31.vii.2008, leg. A. Short, M. García, & L. Joly, AS-08-058 (26 exs.).

Diagnosis. Small to medium species ( Fig. 4 C). Posterolateral corners of pronotum rounded. Procoxae weakly spinose. Elytra with distinct rows of systematic punctures, which bear clumps of erect (occasionally decumbent) setae. Elytral suture not raised at apex. Elytral margins not explanate, and fringed with long yellow setae. Most similar to O. bolivari ; see diagnosis of that species.

Description. Size and form. Body length = 3.6–4.5 mm. TL/GW = 1.5. Body oval, moderately convex.

Color. Dorsum of head, pronotum, and elytra black with general faint iridescent green sheen. Anterolateral margins of pronotum with broad pale patch. Elytra with faint bronze to green maculae on discal region. Maxillary and labial palps yellow. Mentum and stipes light to reddish brown, distinctly paler than ventral face of head. Legs, epipleura, lateral margins of prosternum yellowish brown. Abdominal ventrites dark brown.

Head. Ground punctation on labrum, clypeus and frons fine, distance between punctures 1.5–3.0× the width of one puncture. Systematic punctures on labrum consisting of several indistinct punctures medially. Frons with irregular row of systematic punctures mesad of each eye. Clypeus with a few very indistinct systematic punctures along anterolateral margins, slightly larger than surrounding punctation. Maxillary palps short, shorter than width of labrum; segment 2 slightly bulbous, apical segment slightly longer than penultimate. Labial palps three-fourths as long as width of mentum. Mentum quadrate, anterior margin slightly convex, bearing very fine punctures.

Thorax. Ground punctation on pronotum and elytra composed of moderately impressed, evenly distributed punctures of generally uniform size. Pronotal systematic punctures set with short fine setae, similar to slightly larger in size to ground punctures; blending with larger ground punctures. Lateral margins of pronotum and elytra with dense row of yellow setae, creating fringed appearance. Posterolateral corners of pronotum rounded. Sutural punctation on elytra absent or unmodified from ground punctation. Elytra with five distinct rows of clumps of systematic punctures, each clump composed of several coalesced punctures which each bears short erect yellow seta. Prosternum with sharp, high carina elevated anteromedially, the elevation bearing two short coarse spine-like setae. Elevated process of mesoventrite raised to a point medially, with flat, even posteriorly sloping face set with 4–5 thickened spine-like setae. Metaventrite with oval glabrous area posteromedially, about twice long as wide, length of glabrous area ca. half the length of metaventrite. Procoxae with dense, fine short pubescence; with a few short thickened setae or spine-like setae mesally, which are easily overlooked. Protibiae each with 6–7 spine-like setae on dorsal face.

Abdomen. Ventrites with scattered setae of varying lengths; each ventrite with irregular rows of long erect setae which are distinctly longer than the longest setae on the metaventrite. Aedeagus as in Figure 5 D.

Variation. Specimens from the two known localities (the Escalera and Rio Toron sites) differ slightly in that the Rio Toron specimens are slightly larger on average, and have more compact, erect tufts of setae while specimens from the Escalera site have often some decumbent setal clumps on the elytral disc. Most Rio Toron specimens lack iridescent maculae and thus appear more dull than the Escalera specimens, which mostly have iridescent maculae, but there are exceptions in both cases. The genitalia, however, are similar and we attribute these differences to geographic variation.

Etymology. Floccus , Latin, tuft of hair, referring to the clumps of golden setae on the elytra.

Distribution. Southeastern Venezuela (Bolívar State) ( Fig. 7 ).

Remarks. This species is known from two geographically close, but ecologically different localities: one collection was made on flat wet rock in a densely forested stream at about 600 meters elevation, while the other was made on a seepage/wet rock region in mostly-open riparian corridor at nearly 1400 meters.

Figures

FIGURE 4. Dorsal and lateral habitus of Oocyclus species found in the Venezuelan Guiana Shield region. A) O. petra sp. n., B) O. coromoto sp. n.; C) O. floccus sp. n. Scale bar = 2.0 mm.

FIGURE 5. Aedeagi of Oocyclus species. A) O. pittieri sp. n., B) O. maculatus Sharp; C) O. s ubstillus Short & Perkins; D) O. floccus sp. n.; E) O. trujillo sp. n.; F) O. andinus sp. n.; G) O. meridensis sp. n.; H) O. sapphirus sp. n. Scale bar = 0.2 mm.

FIGURE 7. Distribution of Oocyclus species in Venezuela.