Oocyclus pilosus, Jordão & Clarkson & Ferreira-Jr, 2018

Jordão, Rafael, Clarkson, Bruno & Ferreira-Jr, Nelson, 2018, A new species and new records of Oocyclus Sharp, 1882 (Coleoptera: Hydrophilidae) from Brazil, Zootaxa 4382 (1), pp. 195-200 : 195-198

Oocyclus pilosus sp. nov. ( Fig 1 )

Type locality. Brazil, Mato Grosso State, Jaciara Municipality, Estrada Parque ( Park Road ), Tenente Amaral River , Mulata Waterfall. 15°58’50.4”S 55°02’55.6”W.

Type Material. Holotype male. “ Brasil, Mato Grosso, Jaciara, Estrada Parque, Rio Tenente Amaral, Cachoeira da Mulata. / 15°58’50.4”S 55°02’55.6”W. 23-VII-13. / B Clarkson, BHL Sampaio, N Ferreira-Jr., ALH Oliveira. legs” ( DZRJ 6625 ) . Paratypes (26): Brazil, Mato Grosso State, Jaciara Municipality, Parque Road, Tenente Amaral River, Mulata Waterfall. / 15°58’50.4”S 55°02’55.6”W. 23-VII-13. B Clarkson, BHL Sampaio, N Ferreira-Jr. ALH Oliveira. legs. / (14 exs., DZRJ 6626 ) ; // Power Plant Fumaça Waterfall. / 15°58’45”S 55°02’4.9”W. 23-VII-13. B Clarkson, BHL Sampaio, N Ferreira-Jr., ALH Oliveira. legs. / (2 exs., DZRJ 6620 ) ; // Chapada dos Guimarães Municipality, Chapada dos Guimarães National Park, Independência stream, Degraus Waterfall. / 15º24’58.7”S 55º50’33.7”W. 20-VII-13. B Clarkson, BHL Sampaio, N Ferreira-Jr, ALH Oliveira. legs. / (1 ex., DZRJ 6627 ) ; // Brazil, Mato Grosso State, Chapada dos Guimarães Municipality, Chapada dos Guimarães National Park, Independência stream Degraus Waterfall. / 15°24’58.5”S 55°50’34”W, 583m wall with moss. 06-III-2016. N. Ferreira-Jr., B.A.C. Guimarães legs. / (1 ex., DZRJ 6639 ) ; // Independência stream, Pulo Waterfall. / 15°24’59.7”S 55°50’29.3”W, 601m. Wet slab. 05-III-2016. N. Ferreira- Jr., B.A.C. Guimarães legs. / (1 ex., DZRJ 6649 ) ; // Independência stream Andorinha Waterfall , 15°27’29.1”S 55°44’47.4”W, rock wall. 05-III-2016. N. Ferreira-Jr., B.A.C. Guimarães. legs / (7 exs., DZRJ 6641 ) .

Differential Diagnosis. Oocyclus pilosus sp. nov. shows yellowish and erect setae around the margins of elytra and pronotum, a row of black dots along the elytral suture, yellowish-green sheen in elytra and nearly flat pronotal carina without spine-like setae. Oocyclus pilosus sp. nov. can be distinguished from the most similar Brazilian species, O. schubarti and O. yubai by its erect setae around the margins of elytra and pronotum, giving the latter a fringe-like appearance, and the absence of spine-like setae in the pronotal carina, which are found in all species currently known from Brazil.

Description. Size and form. Holotype: Body length = 4.0 mm. TL/GW= 1.02 mm.; Paratypes: TL =4.0 – 5.1 mm; TL/GW = 1.0- 1.2 mm.

Color. Dorsum of head, pronotum and elytra olive green, covered by a golden sheen ( Fig. 1 ). In elytra, the sheen resembles a stripe pattern. Anterolateral margins of pronotum with a pale patch about half the margin length. Four to six black dots along the elytral suture in each elytron paralleled or subparalleled. Both elytra show a narrow pale spot in distal quarter. Antennomers 1–8 and labial palps light brown; ventral face of head black. Lateral margins of prosternum and pseudoepipleura brown, epipleura light brown. Legs light brown. Abdominal ventrites dark orange

Head. Ground punctation on labrum, clypeus and frons with fine punctures of the same size, distance between punctures about 3.0x the width of one puncture. Few fine setae around the ocular suture. Maxillary palps subequal to the width of labrum, apical segment longer than penultimate. Labial palps nearly half as long as width of mentum, apical segment slightly longer than penultimate. Mentum smooth, subquadrate, anterior margin slightly convex.

Thorax. Pronotal and elytral systematic punctures ca. twice the size of the ground punctures with long fine setae distributed along the pronotal anterior margin. Anterolateral margins of pronotum with a paler patch approximately 0.5 mm in length and shows a fringe of long setae along the pronotal margin, posterolateral margins of pronotum weakly rounded. Elytra with five distinct rows of systematic punctures, each one bearing fine setae, row 1 along the elytral suture, rows two and three become fused and indistinct from distal quarter of elytra to posterior end, rows four and five irregular, blending with overall punctures. Prosternum carinate, tectiform, slightly elevate anteromedially, elevation without coarse-like spines ( Fig. 2A ). Elevated process of mesoventrite narrow and elongate, more than three times as long as wide; with an irregular surface, rather tectiform; set with 4–6 coarse spine-like setae. Metaventrite with oval glabrous area posteromedially, distinctly longer than wide, length of glabrous area nearly three-quarters length of metaventrite. Procoxae with fine short pubescence, without spines. Protibiae each with 10–12 spine-like setae on dorsal face. Meso and metafemora with scattered punctures without setae.

Abdomen. Ventrites 1–5 bearing long erect setae slightly aligned in three transversal rows, distinctly longer than the longest setae on metaventrite. Outer margin of paramera weakly sinuose, gradually tapering to the apex, bending inwards; inner margin straight, tapering from the posterior half; median lobe nearly the length of paramera, slightly short, without a hooked apex, gonopore located at medial half. Basal piece distinctly constricted ( Fig. 3).

Etymology. Pilosus, Latin adjective referring to the hairy aspect of erect setae in dorsal view and the long setae on the abdominal ventrites.

Distribution. Known only from the type locality ( Fig. 4 ).

Figures

FIGURE 1. Oocyclus pilosus sp.nov. habitus:A)Dorsal view,B) Ventral view,C) Lateral view.

FIGURE 2. Detailed comparison betweenprosternal carina of O. pilosussp. nov. (A) and O.yubai Clarkson &Short 2012 (B).

FIGURE 4. Map of geographicdistribution of the Oocyclus pilosus sp. nov. andnew records of Oocyclus spp.