Oocyclus rupicola Minoshima

Minoshima, Yûsuke, 2009, First record of the hygropetric genus Oocyclus Sharp (Coleoptera: Hydrophilidae) from Laos, with description of a new species, Zootaxa 2192, pp. 45-55 : 46-51

publication ID	https://doi.org/ 10.5281/zenodo.189408
DOI	https://doi.org/10.5281/zenodo.6219756
persistent identifier	https://treatment.plazi.org/id/03CC87B8-4801-FF99-22D0-5049FB1CFF5F
treatment provided by	Plazi
scientific name	Oocyclus rupicola Minoshima
status	sp. nov.

Treatment

Oocyclus rupicola Minoshima View in CoL , sp. n.

( Figs. 1–3 View FIGURE 1 View FIGURE 2 View FIGURE 3 )

Type Locality. Laos: Bolikhamxai Province, 11km Southwest by West of Ban Pakha, Route 8, N18°11.83´, E104°36.19´, alt. 580 m.

Type material. Holotype: Male. “[ LAOS: MiYu-L-08-039] Route 8,” / “ 11km SWbW of Ban Pakha,” / “Bolikhamxai prov.” / “(hygropetric: wet rock);” / “alt. 580m; N18°11.83´, E104°36.19´;” / “ 25.V.2008; MINOSHIMA Yûsuke leg.” // “MiYu-D-0 0 140” / “MINOSHIMA Yûsuke” / “ SEHU, Japan ” // “ HOLOTYPE ” / “ Oocyclus rupicola ” / “Minoshima” / “det. MINOSHIMA Yûsuke” / “2009” // “0000007945” / “Sys.Ent.” / “Hokkaido Univ.” / “ Japan [ SEHU]” [“D-00140”, handwritten on a slide glass card]( SEHU). Paratypes: 8 males and 10 females, same locality as holotype ( EUMJ, KSEM, SEHU (7946– 7952), MYC).

Description. Male. Body broadly oval, moderately convex ( Fig. 1 View FIGURE 1 , 2 View FIGURE 2 A). Color. Dorsum black with greenish luster, slightly iridescent; but more vividly colored when wet condition. Ventral surface of head dark brown to black. Antennae, maxillary palpi, labial palpi rather light yellowish-brown; pubescent club of antennae brown; apex of maxillary palpomere 4 darkened. Mentum dark reddish-brown, anterior margin slightly paler; stipes reddish-brown, paler than ventral face of head. Lateral margins of prosternum, epipleura, and pseudepipleura reddish-brown, paler than median part of prosternum, mesoventrite, and metaventrite; epipleura slightly darker than pseudepipleura. Legs reddish brown; coxa and femora slightly darkened; tibia and tarsus paler. Abdominal ventrites dark reddish-brown to dark brown; posterior margins of ventrites slightly paler. Head. Labrum about 2.8 times as wide as long; punctation of labrum moderately fine, moderately densely distribution; systematic punctures of labrum composed of a row of coarse punctures bearing fine setae medially, dense mediolaterally, sparse medially. Clypeus with broadly and weakly rounded anterior margin; punctation of clypeus and frons composed of variously sized distinct punctures; interspaces between punctures about 0.5–1.0 times width of a puncture, sometimes more or less distance. Frontoclypeal suture fine, but distinct. Systematic punctures of frons bearing fine, short setae, present roundly along each eye. Antennal scape as long as the combined length of antennomeres 2–4; antennomere 3 short; antennomere 4 very short, about 0.5 times as long as antennomere 3; antennomere 5 moderately long, about the same length as antennomeres 6 and 7 combined; apical segment slightly longer than antennomere 7. Maxillary palpi short; palpomere 3 slightly shorter than palpomere 2; palpomere 4 about 1.3 times as long as palpomere 2. Labial palpi short, slightly shorter than width of mentum; palpomere 2 about as long as palpomere 3; palpomeres 2 and 3 with a few fine setae. Mentum flat, rectangular, anterior margin rounded, about 1.3 times as wide as long; punctation of mentum very fine, sparse; anterolateral margin of mentum with fine, distinct punctures bearing fine, short setae ( Fig. 2 View FIGURE 2 E). Thorax. Pronotal punctation moderately coarse, punctures of various sizes, finer and more densely distributed than those of clypeus and frons; interspaces between punctures about 0.5– 1.0 times width of a puncture; a few sparse setiferous punctures bearing fine, short erect seta present on lateral margin. Systematic punctures of pronotum bearing fine short recumbent setae; anterior series distinct, composed of an irregular row, longer than posterior row; posterior series slightly indistinct, more irregular than anterior one. Posterolateral corners of pronotum angulate ( Fig. 2 View FIGURE 2 C). Elytra longer than wide, subparallel on anterior half, broadly rounded apically; punctation of elytra moderately coarse, punctures of various sizes, more densely distributed than those of pronotum ( Fig. 2 View FIGURE 2 D); a few sparse setiferous punctures bearing fine, short erect seta present on outer margin; elytra with five rows of coarse, sparse setiferous punctures bearing recumbent to erect fine setae; punctures of rows slightly undetectable; row 5 with very sparsely distributed punctures. Prosternum with median carina along entire length, slightly projecting anteriorly, with fine setae on anterior margin ( Fig. 2 View FIGURE 2 F). Mesoventral process with a few fine setae on median carina; projecting ventrally, from lateral view slightly resembling bird's beak ( Fig. 2 View FIGURE 2 G). Metaventrite with rather oblong oval glabrous area posteromedially, about 2.8 times as long as wide, length of glabrous area about 0.6 times total length of metaventrite. Procoxae with moderately fine, densely distributed setae, with a few indistinct spines ( Fig. 2 View FIGURE 2 F); meso- and metacoxae with coarse setae. Profemur densely pubescent on about basal two-fifths, without distinct punctures; mesofemur with moderately coarse, irregularly and sparsely distributed punctures, interspaces between punctures about 1.0–4.0 times width of a puncture; punctation of metafemur finer, punctures sparser than those of mesofemur. Protarsal segments 1–4 small, subequal in length; apical segment about as long as combined length of segments 1–4. Abdomen. Abdominal ventrites with moderately dense pubescence. Aedeagus ( Figs. 3 View FIGURE 3 A, D): parameres about as long median lobe, swollen at base, subparallel on basal half of outer margin thence narrowing apically; punctation of parameres fine, moderately densely distributed; median lobe slender, slightly narrowed apically, weakly curved dorsally from lateral view ( Fig. 3 View FIGURE 3 D); punctation of median lobe very fine, punctures sparsely distributed; basal aphophysis moderately short; phallobase about 0.6 times as wide as long; punctation of phallobase fine, few sparsely distributed punctures present laterally; manubrium broadly rounded, indistinctly demarcated from phallobase.

Female. Body size slightly larger than male (see measurements); otherwise almost identical to male. Spermathecal organ ( Fig. 3 View FIGURE 3 E). Spermathecal duct long (278–296 (286 ± 7) μm; n = 5), distinctly longer than duct of the spermathecal gland, slender, slightly swollen at base; infundibulum undetectable; spermatheca rather small, slightly oblong oval; cornu undetectable; duct of the spermathecal gland short (58–72 (66 ± 5) μm; n = 5), swollen at medially, slender at base; spermathecal gland slender, slightly swollen.

Measurements. Male (n = 8): TL: 4.93–5.55 (5.22 ± 0.21) mm; HW: 1.45–1.60 (1.53 ± 0.06) mm; ED: 0.90–1.00 (0.94 ± 0.04) mm; PL: 1.18–1.28 (1.22 ± 0.04) mm; PW: 3.03–3.35 (3.18 ± 0.12) mm; EL: 3.75– 4.30 (4.01 ± 0.18) mm; EW: 3.40–3.75 (3.56 ± 0.14) mm; ED/HW: 0.59–0.63 (0.61 ± 0.01); PW/PL: 2.56– 2.68 (2.62 ± 0.04); EL/EW: 1.10–1.15 (1.13 ± 0.02). Female (n=10): TL: 5.28–5.85 (5.50 ± 0.19) mm; HW: 1.53–1.70 (1.62 ± 0.05) mm; ED: 0.95–1.08 (1.00 ± 0.04) mm; PL: 1.20–1.35 (1.28 ± 0.05) mm; PW: 3.10– 3.53 (3.31 ± 0.12) mm; EL: 4.05–4.50 (4.23 ± 0.16) mm; EW: 3.58–3.93 (3.75 ± 0.11) mm; ED/HW: 0.61– 0.65 (0.62 ± 0.01); PW/PL: 2.53–2.69 (2.59 ± 0.05); EL/EW: 1.09–1.19 (1.13 ± 0.03).

Distribution. Laos. Known only from the type locality.

Biology. Collected at the hygropetric habitat ( Fig. 6 View FIGURE 6. A ).

Etymology. The specific epithet is a combination of the Latin word “rupes”, meaning “rock”, and another Latin word “-cola”, meaning "inhabitant". The name was chosen in order to refer to the wet rock surface, which is the habitat of this new species.

Remarks. Judging from descriptions and figures of Short & Swanson (2005), this new species is most similar to O. sumatrensis d’Orchymont, 1932 ; it can, however, be distinguished from it by the following characters: 1) spines of procoxae thin, sparse and indistinct, resembling thickened, stiff setae ( Fig. 2 View FIGURE 2 F); 2) ground punctation of elytra very coarse ( Fig. 2 View FIGURE 2 D); 3) parameres narrowed apically ( Fig. 3 View FIGURE 3 A).