Oocyclus bhutanicus Satô, 1979

Short, A. E. Z. & Swanson, A. P., 2005, A revision of the Oocyclus Sharp of Thailand with description of six new species (Coleoptera: Hydrophilidae), Zootaxa 1078, pp. 1-24 : 4-5

Oocyclus bhutanicus Satô, 1979

Oocyclus bhutanicus Satô, 1979: 53 .

Oocyclus bhutanicus: Hebauer & Wang, 1998: 43 (in part).

Type Material Examined. Holotype: Male. “km 87 von 30.4 / Phuntsholing”, “Nat.­ Hist. Museum / Basel­Bhutan / Expedition 1972”, “Hydro­ / philidae / det. Vogt 1976”, “Slide No. / Bhutan­24 / M. SATO, 1978”, “ Holotype / Oocyclus / bhutanicus / M. Sato/ DET. M. SATO 1977” ( NMB).

Additional Material Examined. NEPAL: Taplejung District, between Hellok and lower Gunsa khola, 1620–2000 m, 18.v.1988, J. Martens & W. Schawaller leg., det. by F. Hebauer (1: AEZS).

Diagnosis. Posterolateral corners of pronotum evenly rounded. Procoxae without distinct spines. Abdominal ventrites finely and evenly pubescent. Elytra without detectable rows of systematic punctures. Most similar to O. sitesi and O. viridescens but those species have only a few rows of sparse, long hairs on the abdominal ventrites.

Description. Size and Form. Length= 4.1 mm. EL/EW= 1.12 mm. Oval, moderately convex. Elytra longer than wide. Color. Dorsum black. Head and pronotum with very faint and indistinct greenish sheen. Maxillary and labial palpi yellow. Mentum and stipes light to reddish brown, distinctly paler than ventral face of head. Legs, epipleura, lateral margins of prosternum, and posterior margin of each ventrite yellow to light brown, with remainder of venter slightly to moderately darker reddish brown. Head. General punctation on labrum, clypeus and frons slightly variable in size from very fine to moderately fine; fairly densely distributed, distance between punctures 1.0–1.5x the width of one puncture. Systematic row of punctures on labrum moderately dense, forming a nearly continuous lateral row set with moderately long setae, but each puncture still fairly distinguishable, not forming a groove. Frons with an irregular row of systematic punctures mesad of each eye, bearing fine erect setae. Clypeus with a few very indistinct systematic punctures along anterolateral margins, slightly larger than surrounding punctation and bearing short setae. Antennae with scape subequal in length to segments 2–5; first two segments of club subequal in length and apical segment slightly longer than two preceding segments combined. Maxillary palpi short, about as long as width of labrum; segment 2 slightly bulbous, apical segment slightly longer than penultimate. Labial palpi three­fourths as long as width of mentum. Mentum quadrate, anterior margin slightly convex, bearing very fine and scattered punctures. Thorax. General punctation on pronotum and elytra composed of extremely fine and moderately coarse punctures, evenly mixed and distributed. Pronotal systematic punctures present, ca. 1.5–2.0x the size of general punctation and set with a fine seta, sometimes partially blending with larger general punctures; anterior and posterior series each forming an irregular row. Lateral margins of pronotum set with a few sparsely distributed setiferous punctures; with punctures almost appearing absent. Posterolateral corners of pronotum evenly rounded. Sutural punctation on elytra absent or unmodified from general punctation. Elytra without distinct rows of larger punctures, as they blend uniformly with general punctation; some of these rows (of systematic punctures) can be detected by the presence of fine, short setae (most of these setae seem to be worn off on the holotype). Prosternum with median carina along entire length, without distinct anteromedial tooth; without long spines or hairs anteriorly. Mesosternal process with lateral extensions sloping evenly downward; apex set with a few long fine setae. Metasternum with small oval glabrous area posteromedially, slightly longer than wide, length of glabrous area about half the total length of metasternum. Pro­ and mesocoxae densely pubescent; without distinct spines. Protibiae with 10 spines on dorsal face. Protarsal segments 1–4 small, subequal in length; apical segment ca. as long as segments 1–4 combined. Abdomen. Ventrites 1–5 with uniform pubescence, longest setae about as long as the setae around the metasternal glabrous area. Fifth ventrite entire. Aedeagus not examined (previously dissected and separated from specimen; exact location unknown).

Distribution. Bhutan ( Satô 1979), Nepal ( Hebauer & Wang 1998). All other records from Thailand and Taiwan ( Hebauer & Wang 1998) need confirmation.

Remarks. This species was originally described from a single male from Bhutan ( Satô 1979). The type has subsequently been on loan for nearly 25 years to USNM and was not examined by Hebauer and Wang (1998). In addition, the genitalia were slide mounted and separated from the holotype before it was sent to USNM. The location of the slide preparation is unknown.

After examining material previously identified by Hebauer, it became clear that O. bhutanicus sensu Hebauer and Wang (1998) was composite. One male specimen from Nepal labeled as O. bhutanicus by Hebauer agrees well with the holotype. However, a specimen from Taiwan identified as the same is a different, undescribed species. We have not seen material from Thailand examined by Hebauer and Wang, but it is very likely that those specimens actually refer to O. viridescens . No new (or old) Thailand representatives of the true O. bhutanicus were seen.