Oocyclus Sharp

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 : 3

Key to the Oocyclus Sharp of Thailand

1 Procoxae pubescent, without distinct spines. Posterolateral corners of pronotum evenly rounded ( Fig. 13 ). Abdominal ventrites evenly and finely pubescent or each with two rows of long hairs. Size usually less than 4.0 mm (except O. bhutanicus )... 2

­ Procoxae covered with short, coarse spines. Posterolateral corners of pronotum angulate or spinose ( Figs. 14, 15 ). Abdominal ventrites evenly covered with fine pubescence ( Fig. 8 ). Size usually larger than 4.0 mm (except some O. sumatrensis )........... 4

2 Abdominal ventrites with two or three irregular rows of long hairs............................. 3

­ Abdominal ventrites covered with fine, dense pubescence ( Fig. 8 )................................ ........................................................................................................ O. bhutanicus Satô

3 Elytra without distinct rows of systematic punctures; setiferous punctures present but almost indistinguishable from coarse general punctuation ........... O. viridescens sp. n.

­ Elytra with five distinct rows of setiferous punctures; general punctuation fine............ ................................................................................................................. O. sitesi sp. n.

4 Central metasternal glabrous area extending to the entire length of the metasternum ( Fig. 11 ). Abdominal ventrites uniformly pale, distinctly paler than sternum ( Fig. 8 ). Posterolateral corners of pronotum angulate but not spinose ( Fig. 14 ) .......................... ................................................................................................... O. melinoventris sp. n.

­ Central metasternal glabrous area not more than one­third the length of the metasternum (e.g., Fig. 10 ). Abdominal ventrites variously colored. Posterolateral corners of pronotum angulate or spinose ( Figs. 14, 15 )................................................................. 5

5 Posterolateral corners of pronotum slightly prolonged, spinose ( Fig. 15 ). Size usually larger (4.0– 5.1 mm)....................................................................................................... 6

­ Posterolateral corners of prontoum angulate ( Fig.14 ). Size usually smaller (3.7–4.3 mm) ...................................................................................... O. sumatrensis d’Orchymont

6 Abdominal ventrites uniformly pale (e.g., Fig. 8 ). General punctuation of elytra coarse ............................................................................................................... O. foxae sp. n.

­ Abdominal ventrites variously colored, but never uniformly pale. General punctuation of elytra not as coarse.................................................................................................... 7

7 Size 4.7–5.1 mm. Parameres only slightly tapered, more broadly rounded at tip ( Fig. 4 ). General punctuation of elytra slightly more coarse ................... O. thailensis sp. n.

­ Size 4.0– 4.5 mm. Parameres evenly tapered to a narrow, blunt tip ( Fig. 3 ). General punctuation of elytra more fine ........................................................... O. namtok sp. n.

Figures

FIGURE 8. Oocyclus melinoventris sp. n. (holotype). Ventral habitus. Scale bar = 2 mm.

FIGURE 10. Oocyclus sitesi sp. n. (holotype). Ventral habitus. Scale bar = 1 mm.

FIGURES 11 – 15. Details of Oocyclus. 11 – 12. Thoracic sterna. 11. O. melinoventris sp. n. (holotype). 12. O. sitesi sp. n. (holotype). 13 – 15. Lateral margin of pronotum, with posterolateral corner to the right. 13. O. viridescens sp. n. 14. O. sumatrensis d’Orchymont. 15. O. thailensis sp. n. Scale bar = 1 mm.

FIGURES 1 – 6. Oocyclus aedeagi, dorsal views. 1. O. viridescens sp. n. 2. O. sitesi sp. n. (holotype). 3. O. namtok sp. n. 4. O. thailensis sp. n. (holotype). 5. O. sumatrensis d’Orchymont (specimen from Thailand). 6. O. melinoventris sp. n. Scale Bar = 0.18 mm.