Oocyclus fikaceki Short & Jia

Short, Andrew Edward Z. & Jia, Feng-Long, 2011, Two new species of Oocyclus Sharp from China with a revised key to the genus for mainland Southeast Asia (Coleoptera: Hydrophilidae), Zootaxa 3012, pp. 64-68 : 65

Oocyclus fikaceki Short & Jia sp. n.

( Figs. 1 , 2 A)

Type material. Holotype (male): CHINA: Fujian Province: Wuyishan, Da’an, Upper Chongyang River, wet cliff, 444.5m elev., 27 57’32”N, 117 51’38”E, 15.vii.2010, leg. F.L. Jia. [original label in Chinese] ( SYSU). Paratypes (179): CHINA: Fujian Province: same data as holotype (5: SYSU, NMPC, USNM). Guangdong Province: Dinghu Nature Reserve, 30.x.2001, ca. 50-150 m, leg. Jäch & Komarek, CWBS 454, (7 exs.: NMW, USNM). Jiangxi Province: Jinggangshan, Zhufeng Mount, 2.x.2010, leg. F.L. Jia (57 exs.: SYSU); same locality, 29.iv.2011, leg. F.L. Jia (11 exs.: SYSU); Shuangxikou, 3.x.2010, leg. F.L. Jia (1 ex.: SYSU); same locality, 24.iv.2011, leg. F.L. Jia (2 exs.: SYSU); Baiyinhu, 23.iv.2011, leg. F.L. Jia (37 exs.: SYSU); same locality but 23- 29.iv.2911, leg. Fikáček, Hajek, & Kubecek, wet rocks in bed of drying stream with algae, MF01 (29 exs.: NMPC, USNM); Dabali, 28.iv.2011, leg. F.L. Jia (20 exs.: SYSU); same date locality but leg. Fikáček, Hajek, Kubecek, Jia, Song, & Zhao, wet rocks, MF16 (8 exs.: NMPC, USNM); Xiping, 24.iv.2011, leg. F.L. Jia (2 exs.: SYSU).

Diagnosis. From most regional species, O. fikaceki can be distinguished by its small to medium size, its rounded posterolateral margins of the pronotum, the lack of procoxal spines, and sparse, long setae on abdominal ventrites 1-4. It is most similar to a group that contains O. sitesi (from which it can be distinguished by the lack of distinct elytral systematic punctures), O. viridescens , (which has microreticulate metafemora, unlike O. fikaceki with smooth metafemora), and O. dinghu (which has uniformly pale maxillary palps, and more finely punctate elytra).

Description. Size and Form. Total body length = 3.8–4.0 mm. Oval, strongly convex. Elytra slightly longer than wide. Color. Dorsum black; head, pronotum and often elytra with a subtle green iridescent sheen. Maxillary and labial palps yellow, with apex of maxillary palpomere darkened. Mentum and stipes light to reddish brown, distinctly paler than ventral face of head. Legs, epipleura, lateral margins of prosternum and posterior half of each ventrite pale yellow to brown, with remainder of venter slightly to moderately darker reddish brown. Head. Ground punctation on labrum, clypeus and frons slightly variable in size from almost undetectable to fine; fairly densely distributed, distance between punctures 0.5–1.5x the width of one puncture. Systematic row of punctures on the labrum very dense, more or less forming a lateral, shallow median groove, and set with a dense row of long erect yellow setae. Frons with an irregular row of systematic punctures mesad of each eye, bearing a few fine setae. Clypeus with a few nearly undetectable systematic punctures along anterolateral margins, slightly larger than surrounding punctation and usually bearing short setae. Maxillary palps very short, subequal in length as 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 and scattered punctures, including two small clusters of punctures mediolaterally that bear fine setae. Thorax. Ground punctation on pronotum and elytra very irregular in size, composed of both extremely fine and moderately coarse punctures, which are generally mixed and evenly distributed. Pronotal systematic punctures present, but blending with larger general punctures, usually not more than 1.5x the size of general punctation and set with a fine recumbent seta. Lateral margins of pronotum appearing without setiferous punctures. 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 the largest of the ground punctures; these rows (of systematic punctures) can be detected by the presence of a fine, short seta. Prosternum with median carina along entire length, with a small blunt tooth anteriorly; 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 two-fifths the total length of the metasternum. Pro- and mesocoxae densely pubescent; without spines. Protibiae with 6-7 spines on dorsal face. Protarsal segments 1–4 small, subequal in length, apical segment slightly shorter than segments 1–4 combined. Metafemora without microreticulation. Abdomen. Ventrites 1–4 with two lateral rows of very long, fine setae; longest setae longer than the setae around the metasternal glabrous area. Fifth ventrite entire; with dense, uniform setae over entire surface. Aedeagus ( Fig. 2 A) with outer margin of parameres slightly curved inwards; median lobe appearing bilobed at apex, with gonopore situated at almost one-gonopore length below it.

Etymology. Named in honor of Dr. Martin Fikáček, curator at the Czech National Insect Collection, and enthusiastic hydrophilid specialist who has collaborated with both the authors.

Distribution. China (Fujian, Guangdong, Jiangxi).

Biology. Found in hygropetric habitats such as wet rock faces.

Figures

FIGURE 1. Oocyclus fikaceki sp. n., dorsal, ventral, and lateral habitus (paratype).

FIGURE 2. Dorsal view of the aedeagus of Oocyclus spp., A) O. fikaceki sp. n., paratype, B) O. dinghu sp. n., holotype (scale bar = 0.25 mm).