Oocyclus ancho, Short & Torres-Gavosto & Hettinger, 2023

Short, Andrew E. Z., Torres-Gavosto, Juan Martin & Hettinger, Ty, 2023, A review of the Oocyclus Sharp of Ecuador with description of 12 new species (Coleoptera: Hydrophilidae: Laccobiini), Zootaxa 5277 (1), pp. 91-112 : 93-95

Oocyclus ancho sp. n.

( Figs. 1A , 5H , 7 )

Type material. Holotype (male): ECUADOR, Tung./ Banos (18kms.E)/ 25Jan.1976, 5130′/ Spangler et al. ”, “Seepage over/rock outcrops/ in roadcuts”, “ECUADOR-PEACE CORPS./SMITHSONIAN INSTITUTION/ AQUATIC INSECT SURVEY” ( USNM) . Paratypes 72 exs.): ECUADOR: Tungurahua Province: Same data as holotype (53 exs., USNM, SEMC); 20 km E. Baños , 28.i.1976, seepage over rock in roadcuts, leg. Spangler et al. (15 exs., USNM, SEMC); Along Hwy E. of Baños , 20.v.2008, leg. A.E.Z. Short, seepage by road, AS-08-002 (4 exs., PUCE, SEMC).

Diagnosis. Smaller species. Posterolateral corners of pronotum rounded. Prosternal carinae without spines. Elytra without distinct coarse rows of punctures, though may faint rows may be detected by the sparse punctures usually decumbant setae. Elytral margins not explanate, without a fringe of long setae. Abdominal ventrites light to medium brown.

Of smaller species in Ecuador with rounded anterolateral corners of the pronotum, this species is most similar to O. kichwa , from which it can be separated by the unusually wide median lobe of the aedeagus ( Fig. 5H ).

Description. Size and Form. Length = 3.1–3.8 mm. Body oval, moderately convex ( Fig. 1A ). Color. Dorsum of head, pronotum, and elytra black, with faint iridescent green reflections. Anterolateral margins of pronotum without pale spot. Elytra without distinct maculae. Maxillary and labial palps yellow. Mentum and stipes light brown, lighter in color to the venter of the head. Thoracic ventrites dark brown. Abdominal ventrites and legs light to medium brown. Head. Ground punctation on labrum, clypeus and frons moderately fine, distance between punctures 1.0–2.0× the width of one puncture. Systematic punctures on labrum consisting of several indistinct punctures, sometimes bearing a short seta. Frons with an irregular row of systematic punctures bearing very fine setae mesad of each eye. Clypeus with a few very indistinct systematic punctures along anterolateral margins, slightly larger than surrounding punctation. Maxillary palps short, about as long as width of labrum; segment 2 slightly bulbous, apical segment approximately the same length as penultimate. Labial palps less than half as long as width of mentum. Mentum quadrate and mostly smooth, anterior margin slightly convex and depressed. Thorax. Ground punctation on pronotum and elytra composed of very fine, evenly distributed punctures. Pronotal systematic punctures with short fine setae, at least 2x the size of surrounding ground punctures, anterior and posterior series each forming an irregular field. Lateral margins of pronotum set with a few sparsely distributed setiferous punctures, but margin not appearing fringed. Posterolateral corners of pronotum rounded. Sutural punctation on elytra absent or unmodified from ground punctation; sutural interval not raised in posterior half. Elytra with five rows of nearly indetectable systematic punctures, which are equal in size to the surrounding ground punctation. Each row very sparse, with some punctures very a short fine seta which may be erect but usually decumbent. Prosternum with a clearly defined median carina; slightly elevated anteromedially, the elevation not set with spines or long setae. Elevated process of the mesoventrite rounded, roughly as long as wide; surface nearly flat; set with 5 thickened, coarse spines. Metaventrite with oval glabrous area posteromedially, about as long as wide, length of glabrous area about half as long as length of metaventrite. Procoxae covered with dense pubescence. Protibiae with 7–9 spines on dorsal face. Abdomen. Ventrites covered with fine setae, the longest setae as long or longer in length as the longest setae surrounding the glabrous area of the metaventrite. Aedeagus as in Figure 5H .

Etymology. Ancho, the Spanish word for “wide”, in reference to the very broad median lobe of the aedeagus.

Distribution. Known from a cluster of very closely situated localities in the central Ecuadorian state of Tungurahua ( Fig. 7 ).

Figures

FIGURE 1. Dorsal, ventral and lateral habitus views of Oocyclus species. (A) ancho sp. n. (B) zamora sp. n. (C) yantzaza sp. n.

FIGURE 5. Aedeagi of Oocyclus species in Ecuador with rounded posterolateral corners of the pronotum. (A) rupestris sp. n. (B) sharpi, paratype from Costa Rica (C) sharpi, specimen from Ecuador (D) sharpi, specimen from Ecuador (E) kichwa sp. n. (F) kichwa sp. n. (G) yantzaza sp. n. (H) ancho sp. n.

FIGURE 7. Distribution of Oocyclus spp. in Ecuador.