Oocyclus yantzaza, 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 : 106-109

Oocyclus yantzaza sp. n.

( Figs. 1C , 5G , 7 )

Type material. Holotype (male): ECUADOR, Zamora-/ Chinchipe/ Yantzaza/ 7 November 1979 / Jos. J. Anderson ”, “Collected from/ Seep in Forest / Upper Rio Yantzaza ” ( USNM) . Paratypes (7 exs.): ECUADOR: Zamora-Chinchipe Province : same data as holotype (7 exs., USNM, SEMC) .

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

The smallest species in Ecuador, it is most similar to other relatively small species with rounded posterolateral such as O. kichwa and O. ancho , but these lack a pale posterolateral corners of the pronotum. Additionally, O. yantzaza has a mesoventral process bearing distinct spines, while the somewhat similar O. hakcha has a mesoventral process bearing only thin hairs.

Description. Size and Form. Length = 2.8–3.1 mm. Body oval, moderately convex ( Fig. 1C ). Color. Dorsum of head, pronotum, and elytra black, with faint iridescent green reflections. Anterolateral margins of pronotum with very small pale spot, almost not distinguishable in some a few specimens. Elytra with a few faint green iridescent maculae. Maxillary and labial palps yellow. Mentum and stipes light brown, lighter in color to the venter of the head. Thoracic and abdominal ventrites medium brown. Legs light brown, paler than the rest of the venter. 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 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 very fine decumbent setae, only slightly larger than surrounding ground punctation. Lateral margins of pronotum set with a few sparsely distributed setiferous punctures, creating a fringed appearance. Posterolateral corners of pronotum broadly 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, ca. as long as wide, length of glabrous area roughly half of the 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 roughly equal in length to slightly longer than the longest setae surrounding the glabrous area of the metaventrite. Aedeagus as in Figure 5G .

Etymology. Named after the town in which it was found

Distribution. Known only from the type locality in the south of Ecuador ( 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.