Oocyclus sumak, 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 : 105

Oocyclus sumak sp. n.

( Figs. 2B , 6D , 7 )

Type Material: Holotype (Male): “ ECUADOR: Loja;/ Loja (18km N)/ 1900m, 28Nov1978 / Joseph Anderson”, “ECUADOR-PEACE/ CORPS—SMITHSONIAN/ INSTITUTION AQUATIC/ INSECT SURVEY” ( USNM) . Paratypes (36 exs.): ECUADOR: Loja Province: Same data as holotype (25 exs., USNM, SEMC) . El Oro Province: Salvias , 1400 m, 9.vi.1979, leg. J.J. Anderson (11 exs., USNM, SEMC) .

Diagnosis. Smaller species. Posterolateral corners of pronotum strongly spinose. Prosternal carinae set with a pair of spines anteriorly. Elytra with the first row of systematic punctures bearing a sparse line of erect setae along its entire length. Elytral margins not explanate, without a fringe of long setae. Abdominal ventrites dark brown.

Among Ecuadorian species with spinose posterolateral margins of the pronotum, this species can be distinguished from most others by it smaller size (>4.0 mm) and the presence of bright blue elytral maculae. It is most similar to O. ankas but that species has a smaller pale anterolateral spot on the pronotum and possesses a dense, erect clump of setae at the anterior end of the first row of elytral systematic punctures.

Description. Size and Form. Length = 3.5–4.0 mm. Body oval, slightly convex ( Fig. 2B ). Color. Dorsum of head, pronotum, and elytra black, with bright iridescent green reflections. Anterolateral margins of pronotum with distinct pale spot, extending one-third to one-half the length of the margin. Elytra with distinct iridescent blue, purple and/or green maculae with defuse borders. Maxillary and labial palps yellow. Mentum and stipes brown, slightly paler in color than the venter of the head. Thoracic and abdominal ventrites dark brown. Legs medium to light 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 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 slightly rugose, anterior margin slightly convex and depressed. Thorax. Ground punctation on pronotum and elytra composed of fine, evenly distributed punctures. Pronotal systematic punctures blending with surrounding ground punctation, usually bearing a very fine seta. Lateral margins of pronotum set with a few sparsely distributed setiferous punctures. Posterolateral corners of pronotum strongly spinose. Sutural punctation on elytra absent or unmodified from ground punctation; sutural interval not raised in posterior half. Elytra with five irregular rows of systematic punctures: the first row is represented by sparse line of punctures bearing erect setae along its entire length. Rows 2–5 are represented by irregular series of large coarse punctures usually bearing a very fine recumbent seta; some setae in row 2 may be erect anteriorally. Prosternum with a clearly defined median carina; slightly elevated anteromedially, the elevation set with two long spines. Elevated process of the mesoventrite narrow and elongate, more than three times as long as wide; surface nearly flat; set with 5 thickened, coarse spines. Metaventrite with oval glabrous area posteromedially, ca. twice as long as wide, length of glabrous extending more than half the length of the metaventrite. Procoxae covered with dense pubescence and set with long spines. Protibiae with 9–11 spines on dorsal face. Abdomen. Ventrites covered with short, fine, setae, the longest setae not longer than the longest setae surrounding the glabrous area of the metaventrite. Aedeagus as in Figure 6D .

Etymology. Sumak is the Kichwa word for beautiful, referring to the lovely dorsal coloration of this species.

Distribution. Known from a pair of localities in the south of Ecuador ( Fig. 7 ).

Figures

FIGURE 2. Dorsal, ventral and lateral habitus views of Oocyclus species. (A) ankas sp. n. (B) sumak sp. n.

FIGURE 6. Aedeagi of Oocyclus species in Ecuador with angulate or spinose posterolateral corners of the pronotum. (A) ustulatus sp. n. (B) radiatus sp. n. (C) pakcha sp. n. (D) sumak sp. n. (E) ankas sp. n. (F) lepidus sp. n. (G) bellus sp. n. (H) zamora sp. n. (I) specimen of the morgani/trujillo species group (J) specimen of the morgani/trujillo species group.

FIGURE 7. Distribution of Oocyclus spp. in Ecuador.