Oocyclus substillus, Short, A. E. Z. & Perkins, P. D., 2004

Short, A. E. Z. & Perkins, P. D., 2004, A revision of Oocyclus Sharp of Mexico and Central America (Coleoptera: Hydrophilidae), Zootaxa 783, pp. 1-45 : 19-21

Oocyclus substillus sp. n.

( Figs. 13 , 25 )

Type Locality. Barro Colorado Island, Canal Zone, Panamá.

Type material. Holotype male. “ PANAMA: Canal Zone, Barro/ Colorado Island, 12 vi 1972 / from wet mossy area at drip/ below air conditioner/ coll. R. H. Pine”, “HOLO­ TYPE / Oocyclus / substillus / Short & Perkins” ( USNM). Paratypes (3). Same data as holotype (1 USNM, 1 AEZS, 1 MCZ).

Differential Diagnosis. This species is easily distinguished from all other Central American species by the spinose posterolateral corners of the pronotum.

Description. Size and Form. Total Length= 4.6–4.9mm. EL/EW=1.13. Broadly oval; slightly convex, elytra longer than wide; disc of elytra more convex transversely than longitudinally. Color. Dorsum generally black; anterolateral margin of pronotum pale on anterior third. Elytra with irregular patches of green iridescence. Maxillary and labial palpi yellow. Mentum and stipes brown, only slightly paler than venter of head. Sternum dark brown. Femora dark to medium brown; tibia and tarsi light brown. Epipleura and pseudoepipleura yellow. Each ventrite dark brown with light brown patches laterally. Head. Punctation on frons, clypeus and frons uniformly fine; punctures separated by 1.5– 2 x width of one puncture. Antennae with scape subequal in length to segments 2–5, segment 2 subequal to segments 3–5, segments 4–5 equal in length; first two segments of club equal in size, third segment 1.5x longer. Maxillary palpi slightly shorter than width of labrum; segments 2 and 3 subequal in length, apical segment slightly longer. Labial palpi ¾ length of mentum; apical two segments subequal in length. Labrum without detectable systematic punctures. Clypeus with 4–5 nearly indistinct systematic punctures near each anterolateral margin, usually bearing a short recumbent seta. Frons with an irregular row of systematic punctures mesad of each eye bearing short recumbent setae. Mentum quadrate, anterior margin slightly convex, with scattered spare punctures of mixed size; slightly rugose. Thorax. Dorsal punctation of pronotum and elytra very fine, distance between punctures 1.5–2.5x the width of one puncture. Posterolateral corners of pronotum elongated posteriorly into an acute spine. Lateral martins of pronotum lined with a sparse row of setiferous punctures. Pronotal systematic punctures 2– 3 x larger than general punctation, bearing short recumbent setae, with anterior series forming an irregular row, posterior series forming a diffuse field. Sutural punctation of elytra extremely fine and irregular, not bearing setae. Sutural punctation of elytra extremely fine, not bearing setae. Punctures in elytral rows 2– 3 x the size of general punctuation; first elytral row of punctures dense, especially in anterior half; bearing short usually erect setae. Row 2 and 3 distinct, slightly less dense, bearing recumbent to erect setae. Row 4 less regular; row 5 forming a diffuse field of setiferous punctures between row 4 and elytral margin. Prosternum carinate centrally, with two coarse spines anteromedially, spines shorter than narrowest width of prosternum. Mesosternal process at least 2x longer than wide, with nine coarse spines. Metasternum with elongate­oval glabrous area posteromedially, 2x longer than wide; about 2/3 length of metasternum. Procoxae pubescent and bearing numerous coarse spines, slightly smaller than those of prosternum. Protibia with 9–11 spines on dorsal face. Protarsal segments 1–4 small, subequal in length; segment 5 as long as segments 1–4; protarsal claws of males slightly enlarged. Hind femora glabrous. Abdomen. Ventrites with moderately dense, uniform pubescence, usually suberect to recumbent; longest setae shorter to subequal in length to longest setae around margin of metasternal glabrous area. Fifth exposed ventrite entire. Aedeagus ( Fig. 25 ) with parameres largely straight on outer edge, ventral surfaces slightly wider than dorsal surfaces, tips lightly curved inward. Median lobe wide with the tip bifid, nearly reaching the apex of the parameres; depression on dorsal face of the median lobe re­curved at its base, creating the appearance of a second layer; basal piece narrowed and rounded basally.

Distribution. Panamá.

Etymology. Substillus , L. meaning dribbling, referring to the collecting habitat. It is used here as a noun in apposition.

Discussion. The only known series of this species was collected from the drip of an air conditioner.

Figures

FIGURE 13. Oocyclus substillus n. sp. holotype. Dorsal and lateral habitus.

FIGURES 24 – 27. Oocyclus aedeagi, dorsal views. Scale bars = 0.2 mm. – 24. O. sharpi (holotype). – 25. O. substillus n. sp. (holotype). – 26. O. tapanti n. sp. (holotype). – 27. O. vestitus Sharp (holotype).