Hydraena (Hydraenopsis) saintvincentensis, Perkins, 2023

Perkins, Philip D., 2023, New Neotropical and Nearctic species of water beetles in the genera Hydraena Kugelann and Ochthebius Leach, a key to North American genera and subgenera of the family, new distribution records, and a synopsis of ecology, behavior and morphology related to aquatic life (Coleoptera: Hydraenidae), Zootaxa 5367 (1), pp. 1-86 : 50-52

Hydraena (Hydraenopsis) saintvincentensis , new species

Figs. 2 (habitus comparison), 29 (habitus and aedeagus)

Type Material. Holotype (male): “WEST INDIES: St. Vincent Hermitage Forest , E of Spring Village, N13°14.86’ W61°12.77’ 16–27.VIII.2006, forest edge malaise, 340 m, S. & J. Peck, 06-104A” ( CMNO) . Paratypes: same locality, forest edge, flight intercept trap, 16– 27.viii. 2006, leg. S. & J. Peck, 06-104B (1 CMNO) ; same locality, flight intercept trap, forest, 16– 27.viii. 2006, leg. S. & J. Peck 06-105) (1 CMNO) .

Differential Diagnosis. This member of the H. marginicollis Subgroup (see Perkins 1980: 69, 164) is a small, rather narrow species with a pronotal macula, very narrow mesoventral intercoxal process, and metaventral plaques absent or very indistinct, very finely punctulate. Reliable differentiation from other members of the Subgroup will require dissection of males and careful examination of the aedeagus ( Fig. 29 ).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.40/0.57; head width 0.34; pronotum 0.35/0.48, PA 0.39, PB 0.41; elytra 0.84/0.57. Habitus as illustrated ( Fig. 29 ). Dorsum with head dark brown to black, pronotum with distinctive dark brown macula surrounded by wide light brown to testaceous margins, elytra brown, palpi testaceous, tip of last palpomere not darker. Dorsum of head and pronotum moderately finely moderately densely punctulate, more sparsely punctulate on macula than on surrounding areas, interstices shining; each dorsal puncture with short recumbent seta; punctures of frons disc and pronotal disc ca. 1xef, interstices on pronotal disc ca. 1–3xpd; punctures of clypeus very fine, lateral areas microreticulate. Labrum apicomedially excised, free margins weakly upturned. Pronotum with anterior margin weakly emarginate over middle 1/2; anterolateral pronotal fovea moderately deep, other usual foveae absent

Elytra with summit of posterior declivity at ca. midlength; lateral explanate margins narrow; on basal 1/3 punctures ca. 1xpd of largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, width ca. 1–2xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins forming very shallow angle with one another.

Venter: Mentum densely finely punctulate, dull; postmentum very finely densely micropunctulate in median concavity, surrounding areas smooth, shining. Genae raised, shining, without posterior ridge. P1 laminate; median carina sinuate in profile. P2 very narrow, l/w ca. 5/1, sides markedly converging toward blunt apex, apex raised slightly above mesoventral intercoxal process. Plaques absent or very indistinct, finely punctulate, median depression deep. AIS width at straight posterior margin ca. 3x P2. All tibiae straight, slender. Abdominal apex symmetrical; last tergite with apicomedian notch.

Distribution. Currently known only from the type locality.

Etymology. Named in reference to the known geographical distribution.

New species from U.S.A.

Figures

FIGURE 2. Dorsal habitus of Hydraena species.

FIGURE 29. Hydraena (Hydraenopsis) saintvincentensis, new species, holotype habitus and aedeagus.