Hydraena (Hydraenopsis) lenticula, 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 : 55-57

Hydraena (Hydraenopsis) lenticula , new species

Figs. 2 (habitus comparison), 32 (habitus and aedeagus)

Type Material. Holotype (male): “ U.S.A.: Florida, Alachua Co., San Felasco Hammock , leaf covered margin of small pond, 15.XII.1979, leg. P. D. Perkins ” ( MCZ) . Paratypes (10): Same data as holotype (1 MCZ) . Arkansas, Garland, Camp Clear Fork , malaise trap, 14 June 2005, leg. Brian Baldwin (1 MCZ) ; same locality, U. V. lights, 20 June 2006, leg. Brian Baldwin (1 MCZ) ; Pulaski Co., Little Rock , blacklight trap, 20 August 2000, leg. Brian Baldwin (1 MCZ) ; same locality, blacklight trap, 28 May 2001, leg. Brian Baldwin (1 MCZ) ; Louisiana, Avoyelles Parish, Coulee des Grues S. of Marksville , 16 October 1981, leg. C. B. Barr. (1 MCZ) ; South Carolina, Florence Co., Florence , 22 July 1954, leg. V. M. Kirk (1 MCZ) ; Richland Co., Gadsden , at U. V. light, 27 June 2002, leg. J. C. Ciegler (1 MCZ) ; Texas, Sam Houst. Nat’l. For. , nr. Stubblefield Lk. Cmpgrd., 15 October 1995, leg. E. G. Riley (219) (2 MCZ) .

Differential Diagnosis. This new species of the H. marginicollis Subgroup (see Perkins 1980: 69, 164) is recognized by the combination of the pronotum lacking a distinct macula, the moderately large, shining metaventral plaques, which are elongate oval, convergent anteriorly, with the posterior separation about twice the anterior separation, and the aedeagal morphology ( Fig. 32 ). Reliable determinations will require dissection of males.

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.34/0.57; head width 0.34; pronotum 0.34/0.46, PA 0.38, PB 0.41; elytra 0.84/0.57. Habitus as illustrated ( Fig. 32 ). Dorsum with head dark brown to black, pronotum with dark brown fascia, moderately wide brown margins anterior and posterior to fascia, elytra dark brown, palpi and legs brown. Dorsum of head and pronotum finely sparsely punctulate, more sparsely punctulate on fascia than on surrounding areas, interstices shining; punctures of frons disc and pronotal disc ca. 1–2xef, interstices on pronotal disc ca. 2–4xpd; clypeus disc impunctate or nearly so, shining, lateral areas microreticulate, dull. Labrum apicomedially excised, free margins weakly upturned. Pronotum with anterior margin weakly emarginate over middle 1/2; anterolateral pronotal foveae deep, other usual foveae absent.

Elytra with summit of posterior declivity slightly past 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. 2–3xpd, as are interstices between punctures of a row. Apices in dorsal aspect conjointly rounded, in posterior aspect margins not forming angle with one another.

Venter: Mentum moderately densely finely punctulate, interstices shining; postmentum very finely very densely micropunctulate, dull. Genae raised, shining, without posterior ridge. Ratios of P2 width and plaque shape (P2/w/l/ s) ca. 1/1.5/3/1.5. P1 laminate; median carina sinuate in profile. P2 moderately wide, l/w ca. 3/1, sides converging toward apex, apex blunt, raised slightly above mesoventral intercoxal process. Plaques moderately large, elongate oval, convergent anteriorly, posterior separation ca. 2x anterior separation, shining, median depression deep. AIS width at straight posterior margin ca. 2x P2. Protibiae very slightly arcuate. Meso- and metatibiae straight, slender. Abdominal apex symmetrical; last tergite with apicomedian notch

Distribution. Currently known from several localities in the southeastern U.S.A.

Etymology. Named in reference to the habitats of this species: small bodies of standing water.

Remarks. The localities cited are each represented by at least one dissected male.

Figures

FIGURE 2. Dorsal habitus of Hydraena species.

FIGURE 32. Hydraena (Hydraenopsis) lenticula, new species, holotype habitus and aedeagus.