Hydraena (Hydraenopsis) comicala, 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 : 52-55

Hydraena (Hydraenopsis) comicala , new species

Figs. 1 (habitus comparison), 31 (habitus and aedeagus)

Type Material. Holotype (male): U.S.A.: “ ARIZONA Santa Cruz Co. Canelo 28 March 1970 K. Stephan coll.” ( 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 narrow and parallel metaventral plaques (P2/w/l/s ca. 1/1/3/1), and the aedeagal morphology ( Fig. 31 ). Males are additionally recognized by the metatibiae, which are weakly arcuate in the distal ½. Reliable determinations will require dissection of males.

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.50/0.64; head width 0.37; pronotum 0.37/0.52, PA 0.42, PB 0.52; elytra 0.94/0.64. Habitus as illustrated ( Fig. 31 ). Dorsum with head dark brown to black, pronotum with distinctive dark brown macula surrounded by wide brown margins, elytra brown, palpi testaceous, tip of last palpomere not darker, legs testaceous. Dorsum of head and pronotum moderately finely moderately densely punctulate, more sparsely punctulate on macula than on surrounding areas, interstices shining; punctures of frons disc and pronotal disc ca. 1–2xef, interstices on pronotal disc ca. 1–3xpd; clypeus disc impunctate or nearly so, strongly 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 moderately deep, other usual foveae absent.

Elytra with summit of posterior declivity slightly past midlength; lateral explanate margins moderately wide; on basal 1/3 punctures ca. 1.5xpd 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 moderately deep angle with one another.

Venter: Mentum moderately densely finely punctulate, interstices weakly shining; postmentum very finely densely micropunctulate, dull. Genae raised, shining, without posterior ridge. Ratios of P2 width and plaque shape (P2/w/l/s) ca. 1/1/3/1. P1 laminate; median carina sinuate in profile. P2 l/w ca. 3/1, apex blunt, apex raised slightly above mesoventral intercoxal process. Plaques parallel, dull, finely punctulate, median depression deep. AIS width at straight posterior margin ca. 2x P2. Pro- and mesotibiae straight, slender. Metatibiae weakly arcuate in distal ½. Abdominal apex symmetrical; last tergite apically rounded.

Distribution. Currently known only from the type locality.

Etymology. Named in reference to the aedeagus in lateral view, which gives the impression of a jester-like profile, wearing a comical hat.

Figures

FIGURE 1. Dorsal habitus of Hydraena species.

FIGURE 31. Hydraena (Hydraenopsis) comicala, new species, holotype habitus and aedeagus.