Hydraena (Hydraenopsis) temascaltepecica, 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 : 30

Hydraena (Hydraenopsis) temascaltepecica , new species

Figs. 3 (habitus comparison), 16 (habitus and aedeagus)

Type Material. Holotype (male): “ MEXICO: Estado de México, Temascaltepec, Real de Arriba , 21.iv.2004, 19°02’22’’N, 99°59’58’’W, 1950 m, R. Arce col.” ( IEXA) . Paratypes (18): Estado de México, Nezahualcóyotl, Tamazuchale , 21.iv.2004, 19°03’12’’W, 100°01’83’’W, 1850 m, s/colector (1 IEXA) : Estado de México, Villa Guerrero, Totolmajac , 16.iv.1990, 18°55’08’’ N, 99°40’54’’W, 2010 m, Arroyito, R. Arce col. (7 IEXA) ; Mexico, NE of Temascaltepec, Rio Verde , 1830 m, 21 iv 2004, coll. William D. Shepard (10 MCZ) .

Differential Diagnosis. This new species is a member of the H. leechi Group, H. scintillabella Subgroup , the group of species that have a pronotal scintilla, and the males lack metatibial brushes ( Perkins 1980: 36). Members will key to couplet 23 in Perkins (1980: 67). This species can be recognized by the combination of the pronotum with a scintilla, the pronotal foveae deep, the metaventral plaques very narrow, very indistinct or absent, the metatibia of males very slightly arcuate, and the aedeagus ( Fig. 16 ). The aedeagal parameres have the ventromedial margins close together and parallel, which is similar to the parameres of H. scopula Perkins (fig. 36A in Perkins 1980); however, the shapes of the parameres in lateral views and the shape of the distal part of the main-piece differ in the two species. Reliable identifications will require dissection of males and careful examination of the aedeagus.

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.70/0.72; head width 0.41; pronotum 0.42/0.58, PA 0.47, PB 0.46; elytra 1.05/0.72. Habitus as illustrated ( Fig. 16 ). Dorsum dark brown, palpi brown, tip of last palpomere not darker. Dorsum of head and pronotum coarsely very densely punctate, interstices shining; punctures of frons disc and pronotal disc ca. 2–4xef, interstices narrow walls to ca. 1xpd; punctures of clypeus moderately fine, lateral areas microreticulate. Labrum apicomedially excised, free margins weakly upturned. Pronotum with anterior margin weakly emarginate over middle ½, scintilla large; anterolateral, posterolateral and posteromedial pronotal foveae deep; anterior ½ of disc with shallow transverse impression.

Elytra with summit of posterior declivity at or near posterior 1/3; lateral explanate margins wide; on basal 1/3 punctures slightly smaller than 1xpd of largest pronotal punctures, punctures becoming gradually smaller toward posterior. Intervals not raised, width ca. 1xpd, as are interstices between punctures of a row. Apices in dorsal aspect separately rounded, in posterior aspect margins forming deep angle with one another.

Venter: Mentum sparsely very finely punctulate, shining; postmentum very finely densely micropunctulate in median concavity, surrounding areas smooth, shining. Genae raised, shining, posterior margin slightly raised laterally. P1 laminate; median carina sinuate in profile. P2 l/w ca. 3/1, sides slightly converging toward blunt apex, apex raised slightly above mesoventral intercoxal process. Plaques very narrow, very indistinct or absent, located at sides of deep median depression. AIS width at straight posterior margin ca. 3x P2. Pro- and mesotibiae slender, straight. Metatibia very slightly arcuate, gradually slightly increasing in width from base to apex. Abdominal apex symmetrical; last tergite with very shallow apicomedian notch.

Distribution. Currently known only from the type locality.

Etymology. Named in reference to the known geographical distribution.

Figures

FIGURE 3. Dorsal habitus of Hydraena species, H. leechi Group.

FIGURE 16. Hydraena (Hydraenopsis) temascaltepecica new species, holotype habitus and aedeagus.