Hydraena ampla, Perkins, Philip D., 2011

Perkins, Philip D., 2011, New records and description of fifty-four new species of aquatic beetles in the genus Hydraena Kugelann from South America (Coleoptera: Hydraenidae), Zootaxa 3074, pp. 1-198 : 61

Hydraena ampla , new species

Figs. 126 (habitus), 128 (aedeagus), 164 (spermatheca), 198 (map)

Type Material. Holotype (male): Ecuador: Cotopaxi, Quevedo (66 km E), elev. 1325 m, 1° 3' S, 78° 55' W, 15 i 1978, P. J. Spangler & J. Anderson. Deposited in the USNM. Paratypes (9): Ecuador: Cotopaxi, Same data as holotype (3 USNM); Latacunga, 117 Km W, elev. 914.4 m, 0° 55' S, 79° 12' W, 1 vii 1975, A. Langley & J. Anderson (1 USNM); El Oro, Salvias, seep, elev. 1400 m, 3° 47' S, 79° 21' W, 9 vi 1979, J. Anderson (2 USNM); Napo, San Francisco de Borja, on seep on stream bank, elev. 1610 m, 0° 25' S, 77° 50' W, 17 i 1978, P. J. Spangler & J. Anderson (1 USNM); Pichincha, Quito (60 km SW), roadside ditch, elev. 1900 m, 0° 13' N, 78° 45' W, 8 ix 1990, P. J. Spangler (2 USNM).

Differential Diagnosis. A large, broad, darkly colored species with very small plaques, and males with distinctively modified tibiae. Dorsal habitus somewhat similar to H. cochabamba ( Figs. 126 , 130 ); differing therefrom by the larger size (ca. 1.97 mm vs. 1.59 mm), the broader body, the coarser pronotal punctation, the presence of metaventral plaques, and the modified male tibiae. The male genitalia of these two species, and that of H. manabica , show some similarities in general plan, but differ markedly in many ways ( Figs. 128–129, 132).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.97/0.92; head 0.28/0.46; pronotum 0.47/0.71, PA 0.49, PB 0.62; elytra 1.24/0.92. Dorsum dark brown to piceous, darkest on head and pronotal disc; legs brown; maxillary palpi light brown, tip not darker. Body form broad.

Frons punctures near eyes ca. 1–2xef, much sparser but not appreciably smaller medially; interstices shining, ca. 0.5–1xpd laterally, 2–6xpd medially, midline nearly impunctate. Clypeus microreticulate laterally, very finely sparsely punctulate medially. Mentum moderately coarsely, moderately densely punctulate, effacedly microreticulate, dull; postmentum anteriorly very finely sparsely punctulate, shining, posteriorly densely micropunctulate, dull. Genae raised, shining, without posterior ridge.

Pronotum weakly arcuate laterally; anterior margin straight behind eyes, emarginate behind frons, scintilla absent; punctures on disc ca. 1xpd largest punctures on frons, interstices shining, 1–4xpd medially, punctures larger and much denser at anterior, posterior and laterally; PF1 and PF2 absent; PF3 large and quite deep; PF4 shallow.

Elytra arcuate laterally; summit of posterior declivity before midlength; lateral explanate margins moderately wide; on basal 1/3 punctures slightly smaller than largest pronotal punctures, punctures becoming finer and more widely spaced toward posterior. Intervals not raised, shining, on basal 1/3 ca. 1–2xpd, as are interstices between punctures of a row, a few punctures subserial. Apices in dorsal aspect conjointly broadly rounded, in posterior aspect margins forming shallow angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 2/1/3/7. P1 laminate; median carina sinuate in profile. P2 l/ w ca. 7/2, sides slightly converging toward blunt apex, apex raised slightly above mesoventral intercoxal process. Plaques very small, parallel, not raised, located at sides of deep median depression. Metaventrite with very small point extended posteriorly from margin of each mesocoxal cavity. AIS width at straight posterior margin ca. 2x P2. Protibia arcuate, markedly widened in distal 1/2 where medial margin sharp, except narrowed subapically between small tooth and apex. Mesotibia arcuate, lateral margin with row of stout spines. Metatibia slender, arcuate over distal 3/4. All tarsi with small cluster of setae on basal tarsomeres. Pro- and mesotarsi with last tarsomere arcuate. Male abdominal apex symmetrical; last tergite vertical, with small apicomedian notch. Female (microslide mount, n=1): last tergite sharply rounded, apicomedian notch very shallow, ca. 16 non-hooked, slightly flattened setae, apicomedian gap moderately wide; gonocoxite not midlongitudinally divided, apical margin sharply rounded, weak transverse ridge evident at border of microreticulation ( Fig. 164 ); spermatheca type C2, process small, accessory gland cup one-sided.

Etymology. Named in reference to the wide body form.

Distribution. Currently known from several localities in Ecuador ( Fig. 198).

Figures

FIGURE 126. Hydraena ampla, holotype, dorsal and lateral habitus, and venter.

FIGURE 130. Hydraena cochabamba, holotype, dorsal and lateral habitus, and venter.

FIGURES 163 – 166. Female tergite X and gonocoxite of Hydraena species.