Hydraena peckorum, 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 : 36-37

Hydraena peckorum , new species

Figs. 56 (habitus), 58 (aedeagus), 177 (spermatheca), 197 (map)

Type Material. Holotype (male): Argentina: Salta, 17 km N La Caldera, Alto de la Sierra, subtropical humid forest, malaise-FIT, elev. 1550 m, 24° 27' S, 65° 23' W, 2–30 xii 1987, S. & J. Peck. Deposited in the CMNO. Paratypes (46): Argentina: Jujuy, Calilegua National Park, El Cortaderal, km 6, forest malaise-FIT, elev. 800 m, 23° 45' S, 64° 51' W, 18–28 xii 1987, S. & J. Peck (4 CMNO); Calilegua National Park, Estaca El Cero, forest malaise- FIT, elev. 900 m, 23° 45' S, 64° 51' W, 18–28 xii 1987, S. & J. Peck (4 CMNO); Salta, 17 km N La Caldera, Alto de la Sierra, subtropical humid forest, malaise-FIT, elev. 1550 m, 24° 27' S, 65° 23' W, 2–30 xii 1987, S. & J. Peck (9 CMNO); 22 km N La Caldera, El Ucumar, subtropical humid forest, malaise-FIT, elev. 1550 m, 2–30 xii 1987, S. & J. Peck (12 CMNO); 45 km W. Salta, El Alisal, moist ravine thicket, malaise-FIT, elev. 1950 m, 1–29 xii 1987, S. & J. Peck (11 CMNO); El Rey National Park, Pozo Verde Trail, km 5, Yungas forest, malaise-FIT, elev. 950 m, 5–15 xii 1987, S. & J. Peck (3 CMNO); El Rey National Park, Pozo Verde Trail, km 7, Yungas forest, Mal. -FIT, elev. 1000 m, 5–15 xii 1987, S. & J. Peck (3 CMNO).

Differential Diagnosis. A medium sized species with relatively strongly arcuate lateral margins of the pronotum, with a very indistinct scintilla, and with a wide explanate margin of the elytra. In mature specimens the pronotum does not have a distinct fascia, but this color pattern will be apparent in at least some teneral specimens. Somewhat similar in dorsal habitus and ventral structure to H. atroscintilla ( Figs. 53 , 56 ); differentiated therefrom by the more angulate sides of pronotum, the slightly deeper PF2, and the wider explanate margin of the elytra. The unusual aedeagus cannot be confused with any other known American Hydraena , but does show some similarity in basic plan to that of H. atroscintilla ( Figs. 55, 58). In both species the female last tergite has non-hooked setae.

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.69/0.74; head 0.30/0.41; pronotum 0.42/0.59, PA 0.45, PB 0.52; elytra 1.02/0.74. Dorsum of head dark brown to piceous; pronotum dark brown on disc, surrounding areas brown; elytra dark brown; legs brown; maxillary palpi testaceous, tip not darker.

Frons punctures ca. 0.5–1xef, larger and denser near eyes than medially; interstices laterally microreticulate, ca. 0.5–1xpd, medially shining, ca. 1–3xpd. Clypeus microreticulate laterally, very finely sparsely punctulate medially. Mentum and postmentum very sparsely very finely punctulate, shining. Genae raised, shining, without posterior ridge.

Pronotum strongly arcuate laterally; anterior margin straight behind eyes, emarginate behind frons, very slightly, if at all, produced in middle, with very indistinct scintilla; punctures on disc larger and deeper than those on frons, interstices weakly shining, 1–3xpd on disc, punctures larger and denser at anterior and posterior, sparser at slightly raised lateral margin of PF2; PF1 very shallow or absent; PF2 shallow; PF3 very deep; PF4 moderately deep; PF3 and PF4 broadly confluent.

Elytra moderately arcuate laterally; summit of posterior declivity slightly behind midlength; lateral explanate margins wide; on basal 1/3 punctures ca. 1xpd largest pronotal punctures, punctures becoming slightly smaller and more widely spaced toward posterior. Intervals not raised, weakly 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 rounded, in posterior aspect margins forming very shallow angle with one another.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 2/2.5/6/4. P1 laminate; median carina sinuate in profile. P2 l/w ca. 5/2, sides parallel, apex blunt, raised slightly above mesoventral intercoxal process. Plaques moderately wide, straight, narrowing anteriorly, weakly raised, located at sides of median depression. Metaventrite with very short longitudinal ridge on each side, extended posteriorly from margin of each mesocoxal cavity. AIS width at straight posterior margin ca. 2x P2. Protibia very slightly arcuate, median margin with small tooth at ca. midlength, margin narrower between tooth and apex Meso- and metatibia slender, straight. Male abdominal apex asymmetrical; last tergite with large deep notch, offset to right side. Female (microslide mount, n=1): last tergite sharply rounded, with minute apicomedian notch, setae very small, not hooked; gonocoxite not midlongitudinally divided, apical margin sharply rounded, low transverse ridge evident at border of microreticulation; spermatheca type C2. Etymology. Named in honor of the collectors, Stewart and Jarmila Peck.

Distribution. Currently known from the type locality and a few nearby sites ( Fig. 197). Note. The illustration of the spermatheca ( Fig. 177 ) is not drawn in a completely flat plane; in reality the spermatheca is shaped more like an "open" C.

Figures

FIGURE 53. Hydraena atroscintilla, holotype, dorsal and lateral habitus, and venter.

FIGURE 56. Hydraena peckorum, holotype, dorsal and lateral habitus, and venter.

FIGURES 174 – 178. Spermathecae of Hydraena species.