Hydraena multispina, 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 : 22-23

Hydraena multispina , new species

Figs. 21 (habitus), 41 (aedeagus), 150 (female abd.), 158 (spermatheca), 194 (map)

Type Material. Holotype (male): Peru : Cuzco, Quita Calzone (at km 164), elev. 1030 m, 13° 9' S, 71° 22' W, 3 ix 1989, R. A. Faitoute. Deposited in the USNM. Paratypes (6): Same data as holotype (3 USNM). Ecuador: Pastaza Province, Puyo, Santa Clara, Rio Llaudio Chico, elev. 600 m, 1° 17' S, 77° 54' W, 10 i 1995, Gerecke (3 NMW).

Differential Diagnosis. Differentiated from all other species of American Hydraena , except H. cordispina , by the spinose elytral apices and spinose labrum ( Figs. 21–22 ). The elytra have only five series of punctures between the suture and the humeral umbo. Differing from H. cordispina by the broader body form, the more ovoid and more convex elytra with more widely separated serial rows of punctures, among other characters. The spermathecae of the two species also distinctively differ ( Figs. 158–159). Females are unusual in that the long setae on 5th abdominal ventrite are in two patches, one on each side ( Fig. 150 ). The aedeagus of H. multispina differs markedly from any other known American Hydraena ( Fig. 41).

Description. Size: holotype (length/width, mm): body (length to elytral apices) 1.19/0.55; head 0.19/0.31; pronotum 0.32/0.41, PA 0.33, PB 0.29; elytra 0.71/0.55. Dorsum of head with frons piceous, remainder of dorsum dark reddish brown; maxillary palpi testaceous, tip not darker.

Eyes small. Frons microreticulate and coarsely punctate near eyes; medially very finely sparsely punctulate, shining, interstices ca. 3–6xpd. Clypeus microreticulate laterally, very finely sparsely punctulate medially. Labrum with median incision deep, anterior margin of each lobe straight, except lateral angle produced in sharp point. Mentum with sparse, very short setae, shining; postmentum very finely micropunctulate and with very sparse, short setae, shining. Genae weakly raised, shining, carinate laterally, without posterior ridge.

Pronotum strongly cordiform, much narrower at base than at midlength, posterior angles slightly obtuse; anterior margin weakly emarginate from side to side, scintilla absent; punctures on disc much larger and deeper than those medially on frons, interstices shining, 1–5xpd, punctures larger and denser at anterior and posterior; PF1 and PF2 absent; PF3 shallow; PF4 very shallow, almost obsolete.

Elytra very convex, appearing humped, summit of posterior declivity at ca. basal 1/3; lateral explanate margins wide; lateral margin in posterior 1/3 with spinose processes, ca. 10 on each side, becoming gradually larger toward posterior; five series of punctures between suture and humeral umbo; on basal 1/2 punctures ca. 1xpd largest pronotal punctures, punctures becoming finer and much more widely spaced toward posterior. Intervals not raised, shining, on basal 1/2 ca. 4–5xpd, interstices between punctures of a row slightly smaller. Apices in dorsal aspect rather sharply conjointly rounded, in posterior aspect margins do not form angle with one another. Elytra fused; brachypterous, wings ca. 1/2 length of elytra; flightless.

Ratios of P2 width and plaque shape (P2/w/l/s) ca. 4/2.5/10/4. P1 as wide as P2; median carina low, ended between mesocoxae, very weakly emarginate in profile. P2 raised, l/w ca. 2/1, sides slightly converging toward blunt apex. Plaques wide, widest at midlength, tapering anteriorly and posteriorly, converging and very narrowly separated anteriorly, weakly raised, conjointly forming inverted V-shape, located at sides of deep median depression. Metaventrite transversely convex, with very weak short longitudinal ridge on each side, extended posteriorly from margin of each mesocoxal cavity. AIS deeply concave, width at posterior margin ca. 1.5x P2. Protibia very slightly arcuate. Mesotibia more strongly arcuate, gradually widened form base to near apex, distal 1/4 with short setae on medial margin. Metatibia straight, distal 1/2 with short setae along medial margin. Male abdominal apex very slightly, if at all, asymmetrical. Female (microslide mount, n=1): last tergite sharply rounded, without apicomedian notch, ca. 26 well hooked, long setae in contiguous row; gonocoxite divided by weakly sclerotized midlongitudinal area, apical margin broadly rounded, lacking transverse ridge ( Fig. 150 ); spermatheca not C-type, duct comparatively short ( Fig. 158). Female 5th ventrite with long setae in two patches, one on each side.

Etymology. Named in reference to the spinose labrum and elytra.

Distribution. Currently known from Ecuador and Peru ( Fig. 194 ).

Notes. Given the fact that the known specimens are flightless, have fused elytra, and are brachypterous, it is a great surprise to find this species in both Peru and Ecuador. However, the three specimens from Ecuador, all males, have the aedeagus differing only in the most minute, insignificant details from that of the holotype. It is possible that the Ecuadorian specimens have incorrect locality labels.

Figures

FIGURE 21. Hydraena multispina, holotype, dorsal and lateral habitus, and venter.

FIGURE 22. Hydraena cordispina, holotype female, dorsal and lateral habitus, and venter.

FIGURES 148 – 150. Female terminal abdominal segments of Hydraena species.

FIGURES 193 – 194. 193. Geographical distributions of species in the Paeminosa Group. 194. Geographical distributions of species in the Curvosa and Multispina Groups.