Hydraena (Hydraenopsis) josefinae, Benetti & Valladares & Delgado & Hamada, 2020

Benetti, Cesar J., Valladares, Luis F., Delgado, Juan A. & Hamada, Neusa, 2020, Two new species of Hydraena Kugelann, 1794 from Brazil (Coleoptera: Hydraenidae), Zootaxa 4750 (3), pp. 391-402 : 392-398

Hydraena (Hydraenopsis) josefinae sp. n.

( Figs 1 , 2 , 5 , 8 )

Type locality. BRAZIL, Amapá State, Laranjal do Jari municipality (county), Cerrado , stream (Igarapé) , 00°27’36.1’’N; 52°07’52.7’’W, 36 m.

Type material. Holotype (male): “ BRAZIL: Amapá state, Laranjal do Jari. / Cerrado , stream, 36 m. a.s.l. / 00°27’36.1’’N; W 52°07’52.7’’ W; 6/viii/2011 / A. Pes, P. Cruz, A. Fernandes, & N. Hamada, leg. // ♂ // HOLO- TYPUS [red label] // Hydraena (Hydraenopsis) josefinae sp.n. ” (genitalia extracted and mounted on same card) ( INPA) . Paratype: 1 female. Same data of holotype except: // ♀ // PARATYPUS [red label] (genitalia extracted and mounted on same card) ( INPA) .

Type depository. Instituto Nacional de Pesquisas da Amazônia , Manaus, Brazil

Description. Habitus as in Fig. 1 . Size: Holotype: Male BL 1.35 mm; EL 0.82 mm; EW 0.60 mm. Paratype: Female BL 1.44 mm; EL 0.86 mm; EW 0.66 mm.

Color ( Fig. 1 ): Head (dorsal) dark brown, labrum brown. Pronotum dark brown on the disc, paler at the sides. Elytra dark brown. Antennae, maxillary palps and legs pale brown, apex of last palpomere of maxillary palps yellowish.

Head: Labrum with a wide apicomedian emargination, with subrectangular lobes and the anterior margin weakly convex. Clypeus with small punctures sparsely arranged, each associated to a small white seta. Frons with dense, coarse punctures and shiny interstices, and a pair of small foveae on posterolateral edge of eyes.

Pronotum: Wider than long, maximum width slightly after the median region. Anterior margin straight behind eyes and slightly arcuate behind frons. Scintilla barely perceptible. Sides weakly convex with margins serrate. Posterior margin straight. Punctures on disc much larger and deeper than those on the frons; interstices wide and shiny. PF1 shallow, PF3 moderately deep, PF2 oval, broad and deep, PF4 broad and deep.

Elytra: Moderate arcuate laterally. Lateral margins widely explanate, especially in the elytra middle length. 9 rows of impressed punctures between suture and shoulder, punctures in rows 1–4 (counting from suture) slightly irregular; size of punctures similar to those of the pronotum or slightly larger. Punctures becoming slightly smaller toward posterior and lateral sides. Intervals not raised, shiny.

Mesoventrite: With a straight carina extended to base of intercoxal process.

Metaventrite: Without plaques.

Legs: of normal shape. Tibiae not enlarged or modified.

Abdomen: Apex symmetrical. Terminal sternite ( Fig. 5E ) subquadrate. Spiculum gastrale lost, apparently with a laminar, basal expansion, probably similar to that of the male of the closely related H. alterra (see Fig. 5F ).

Aedeagus: As in Fig. 2 . Main piece stout distinctly dilated in lateral view. With a medially basal tubercle with rounded contour when observed in lateral view ( Fig. 2A ) and a semi-membranous projection directed to the left in ventral view ( Fig. 2B ); distal lobe robust in ventral ( Fig. 2B ) and lateral ( Fig. 2A ) views, with several very complex lobes surrounding a short flagellum, which bears the gonopore; phallobase asymmetrical. Parameres divergent from main piece in ventral view; left paramere, in lateral view ( Fig. 2A ), spatuliform, basally dilated and with a subtriangular laminar projection. Right paramere, in ventral view, with distal and anterior inner margins laminar, fringed basally ( Fig. 2B ).

Female: Size, shape and color similar to male. Pronotum similar to male; PF1 deep, PF3 very deep with the anterior area widened, PF2 similar to PF3, PF4 deep. Protibiae with the outer edge slightly curved, meso and metatibiae straight.

Female genitalia: Female tergite X ( Fig. 5A ) transverse, with a fringe of bristles moderately developed and a few trichoid lateral setae. Disc glabrous. Basal margin medially pointed. Apical margin narrow and distinctly emarginated medially. Gonocoxite ( Fig. 5B ) semicircular. Ventral plate with two subapical tufts of setae. Dorsal plate symmetrical, slightly surpassing the proximal rim of ventral plate, with two slightly marked, concave, small impressions. Spermatheca as in Figs 5 C–D. Distal portion cup-shaped; central portion c-shaped in lateral view.

Differential diagnosis. The new species is a member of the s cintillabella subgroup of the leechi group ( Perkins 2011). Externally this subgroup is quite variable in shape and coloration. Most of these species are medium sized and have a distinct scintilla ( Perkins 2011) , which is hardly perceptible in H. josefinae sp. n. Compared to the other species in the s cintillabella subgroup, the new species resembles some Amazonian species from Venezuela: H. tobogan Perkins, 2011 ( Perkins 2011, fig. 51) and H. reverberata Perkins, 2011 ( Perkins 2011, fig. 54), but the aedeagus differs markedly from these two species, especially in the case of H. reverberata . The aedeagus of the new species is very similar to that of several species in the costiniceps complex in the scintilabella subgroup, in which the main piece is stout and the assemblage of the main piece, distal lobe and parameres form a “cup set” surrounding a short flagellum bearing the gonopore ( Perkins 2011). In addition, the main piece has a pronounced ventral projection or heel and the right paramere has a laminar border, which resembles a razor edge, especially well observed in ventral view ( Fig. 2B ). Considering the aedeagus, H. josefinae sp. n. is closely related to all these species and especially to H. alterra Perkins, 1980 (see Perkins 1980, fig. 38C) from southeast Brazil. Although this species was not studied in the revision by Perkins (2011), it seems to also be related to the costiniceps complex as it shares the described aedeagal ground plan and the pronotal scintilla ( Fig. 3 ). The main piece of both species is stout and has a moderately developed ventral heel (distally rounded in H. josefinae sp. n. and truncated in H. alterra ). These heels have a lateral sticky structure directed to the right in ventral view ( Figs 2B , 4B ), long and slender in H. alterra and slightly wider in the new species. As in other members of the costiniceps complex, these two species have the right paramere with a laminar edge, basally fimbriate. The left paramere is spatuliform in lateral view, again basally fimbriate in H. alterra ( Fig. 4A ) and with a subtriangular projection in H. josefinae sp. n. ( Fig. 2A ). Externally the new species differs from H. alterra in having shorter elytra and in the general shape of the pronotum, with a well-developed scintilla in H. alterra .

Distribution. Currently only known from the type locality (Laranjal do Jari, Amapá State), northern Brazil, near French Guiana ( Fig. 8 ).

Etymology. This species is named after Josefina Garrido, a good friend and colleague, in gratitude for all the shared moments during our long friendship and in recognition of her contribution to the knowledge of aquatic Coleoptera .

Habitat. The type material was collected in a small stream (1.5–2.0 m wide, 5–15 cm deep) that flows through a savanna landscape in the Amazon Biome at 36 m a.s.l. The recorded water parameters were: temperature 29.6 °C, pH 6.0 and conductivity 8.0 µS/cm. The stream has a bed of gravel, bedrock and stones with frequent riparian roots and associated algae.

Figures

FIGURE 1. Dorsal habitus of Hydraena josefinae sp. n., holotype male. Scale bar = 0.5 mm.

FIGURE 2. Hydraena josefinae sp. n., holotype male. Aedeagus in (A) lateral and (B) ventral view. Gonopore indicated by black arrow. Scale bar = 0.1 mm.

FIGURE 3. Dorsal habitus of Hydraena alterra Perkins, 1980, paratype male. Scale bar = 0.5 mm.

FIGURE 4. Hydraena alterra Perkins, 1980, paratype male. Aedeagus in (A) lateral and (B) ventral view. Gonopore indicated by black arrow. Scale bar = 0.1 mm.

FIGURE 5. Hydraena josefinae sp. n., paratype female: (A) tergite X, (B) gonocoxite and (C, D) spermatheca, two views. Hydraena josefinae sp. n., holotype male: (E) sternite X. Hydraena alterra Perkins, 1980, paratype male: (F) sternite X and spiculum gastrale (broken). Scale bar = 0.1 mm.

FIGURE 8. Map with type localities of H. josefinae sp. n. (red circle) and H. pernambucana sp. n. (red star).