Hydraena (Hydraenopsis) pernambucana, 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 : 398-401

Hydraena (Hydraenopsis) pernambucana sp. n.

( Figs 6–8 )

Type locality. Brazil: Pernambuco State, Bonito Municipality, Stream (Igarapé) das Orquídeas , 08°31’01.1”S; 35°43’36.2” W, 741 m a.s.l.

Type material. Holotype (male): “ BRAZIL: Pernambuco State, Bonito. / Igarapé (stream) das orquídeas; 741 m. a.s.l. / 08°31’01.1”S; 35°43’36.2” W; 3/v/2014. / N. Hamada, J. M. Nascimento & J. O. Silva, leg. // ♂ // HOLO- TYPUS [red label] // Hydraena (Hydraenopsis) pernambucana sp. n. ” (genitalia extracted and mounted on same card) ( INPA).

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

Description. Habitus as in Fig. 6 . Size: Holotype: Male BL 1.38 mm; EL 0.84 mm; EW 0.60 mm.

Color ( Fig. 6 ): Dorsum of head dark, labrum dark brown; pronotum with disc dark brown and lateral sides yellowish brown, especially in anterior angles; elytra dark brown, lateral margins and apex yellowish brown. Antennae and maxillary palps testaceous, apex of last palpomere yellowish; legs brown, tibiae testaceous. Ventral surface and epipleura dark brown.

Head: Labrum micropunctured, with an open v-shaped apicomedian emargination, external margins of lobes convex. Clypeus with small punctures very sparsely arranged and with only a few, small white setae. Punctures on frons slightly smaller and sparse on median area, interstices between punctures smooth and shiny.

Pronotum: Wider than long, maximum width at the middle length. Anterior margin weakly emarginate behind frons, with disc shiny and punctate. Scintilla absent. Sides weakly convex with margins serrate. Posterior margin slightly convex. Punctures on disc much larger and deeper than those on frons, interstices wide and shiny. Disc with a flat median area. PF1 absent, PF3 broad and shallow deep, PF2 shallow deep, PF4 absent.

Elytra: Arcuate laterally, short and wide, with marked shoulders. Lateral explanate margins moderate, wider in the elytra apical half, absent on apex. With 8 rows of regular impressed punctures between suture and shoulder; size of punctures similar to those of the pronotum or slightly larger. Intervals not raised, shiny. Apex rounded with a small sutural echancrure.

Mesoventrite: With a wide straight short carina.

Metaventrite: Plaques sparsely marked, at sides of a deep median area, densely punctured.

Legs: Protibia slightly expanded towards apex. Mesotibia and metatibia straight and slender.

Abdomen: Apex symmetrical.

Aedeagus: As in Fig. 7 . Phallobase symmetrical in ventral view ( Fig. 7A ) and wide in lateral view ( Fig. 7B ). Main piece geniculate in lateral view, with a distinct, apical, long curled flagellum. Parameres long, moderately slender and starting at basal sides of main piece. Left paramere distally enlarged in lateral view.

Female: Not yet known.

Differential diagnosis. The new species is a member of the s teineri complex in the marginicollis group, sensu Perkins (2011), which includes two medium-sized species, without pronotal scintilla and aedeagi with main piece distally enlarged, parameres attached at basal half of main piece and a long flexible flagellum. Hydraena pernambucana sp. n. is close to H. steineri Perkins, 2011 (see Perkins 2011, fig. 120), but it differs mainly in the aedeagus morphology, having a geniculate main piece in lateral view and a distal lobe with a projected acute dorsal area ( Fig. 7 ).

Distribution. Currently known from the type locality (Bonito, Pernambuco State), northeast Brazil, near Atlantic coast ( Fig. 8 ).

Etymology. This species is named after the State of Pernambuco in Brazil, where the type locality is located. The name is in apposition in the adjective case.

Habitat. The type material was collected in a stream at 741 m a.s.l., located in a semideciduous seasonal forest in the Atlantic Forest biome. The measured water pH was 8.0 and conductivity was 57.3 µS/cm.

Figures

FIGURE 6. Dorsal habitus of Hydraena pernambucana sp. n., holotype male. Scale bar = 0.5 mm.

FIGURE 7. Hydraena pernambucana sp. n., holotype male. Aedeagus in (A) ventral and (B) lateral view. Scale ba r= 0.1 mm.

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