NMW Naturhistorisches Museum Wien Hydraena (s.str.) rukiyeae Kasapoğlu, Jäch & Skale sp. n.

Type locality: Small stream, ca. 1–2 m wide, Seki Village, 40°45'00''N, 34°25'47''E, ca. 8 km NW Iskilip, Çorum Province, north central Turkey. The stream is slightly polluted due to sewage from several villages.

Type material: Holotype (NMW): “TR: Çorum \ ca. 8 km NW Iskilip \ 20.VII.2005 \ leg. K. Erman”. Specimen dry mounted; aedeagus glued with water soluble glue to the same card. Paratypes (CKA: 2, 1, NMW: 1, 2

) same label data as holotype.

Differential Diagnosis: 1.9–2.0 mm long. Dark brown to black, head and pronotal disc often darker than pronotal margins and elytra; appendages yellowish, tips of palpi more or less distinctly darkened in most specimens.

Externally, the new species resembles H. colchica Janssens, 1963 from northeastern Turkey. It can be distinguished from the latter primarily by the narrower pronotum. In addition, males are distinguished from H. colchica by the metatibia, which is thinner and less strongly dilated in the posterior third in the new species.

Aedeagus (Fig 1): Main piece strongly curved, dorsal margin uneven; with two short setae on ventral margin in apical half and two longer ones on dorsal margin; phallobase strongly asymmetrical; distal lobe moderately long, curved, basally enlarged. Parameres with few apical setae; right paramere short, simple, moderately thick; left paramere longer and thinner, abruptly widened apically.

Female tergite X (Fig. 2): Strongly transverse; anterior margin with comparatively short trichoid setae and a few longer ones laterally; disc with trichoid setae, and very few squamose setae basally.

Gonocoxite (Fig. 3): Transverse; basal apophyses strongly projecting; base of inner plate strongly concave, projecting only laterally; cavea moderately large.

Discussion: The new species is a member of the Hydraena rufipes species group (as defined by Jäch et al. 1998). According to the genital morphology, it obviously belongs to a complex of species including H. colchica, H. fritzi Jäch, 1992, and H. janczyki Jäch, 1992 (see Jäch 1992).

Distribution: Known only from the type locality so far.

Etymology: Named for Mrs. Rukiye Kasapoǧlu, wife of the first author.