Parathalassius ulrichi Shamshev

Parathalassius ulrichi Shamshev 1998: 4 .

Material examined. JAPAN: Hokkaido: Wakkasakanai, zone A~C, Sarobetsu, 1.vii.1967, T. Saigusa (3♂, 3♀, CNC) ; Wakkasakanai, 26.vi.1986, T. Saigusa (11♂, 3♀, ZFMK) ; Wakkanai, Sakanoshita Beach, 20.viii.1993, M. Satô (11♂, 14♀, ZFMK) .

Diagnosis. This relatively small to medium sized Palaearctic species is characterized by a head and thorax with dark setae, a subtriangular antennal postpedicel, longer lower male ommatrichia, 3 notopleural bristles (see Remarks), hyaline slightly brown-tinted wing, and dark legs with hind tarsomere 2 distinctly longer than tarsomere 3. Parathalassius ulrichi is very similar to the Nearctic P. sinclairi, but males have longer anterodorsal setae on the hind tibia, and possess thickened angled setae dorsally on the hind tarsus, rather than perpendicular peg-like setae. In addition, females of P. ulrichi have longitudinal ridges on the apex of sternite 8, unlike P. sinclairi with female sternite 8 rugose apically.

Distribution. This eastern Palaearctic species is known from the Kuril Islands (Chirinktotan, Kunashir and Shikotan) in the Russian Far East (Shamshev 1998) and is here newly recorded from Hokkaido, Japan.

Remarks. In his description of P. ulrichi Shamshev (1998) indicated that this species has 2 notopleural bristles. The specimens from Hokkaido all have 3 notopleural bristles and I. Shamshev (pers. comm.) has confirmed that additional material collected from the type locality on the Kuril Islands also have 3 (or apparently very rarely 2) notopleural bristles.