Parathalassius ulrichi Shamshev

Cumming, Jeffrey M., 2017, Revision of the Nearctic Parathalassius Mik (Diptera: Dolichopodidae: Parathalassiinae), with a review of the world fauna, Zootaxa 4314 (1), pp. 1-64 : 48-49

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.