Oncopsis planiscuta Thomson 1870

9. Oncopsis planiscuta (Thomson, 1870)

Figs. 95–100, 112–115

O. sardescens Anufriev, 1967 (Anufriev, 1977: 15)

Description. Coloration typical, females similar to males or somewhat lighter.

Penis with ventral margin convex in side view and with side margins uneven or serrated in ventral view (Figs. 95–96). Lower appendage of dorsal connective bifurcated, with branches of equal length, diverging, parallel, or bent inwards (Figs. 96–98). Style more or less expanded in distal half, with wedge-shaped tip (Figs. 99–100).

Body length (including tegmina): ♂, 4.0– 4.7 mm; ♀, 4.5–5.0 mm.

Differs from all other species by shape of lower appendage of dorsal connective. Only species feeding on Duschekia.

Host. Duschekia fruticosa and D. maximowiczii.

Distribution. Northern Europe (Ossiannilsson, 1981); Russia: Northern part of European Russia, Siberia, the Russian Far East including Sakhalin and Kurile Islands; Japan: Honshu (as O. sardescens Anufriev, 1967; Hayashi & Higashikawa, 1997).

Remarks. O. sardescens was described from the Russian Far East (Anufriev, 1967); two years later it was lowered in rank to a subspecies of O. planiscuta (Lauterer & Anufriev, 1969). In Anufriev (1977) it appeared as a junior synonym of O. planiscuta for the first time, but without formal establishment of a synonymy (the note “syn. n.” after the species name, any explanations, etc.). The search in “Zoological Record” database returned no results concerning synonymy of these two species.

In males from the Southern Sakhalin (environs of Sokol Town, from D. maximowiczii, recording at 22–23o C) signals are unceasing trains of syllables lasting for 10-20 s (Fig. 112). Calling signals of the only studied male from Siberia (environs of Nizhneudinsk, ca. 300 km West of Irkutsk, from D. fruticosa, recording at 27o C) consist of short trains of syllables separated by pauses (Fig. 113). However, syllable shape and repetition period in signals of males from both localities are similar (Figs. 114–115); this supports the synonymy of O. planiscuta and O. sardescens.