Identification key of Western Palearctic * species of Plagiognathus with predominantly pale yellow vestiture **

1. Dorsum unicolorous dark brown to black, antennal segments completely black, sometimes third and fourth segments dark brown. Vesica: cf. Schuh (2001: fig. 39). Body length: 3.3–3.6 mm (♂♂), 3.2–3.5 mm (♀♀). West Mediterranean, Balkan peninsula, Turkey .................................... P. reuterellus Schuh, 2001 (= P. flavipes Reuter, 1875, preoccupied)

– Dorsum whitish yellow to orange colored, antennal segments either unicolorous yellow or yellow with dark rings in first and second segments .................................................................................... 2

2. Corium with a faint black stripe along outer margin of endocorium, cuneus largely black, first antennal segment yellow with basal ring and pre-apical dots, second antennal segment yellow with very narrow basal ring (Fig. 2F), vesica as in Fig. 3A–C. Body length: 2.6–2.9 mm (♂♂), 2.6– 3.0 mm (♀♀). Endemic to Turkey ................................................................ P. ozgurkocaki sp. nov.

– Hemelytra and antennae unicolorous, body length 3.0– 4.2 mm ...................................................... 3

3. Membrane without a black spot, interocular distance 1.1–1.2 × as long as the eye width (Fig. 4B). Vesica: cf. Linnavuori (2010: figs 10g –h). Body length: 3.8–4.0 mm (♂♂), 3.5–3.8 mm (♀♀). Iran, Turkey .......................................................................................... P. marivanensis Linnavuori, 2010

– Membrane with a black spot, interocular distance 1.5–1.7 × as long as the eye width (Fig. 4C). Vesica cf. Schuh (2001: fig. 39). Body length: 3.1–3.4 mm (♂♂), 3.0– 3.6 mm (♀♀). Iran, Kazakhstan, Turkey ................................................................................... P. bipunctatus albicans (Reuter, 1901)

* Western Palearctic Region includes Europe, Northern Africa and South-West Asia, as defined by Vigna Taglianti et al. (1999).

** Some specimens of Plagiognathus bipunctatus albicans can have predominantly black vestiture.