Platystethynium (Platystethynium) Ogloblin 1946

Key to species of Platystethynium (subgenus Platystethynium) in the Old World, females 1 Head in dorsal view at least as long as wide; body strongly flattened (onomarchicidum species group); F3 without mps .................................................................................................... 2 – Head in dorsal view wider than long; body at most a little flattened (Figure 4 (a)) (triclavatum species group) (Europe); F3 with mps ...................................................................... ................................................. P. (Platystethynium) triclavatum (Donev and Huber 2002) 2(1) F5 much larger than F6 (Triapitsyn 2018, p. 161, fig. 105); macropterous (Figure 4 (a)); ovipositor at least about 1.8 times length of metatibia and notably exserted beyond apex of gaster (Oriental region) ........................................................................................................... ........................................................... P. (Platystethynium) onomarchicidum Ogloblin 1946 F5 almost as large as F6 (Figure 2 (b)); apterous (Figures 2 (c) and 3(a–c)); ovipositor (Figure 1 (b)) about 0.9 times length of metatibia and not exserted beyond apex of gaster (Europe) .............................................. P. (Platystethynium) apteron Triapitsyn, sp. n.