Euura semilactea PR.

258 Euura semilactea (Zaddach, 1883) Figs 265, 475 Nematus semilacteus Zaddach, 1883 in Brischke 1883: 185. Holotype ♀, probably destroyed (Blank & Taeger 1998). Type locality: Poland, Gdansk [Danzig]. Diagnosis This is the only species in the group with a black pterostigma, but otherwise the colour pattern can be indistinguishable from E. variator. Males are also best distinguished from the others in the group by their black pterostigma. Penis valves are very similar to E. toeniata (toeniata group), which also have a black pterostigma, but have completely or mostly black underside of the abdomen and completely or nearly completely black metafemur (completely or nearly completely pale underside of abdomen and metafemur black only dorsally in E. semilactea). Host plants Salix caprea (Vikberg & Kontuniemi 1971), but also S. aurita, S. repens, S. cinerea (Enslin 1916b), and S. myrsinifolia (this study). Genetics COI Based on 3 specimens, maximum within-species distance is 4.41% and the nearest neighbours, diverging by a minimum of 0%, are Euura fasciata and E. variator. Nuclear Based on 3 specimens, maximum within-species distance is 0.51% (0.15% based on haplotypes of individual females). The nearest neighbour, diverging by a minimum of 0.37%, is Euura variator. Distribution and material examined Palaearctic. Specimens studied are from Bulgaria, Finland, Germany, Norway, Russia, and Sweden.