Euura ribesii

268 Euura ribesii group Black or dark brown pterostigma, short valvula 3, and structure of lancet and penis valve enables recognition of the group among the other Euura. Of the species of Euura with a black pterostigma, only E. spiraeae has a similar type of lancet as in the E. ribesii group. In E. spiraeae, the setae of the lancet are hair-like and the basalmost annulus is narrower (compared to height) than in the E. ribesii group (setae spine-like). Only E. vastatrix, a rare species in Eastern Europe, seems to have a pale pterostigma, in which case the spine-like setae of the lancet can be used to distinguish the females from the species with a similar type of lancet (papillosa group, and E. hypoxantha and E. jugicola of the myosotidis group). Euura ribesii group females lay eggs on the undersides of leaves (Viitasaari 1980), in contrast to most other Euura that lay eggs inside the leaf or petiole tissue. This habit of egg-laying is shared with E. spiraeae (Robbins 1927; Hara et al. 2022) and the papillosa group (Urban 2001) with a similar type of lancet. Euura hypoxantha and E. jugicola (myosotidis group) also have a similar type of lancet, but egg laying habits of these species are not known. Seven species are recognized. Most common are E. ribesii and E. leucotrocha, in Central and Western Europe also E. similator. The other species are rarely encountered.