Euura longiserra

235 Euura longiserra group Although the group is not monophyletic based on nuclear genes (E. abnormis, E. longicauda, and a North American species form a separate clade from the others), it is well supported by morphology (long valvula 3 and lancet usually with papilliform serrulae, malar space about 1.5–2.5 times as long as diameter of front ocellus) and in most part also based on mitochondrial COI. While nearly all sampled (Palaearctic) specimens of the longiserra group form a strongly supported clade based on COI, two females from California (2300–2600 m a.s.l.), USA, group with Euura brunnea. Morphologically, these females from California do not seem to be distinguishable from those of E. neglecta, but the nuclear genes of one specimen group it with E. abnormis and E. longicauda. Because the current nuclear data do not strongly contradict the monophyly of the longiserra group, it seems possible that sequencing of additional genes could reveal stronger support. The ambiguous lack of support based on genetic data may be due to incomplete lineage sorting and historical introgressions.