Euura Newman 1837

Genus Euura Newman, 1837 The genus is mostly defined based on genetic data. When the Euura epilosa group is excluded, the genus is strongly supported as monophyletic based on phylogenetic analyses of 10 genes (Fig. 2). Unfortunately, no clear morphological characters have been found that define the genus reliably. We provide here a key to separate Euura from the other similar Nematinae genera. Commonly observed high morphological similarity between species of Euura (sometimes even between species belonging to different groups) in combination with large within-species variability (e.g., colouration varying from mostly black to mostly pale) often makes species identification difficult without nuclear DNA. Identifications based on COI can often be even more misleading than those based on morphology, but can still in many cases be useful to identify the groups where this is difficult using morphological characters. In some cases, we do have COI sequence data for the types, but obtaining nuclear data for the old material would be much more challenging. Therefore, we have mostly relied here on sequencing of COI and nuclear DNA from a large number of fresh specimens to cover as much morphological variability as possible, in order to better match them with the available types. This does not guarantee correct identifications of all the types, meaning that some of the types might here be wrongly placed, and in the worst case a change of valid name may be required once nuclear data becomes available (which in any case might not be possible for all types).