Species delineation
To estimate the number of species present in the dataset, we used a molecular species delimitation method, the Poisson tree process (PTP) (Zhang, Kapli, Pavlidis, & Stamatakis, 2013), conducted on the bPTP webserver (http://species.h-its.org/ptp). We applied the same methodology as in Morek & Michalczyk (2020), constructing the tree based on concatenated COI+ITS-2 sequences in MrBayes. The results were then compared with morphological data and genetic distances, to verify the putative species identified by bPTP. In parallel to genetic delineation, we attempted to identify species using the latest diagnostic key to the genus (Morek, Gąsiorek, Stec, Blagden, & Michalczyk, 2016). Species that could not be identified are designated as “sp. nov.” followed by population code (international country code and sample number). If there were two species from the same population, an additional number/letter was added to discriminate between them. In order to aid navigation through phylogeny, all species identified and delineated in the present study are given running numbers, from #1 to #64.