Taxonomy has been said facing a crisis called taxonomic impediment. This impediment is due to the bias between the vast number of species and lack of taxonomic expertise, for which reasons only a fraction of species have been formally described. Using traditional methods in the midst of biodiversity crisis, the current pace in descriptions of species is far too slow. Of taxonomic categories, species has a special status virtually in all biological research. Species also have a crucial role in many areas of society and applications, including health care, nature conservation, food industry, agriculture, legislation, forensics, assessments of environmental impacts and so on. Most biologists agree that species are true entities of nature, although their identification and objective delimitation is often extremely challenging. Our research group focuses on issues in species identification and species delimitation as well as phylogenetics (resolving evolutionary relationships between taxa) using state-of-the-art molecular techniques, including next-generation sequencing (NGS) technologies. Furthermore, our research group leads DNA barcoding activities in Finland. We use Lepidoptera (butterflies and moths) and sawflies as primary model groups, but also study many other arthropods. We believe that the emergent NGS tools and genome-wide data have a potential to resolve the long-standing issues of systematics, such as objective delimitation of allopatric (geographically isolated) populations into species and in revealing cryptic diversity.