Scarabaeus typhon has the extensively wide distribution from Europe to the Far East Asia and the extremely similar morphological feature with closely related species. The Korean population of S. typhon had often been confused in its specific status including several misidentifications and synonymous name. By these circumstances, we presumed that there is a possibility to exist potential cryptic species or subspecies, which might be separated between local populations across their distribution range. Therefore, the primary aim of this study was to reassess that the geographical populations of S. typhon can be divided into each other and to establish a sketchy knowledge of its unknown phylogenetic relationships between the relatives using COI gene and comparative morphology. As the result, S. typhon was detected as a single species despite to have the wide distribution and the various intraspecific distances ranging from 0.67% to 3.50%. Two species, S. pius and S. babori were revealed to have two distinct lineages respectively. Among them, two Korean female specimens were detected belonging to group B of S. pius, it is suggested as a cryptic species or subspecies.

In traditional taxonomy on the family Cantharidae, color pattern of the body and the structure of the male genitalia have been often used as diagnostic characters in identification of the specific level. However, these characters caused the difficulty in identifying the female in case a species was described only by male specimens or has the several color types among individuals. In this study, we attempted to evaluate the species reality of Asiopodabrus fragiliformis which was often difficult to be identified due to individual variation in color pattern and lack of information of female, through searching for new morphological diagnostic characters as well as DNA barcoding analysis, including their closely relative species from Russia and Japan. The results showed that A. fragiliformis was represented as three clusters strongly supported by high value of boots trap (>99%) and over 3% branch length. The pairwise distances between species of Asiopodabrus were detected larger, ranged from 3.4–9.5%, than the intragroup distance ranged from 0–2.9% indicating presence of a barcoding gap. And then, the three clusters were respectively determined as A. fragiliformis, A. kurvatovi and a new species through the analysis of morphology and COI gene. Therefore, we suggest that the species delineation on polymorphic species and the female specimens of closely resembling species would be more exactly and effectively determined if DNA barcoding and the traditional taxonomy are used as complementary methods for identification.