Discovery of Eliozeta helluo Fabricius (Diptera: Tachinidae: Phasiinae) in Korea, Japan and Mongolia with discussion of its systematic status based on morphology and DNA barcoding

Abstract The genus Eliozeta Rondani, 1856 of the tribe Gymnosomatini includes two species that exhibit high intraspecific variability. One of these species, E. helluo (Fabricius, 1805), is reported here for the first time from Korea, Japan and Mongolia. Diagnoses and description are provided based on the examination of obtained specimens. Our study of E. helluo included 46 freshly frozen individuals having variable abdominal patterns and showing sexual dimorphism, allowing us to examine intraspecific variability and species status. We examined the morphological variations and analyzed the DNA barcode sequences of individuals, covering as many morphological variants as possible, to permit inferences about the number of biological species represented. A DNA barcoding analysis of six Korean plus two Mongolian E. helluo sequences and 112 gymnosomatine sequences retrieved from the Barcode of Life Data (BOLD) Systems revealed that E. helluo is a widely distributed and highly variable species. Furthermore, we discovered that the barcode sequences currently listed as E. helluo in BOLD Systems formed three distinct lineages within a single strong monophyletic clade. Although further study is needed, we believe that our samples plus most European samples represent the true E. helluo, but the other two lineages (Bulgarian and Middle Eastern samples) probably represent closely related and morphologically similar Eliozeta species. Our findings are also consistent with those of two previously published molecular studies on Eliozeta, in the non-monophyly of this genus.