A mystery solved – integrative taxonomy of Haplothrips leucanthemi and H. niger (Insecta: Thysanoptera)

Taxonomic ambiguities have been observed in many groups of organisms, i.a. in thrips (Insecta: Thysanoptera). Many species pairs belonging to this order are synonymized and recognized as separate species at the same time, depending on the adopted literature or taxonomic key. Taking into account that the biology of the most thrips species is unknown and identification based on morphological characteristics of species that are highly similar is difficult, more complex and integrative approaches are needed to define the taxonomic status of such species. In the present study, we analyzed three classes of data to resolve the relationships of two species belonging to the genus Haplothrips: H. leucanthemi (Schrank, 1781) and H. niger (Osborn, 1883), respectively. We analyzed diagnostic morphological features of larvae, molecular markers (mitochondrial COI, and nuclear 28S and ITS2), and variation in determined profiles of microbiota associated with both selected species. Only the result of the morphometric analysis was partially species-specific. Results of molecular analyses did not support the distinctiveness of H. niger in the range of species. Thus, H. leucanthemi should be rather recognized as a species complex and H. niger should be recognized as its biotype based on subtle morphological differences, as well as dissimilarities in ecological traits and reproductive mode. Parthenogenesis-inducing bacteria (i.e. Wolbachia and Rickettsia) have been identified in determined microbiota profiles of both H. leucanthemi and H. niger. Thus, further studies are needed to resolve the background of lack of males in H. niger populations.