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.