DNA barcodes provide insights into the diversity and biogeography of the
non-biting midge Polypedilum (Diptera, Chironomidae) in South America.
Abstract
Aim The Neotropics, particularly South America, holds unparalleled high
levels of species richness, when compared to other major biomes. Some
neotropical areas are hotspots of a fragmentary known diversity of
insects and are under manifest danger of biodiversity loss and climate
change. Therefore, prompt estimates methods of its diversity are
urgently required to complement slower traditional taxonomic approaches.
Despite a variety of algorithms for delimiting species through
single-locus DNA barcodes having been developed and applied for rapid
estimates of species diversity in a wide array of taxa; however,
tree-based and distance-based methods may lead to different group
assignments, either overestimating or underestimating the number of
putative species. Here, we investigate the performance of different
DNA-based species delimitation approaches for a rapid biodiversity
estimate of the diversity of Polypedilum (Chironomidae, Diptera) in
South America. Location Worldwide Methods We analyze a mtDNA dataset
comprising 1,492 specimens from 598 locations worldwide. Molecular
operational taxonomic units (MOTUs) ranged from 267 to 520, based on the
Barcode Index Number (BIN), Bayesian Poisson tree processes (bPTP),
multi-rate Poisson tree processes (mPTP), single-rate Poisson tree
processes (sPTP), and generalized mixed Yule coalescent (sGMYC)
approaches. Results Our results highlight Polypedilum as a species-rich
genus, yet incompletely documented, and found the sGMYC method to be the
most adequate to estimate putative species in our dataset. Furthermore,
based on these data, we describe the distribution of diversity and some
biogeographical patterns of Polypedilum. Main Conclusions Findings imply
the genus exhibited high levels of endemism and richness of species in
the Neotropics, which confirmed our hypothesis that there are
substantial differences in community structure between the Polypedilum
fauna in South America and the neighboring regions.