On the integrative taxonomy of Trichophoromyia Barretto, 1962 and its relationship with Nyssomyia Barretto, 1962 (Diptera, Psychodidae, Phlebotominae): species delimitation, phylogeny, genus and subgenus description

Abstract

Background: The sand fly genusTrichophoromyiaBarretto, 1962 is one of the most diverse inthe subfamily Phlebotominae. The taxonomy and systematics of this group is complex due toboth a high similarity among species and unclear relationships among other sand fly groupswithin the subtribe Psychodopygina Galati, 1995. Despite their great relevance as vectors ofLeishmaniaspp., few studies have explored the usefulness of molecular markers in studyingthe diversity of this group. Methods: Here, we evaluated the use of barcode sequences of the cytochromecoxidasesubunit I gene (COI) for identifying severalTrichophoromyiaspp., by inferringintra- andinterspecific genetic distances, in addition to performing a set of several single-locus speciesdelimitation approaches using discovery methods. Moreover, weemployed a multilocusdatasetof four independent molecular markers (COI,ITS2,28SandPARA)to inferthephylogenetic species tree, estimate divergence times and delimit species under a validationmodel. Results: The phylogenetic inferencesconfirmed theparaphylyofTrichophoromyiaandNyssomyiaBarretto, 1962. Thus, two new genera, namedReburrusgen. nov. andShawmyiagen. nov., were proposed to accommodate sand flyspecies that did not fit in the aforementioned groups. Additionally, a new subgenus wasproposed:Trichophoromyia(Dilermandomyia) subg. nov., containing most speciesofTrichophoromyia. A recent speciation history was also estimated, with most of the speciesstudied diversifying during the Pleistocene. However, our dataset was insufficient to fullyresolve relationships withinTrichophoromyia(Dilermandomyia) subg. nov. Many speciesshowed paraphyletic patterns in the gene trees, and some could not be reliably identified anddelimited using bothCOIbarcodes and multilocus tools. Conclusions: The sand fly genusTrichophoromyiaexhibits a complex diversification history.Our phylogenetic inference and morphological observations ofNyssomyiaandTrichophoromyia,allowed us to propose new groups for the Psychodopygina subtribe. However, theprevalence ofspecies-level paraphyletic patterns forTrichophoromyia(Dilermandomyia) subg.nov., showed that further assessment of this group requires a broader locus sampling combined with detailed morphological analysis.