Sand flies of Maranhão State, Brazil: checklist, distribution updates, and reported Leishmania associations

Phlebotomine sand flies are the vectors of Leishmania parasites, comprising an important component of disease ecology. In the Brazilian state of Maranhão (MA), environmental heterogeneity associated with the transition between Amazonian, Cerrado, and coastal biomes favors high species diversity, yet available information remains fragmented. This study provides an updated checklist of sand fly species recorded in MA, synthesizing published records, refining geographic distributions at the municipal level, and compiling reported Leishmania associations. A literature survey was conducted using scientific databases and reference lists of relevant publications, followed by taxonomic standardization according to current classification frameworks. Additionally, publicly available cytochrome c oxidase subunit I (COI) sequences were surveyed to evaluate genetic data availability as part of an integrative taxonomic perspective. The updated checklist documents 108 species and confirms MA as one of the most species-rich states for phlebotomine sand flies in Brazil, revealing marked spatial heterogeneity in sampling effort among municipalities. Medically important species, including Lutzomyia longipalpis and Nyssomyia whitmani , are widely distributed, supporting the persistence of visceral and cutaneous leishmaniasis transmission cycles. Reported detections of Leishmania highlight the epidemiological relevance of a limited subset of taxa , whereas most species lack parasite evidence. The survey of COI records revealed uneven genetic representation, with several taxa lacking barcode data entirely. By integrating taxonomic, geographic, epidemiological, and molecular information, this checklist provides a standardized baseline for future ecological, systematic, and surveillance studies of sand flies in Maranhão.