BRIDGING THE GAP IN CHAGAS DISEASE SURVEILLANCE THROUGH THE ANALYSIS OF TRIATOMINE FAUNA AND DISTRIBUTION IN THE AMAZON-CERRADO TRANSITION ZONE.

This study provides an updated assessment of the triatomine fauna covering two major Brazilian biomes: the Amazon and the Cerrado in the state of Maranhão, Brazil, integrating data from field collections, entomological collections, and published records. The aim was to characterize species diversity, spatial distribution patterns, and new occurrence records, highlighting implications for Chagas disease surveillance. In all, 18 species belonging to six genera were recorded across 69 municipalities, revealing a high diversity of vectors. Species of the genera Rhodnius Stål, 1859 and Panstrongylus Berg, 1879 showed the widest distributions, particularly Rhodnius pictipes Stal, 1872, Rhodnius robustus Larrousse, 1927, and Panstrongylus geniculatus Latreille, 1811, demonstrating broad ecological plasticity and frequent occurrence in peri- and intradomiciliary environments. Two species were recorded for the first time in Maranhão: Rhodnius montenegrensis Rosa et al., 2012, identified in multiple sities with evidence of previous misidentification as Rhodnius robustus, and Panstrongylus rufotuberculatus Champion, 1899 both collected in an intradomiciliary setting under anthropogenic pressure. Additionally, traditionally sylvatic species occurrence in human environments reinforces the potential for vector-human contact. A regional dichotomous key for adult triatomines is also provided to support accurate species identification. These findings expand the known distribution of triatomines in Maranhão and highlight the importance of integrating field surveys, biological collections, and community-based surveillance to improve vector monitoring and support targeted strategies for Chagas disease control.