Carlos Eduardo Almeida

Background: A new triatomine species was discovered in the semiarid Caatinga region of Rio Grande do Norte, Brazil, where it coexists with Triatoma brasiliensis in both natural and artificial habitats. Methods: Triatomine specimens were captured in peridomestic and sylvatic environments in Rio Grande do Norte. Their identification was based on a combination of analyses, including morphology using dichotomous keys, head and hemelytron morphometry, and phylogeny using cytochrome b and internal transcribed spacer markers. Results: The new species exhibits morphological traits that are intermediate between those of Triatoma brasiliensis and Triatoma petrocchiae , but has distinct characteristics, leading to its designation as Triatoma chiarii sp. nov. Geometric morphometric analysis of its wings and head clearly distinguished T. chiarii sp. nov. from T. brasiliensis and T. petrocchiae , while phylogenetic reconstruction confirmed its placement within the T. brasiliensis species complex. Both approaches consistently supported T. chiarii sp. nov. as a species closely related to T. petrocchiae , but with sufficient phenotypic and genotypic divergence to warrant its recognition as a new taxonomic entity. Conclusions: Since T. chiarii sp. nov. was also found in the peridomestic environment, its possible role in the eco-epidemiology of Chagas disease warrants further investigation.

Este estudo analisa a dinâmica ecológica da doença de Chagas e os fatores socioambientais envolvidos na sua transmissão, compreendendo como a degradação ambiental influencia na dispersão desses vetores, e destacando a importância da conservação de ecossistemas naturais para minimizar a interação entre os vetores e as populações humanas, contribuindo para o desenvolvimento de políticas públicas sustentáveis. Por meio de uma abordagem qualitativa, fundamentada em revisão bibliográfica e análise de dados epidemiológicos entre 2000 e 2024, os autores investigaram como a degradação ambiental, as condições socioeconômicas e a interação entre vetores, hospedeiros e seres humanos impactam a incidência da doença. Os resultados revelam que o desmatamento (n = 7), a fragmentação de habitats (n = 6) e a precariedade das habitações (n = 9) favorecem a dispersão de triatomíneos para áreas domiciliares, ampliando o risco de infecção por Trypanosoma cruzi. A espécie Triatoma petrocchiae, pertencente ao complexo Triatoma brasiliensis, é abordada com ênfase por sua relevância epidemiológica e distribuição simpátrica com outros vetores no semiárido nordestino. Diante desse cenário, o estudo propõe estratégias integradas de controle baseadas na conservação ambiental, melhorias habitacionais, práticas agrícolas sustentáveis e educação ambiental com participação comunitária. Conclui-se que abordagens que integrem saúde pública e ecologia são essenciais para o enfrentamento eficaz e sustentável da doença de Chagas, especialmente em regiões vulneráveis, promovendo justiça socioambiental e prevenção a longo prazo.

Background: Triatoma brasiliensis brasiliensis is the primary vector of Chagas disease in Brazil's semi-arid regions, exhibiting adaptability to various environments, including domestic and peridomestic. Despite its significance, comprehensive genomic data for this subspecies remain limited. Methods: We assembled the complete mitochondrial genome of T. b. brasiliensis using a combination of Illumina and Sanger sequencing technologies, the latter being necessary to obtain the control region with eight primers designed in this study. The mitogenome was annotated to identify gene content and organization. Phylogenetic relationships were inferred using conserved blocks of 13 protein-coding genes and 22 transfer RNA genes. For this analysis, 18 representative triatomines with near-complete mitogenomes were selected, and phylogenetic reconstruction was performed using the maximum ikelihood method. Results: The complete mitogenome spans 16,575 base pairs and includes 13 protein-coding genes, 22 transfer RNA genes, and two ribosomal RNA genes, consistent with the typical structure of insect mitochondrial genomes. The control region exhibited tandem and inverted repeats arranged in blocks, as observed for other Reduviidae. Given the limited availability of mitogenomes, our phylogenetic analysis provided statistical support for T. b. brasiliensis as a sister taxon to Triatoma infestans, forming a well-supported clade that is sister to Triatoma vitticeps. Conclusions: The availability of this mitogenome provides insights into the systematics, biology, and genomics of triatomine species while also enhancing our understanding of their evolutionary relationships. However, the limited number of available mitogenomes, particularly for South American Triatoma species, underscores the need for further sequencing efforts to improve phylogenetic resolution and support comparative genomic studies. Graphical

Chagas disease (CD) is a neglected illness affecting approximately seven million individuals, with vector transmission occurring via triatomine bugs. The Rhodniini tribe comprises 24 species, grouped into the Rhodnius and Psammolestes genera. Given the importance of accurately identifying CD vectors, the taxonomy of Psammolestes spp. was revisited using morphological and morphometric data. Specimens of P. tertius, P. coreodes, and P. arthuri were collected, and the morphological characteristics of the head, thorax, abdomen, and eggs were analyzed. Morphometric studies of eggs were also conducted. Dichotomous keys allowing for the differentiation of Psammolestes spp. were elaborated based on adult insect and egg morphological characteristics. Through these studies, it was possible to differentiate the three Psammolestes species and confirm that this genus should not be classified under the Rhodnius genus, contributing to Rhodniini taxonomy.