Speciation in the Leishmania guyanensis Vector Lutzomyia umbratilis (Diptera: Psychodidae) from Northern Brazil — Implications for Epidemiology and Vector Control

This chapter starts with a brief mention of the Leishmania species and sandflies vectors that occur in the Neotropical region, especially in the Brazilian Amazon. The main focus of this chapter is a review of the taxonomic, biologic and epidemiologic studies conducted in Lutzomyia umbratilis, the main vector of Leishmania guyanensis in the northern region of Brazil. We associated these data with the population genetics studies carried out in this sandfly vector by our research team. The genetic studies were made with six samples of L. umbratilis from the central region of the Brazilian Amazon, using a large fragment (1,181 bp) of the mitochondrial DNA COI gene. Also, another study was conducted in these samples using the DNA barcode region. The results revealed rather high levels of genetic variability for all samples analyzed and a pronounced genetic differentiation between samples from both banks of the Negro and Amazon rivers. The degree of differentiation found may reflect the presence of distinct species within L. umbratilis, suggesting that the Amazon and Negro rivers may be acting as effective barriers, preventing gene flow between populations living on the two sides. These findings have important implications for epidemiology, especially regarding vector competence, which is vital information for surveillance and vector control strategies. Furthermore, this diversification process of L. umbrati‐ lis represents an interesting example for speciation studies.