Molecular and Behavioral Differentiation among Brazilian Populations of Lutzomyia longipalpis (Diptera: Psychodidae: Phlebotominae)

Abstract

Background Lutzomyia longipalpis is the primary vector of American visceral leishmaniasis. There is strong evidence that L. longipalpis is a species complex, but until recently the existence of sibling species among Brazilian populations was considered a controversial issue. In addition, there is still no consensus regarding the number of species occurring in this complex.Methodology/Principal FindingsUsing period, a gene that controls circadian rhythms and affects interpulse interval periodicity of the male courtship songs in Drosophila melanogaster and close relatives, we analyzed the molecular polymorphism in a number of L. longipalpis samples from different regions in Brazil and compared the results with our previously published data using the same marker. We also studied the male copulation songs and pheromones from some of these populations. The results obtained so far suggest the existence of two main groups of populations in Brazil, one group representing a single species with males producing Burst-type copulation songs and cembrene-1 pheromones; and a second group that is more heterogeneous and probably represents a number of incipient species producing different combinations of Pulse-type songs and pheromones.Conclusions/SignificanceOur results reveal a high level of complexity in the divergence and gene-flow among Brazilian populations of the L. longipalpis species complex. This raises important questions concerning the epidemiological consequences of this incipient speciation process.

Genetic differentiation in natural populations of Lutzomyia longipalpis (Lutz & Neiva) (Diptera: Psychodidae) with different phenotypic spot patterns on tergites in males

“…Other variations in populations of L. longipalpis from Central and South America have been reported, such as behavioral, morphological and biochemical characteristics (Dias et al 1998, Lampo et al 1999, Araki et al 2009, and the existence of reproductive isolation among populations from Central and South America mediated by different sex pheromones has been already suggested (Ward et al 1988).…”

“…Studies supporting the hypothesis of the existence of a complex of species have been conducted using different methods to evaluate different populations of L. longipalpis, such as analysis of hybridization (Ward et al 1983), sex pheromones (Ward et al 1988, Hamilton et al 1996, isoenzyme pro ile analysis (Lanzaro et al 1993, Arrivillaga et al 2000, cytogenetic characters (Yin et al 1999), male copulation songs (Sousa et al 2002, Araki et al 2009, analysis of mitochondrial DNA (Arrivillaga et al 2003) and microsatellite markers (Maingon et al 2003, Watts et al 2005.…”

“…Hamilton et al (2005) reported no correlation between morphology of the abdominal spots and the type of pheromone produced. On the other hand, recent molecular data associated with the analysis of male copulation songs and pheromones of L. longipalpis from different regions of Brazil suggest the existence of two main groups of populations (Araki et al 2009). The irst group represents a single species with males producing Burst-type copulation songs and cembrene-1 as pheromone, while the second group is more heterogeneous and probably represents a number of incipient species producing different combinations of songs and pheromones, demonstrating a high level of divergence and gene-low complexity among populations of L. longipalpis in Brazil (Araki et al 2009).…”

The dispersion of Lutzomyia longipalpis in urban areas

“…Lutzomyia longipalpis is found from southern Mexico (20°N) to Argentina (27°S), with several indications that this sandfl y might encompass a species complex 6 Mark-release-recapture experiments in urban areas of the same city 9 have shown that the maximal dispersion distance for adult sandfl ies is 243m. However, the same type of experiments conducted in the rural communities of Marajó, Pará showed a maximal dispersion distance of 700m 10 .…”

Should reproductively isolated populations of Lutzomyia longipalpis sensu lato receive taxonomically valid names?

“…longipalpis populations was published after the meeting by Araki et al (2009). These authors performed a combined analysis of different characters (molecular polymorphism of selected genes, copulation song patterns and pheromone types) and confirmed the occurrence of sympatric sibling species in new localities.…”