Phylogenetic relationships and evolutionary patterns of the genus Psammolestes Bergroth, 1911 (Hemiptera: Reduviidae: Triatominae)

Abstract

Background The evolutionary history of biodiversity in South America has been poorly studied in the seasonal dry tropical forest (SDTF). Species diversification in this ecosystem may have a twofold explanation. First, intermittent connections in the middle and late Pleistocene promoted species dispersal and/or genetic connectivity between lineages isolated in disjunct patches of forest. Second, allopatric speciation proceeded immediately after the formation and colonization of the SDTF in the Neogene. Here we studied the diversification of Psammolestes, a genus endemic of the SDTF and naturally infected with Trypanosoma cruzi (agent of Chagas disease), using a combination of phylogenetic, population genetics and niche model methods, and evaluated the reliability of the three morphospecies currently recognized. Results Our multilocus analyses recovered P. coreodes and P. tertius in a monophyletic clade sister to P. arthuri. Species delimitation tests recovered these lineages as different species despite the shared genetic variation observed between P. coreodes and P. tertius in five genes. Also, genetic variation of the genus clustered in three groups that were consistent with the three morphospecies. Our demographic model predicted a scenario of divergence in absence of gene flow, suggesting that mixed haplotypes may be the result of shared ancestral variation since the divergence of the subtropical-temperate species P. coreodes and P. tertius. In contrast, the tropical species P. arthuri was highly differentiated from the other two in all tests of genetic structure, and consistently, the Monmonier’s algorithm identified a clear geographical barrier that separates this species from P. coreodes and P. tertius. Conclusions We found three genetically structured lineages within Psammolestes that diverged in absence of gene flow in the late Miocene. This result supports a scenario of species formation driven by geographical isolation rather than by divergence in the face of gene flow associated with climatic oscillations in the Pleistocene. Also, we identified the Amazon basin as a climatic barrier that separates tropical from subtropical-temperate species, thus promoting allopatric speciation after long range dispersion. Finally, each species of Psammolestes occupies different climatic niches suggesting that niche conservatism is not crucial for species differentiation. These findings influence the current vector surveillance programs of Chagas disease in the region.

Exploring the Hidden World of Vectors of Chagas Disease: A Fascinating Look at the Taxonomic Aspects of the Psammolestes Genus (Hemiptera, Triatominae)

“…Recent phylogenetic studies demonstrate that Psammolestes species are phylogenetically related, with P. tertius and P. coreodes being sister species [ 25 ]. In addition, one of the models tested for species delimitation (the ‘deep divergence and large population size’ model) delimited only two species: (i) P. arthuri and (ii) P. coreodes + P. tertius [ 25 ]. However, reproductive barriers confirm the specific status of P. coreodes and P. tertius based on the biological species concept [ 44 ].…”

“…The species of the genus Psammolestes form a monophyletic group and have the same chromosomal characteristics [ 24 , 25 , 26 ]. These vectors were initially grouped into a single tribe called Psammolestini as they presented morphological distinctions when compared to Rhodnius [ 27 , 28 ].…”

Ecological Niche Modelling Approaches: Challenges and Applications in Vector-Borne Diseases

“…Similarly, the classification of the triatomine kissing bugs transmitting Chagas disease is subdued to constant changes [76,77], which sometimes are related with ecological characteristics (i.e., [78]), as well as occurs with the Lutzomyia sand flies transmitting leishmaniasis [79]. Thus, whenever possible, the databases to be used must be filtered and reinforced with a molecular identification (i.e., [69,[80][81][82]). Despite the aforementioned, the issue is usually neglected, and most of the studies rely solely on morphological identification (e.g., [83][84][85][86][87][88][89][90][91][92][93][94][95][96], but see [97] for a mixed approach), or do not even describe the identification method [70,82,[98][99][100][101][102][103][104][105][106][107][108].…”

“…Thus, whenever possible, the databases to be used must be filtered and reinforced with a molecular identification (i.e., [69,[80][81][82]). Despite the aforementioned, the issue is usually neglected, and most of the studies rely solely on morphological identification (e.g., [83][84][85][86][87][88][89][90][91][92][93][94][95][96], but see [97] for a mixed approach), or do not even describe the identification method [70,82,[98][99][100][101][102][103][104][105][106][107][108].…”

Climate and Environmental Changes and Their Potential Effects on the Dynamics of Chagas Disease: Hybridization in Rhodniini (Hemiptera, Triatominae)

“…Currently, 158 species of triatomines are known, divided into 18 genera and five tribes [45][46][47][48], with all of them considered as potential CD vectors. The tribe Rhodniini Pinto, 1926 is a monophyletic group composed of two genera: Rhodnius Stål, 1859 and Psammolestes Bergroth, 1911 [49][50][51][52]. Members of the genus Rhodnius have been grouped into three major groups: pallescens (considered as trans-Andean group, with distribution in the west of the Andes mountain range), pictipes and prolixus (considered as cis-Andean groups, with distribution in the eastern Andes and in the Amazon) [52].…”