Inferring distributional shifts of epidemiologically important North and Central American sandflies from Pleistocene to future scenarios

Abstract

Nine sandfly species (Diptera: Psychodidae) are suspected or proven vectors of Leishmania spp. in the North and Central America region. The ecological niches for these nine species were modelled in three time periods and the overlaps for all time periods of the geographic predictions (G space), and of ecological dimensions using pairwise comparisons of equivalent niches (E space), were calculated. Two Nearctic, six Neotropical and one species in both bioregions occupied a reduced number of distribution areas. The ecological niche projections for most sandfly species other than Lutzomyia shannoni and Lutzomyia ovallesi have not expanded significantly since the Pleistocene. Only three species increase significantly to 2050, whereas all others remain stable. Lutzomyia longipalpis shared a similar ecological niche with more species than any other, although both L. longipalpis and Lutzomyia olmeca olmeca had conserved distributions over time. Climate change, at both regional and local levels, will play a significant role in the temporal and spatial distributions of sandfly species.

Genetic diversity, phylogeography and molecular clock of the Lutzomyia longipalpis complex (Diptera: Psychodidae)

“…Secondary divergence between the Col2 and the Ven haplogroups (0.25 MYA) and between Ar2 and Ar-Bra/Ar1 haplogroups (0.22 MYA), occurred on similar time scales. Diversification of all haplogroups occurred after the middle Pleistocene, probably during inter-glacial periods, when landscape fragmentation probably provoked diversification hotspots which conserved high diversity [ 13 ]. Extreme climate changes that occurred in the Pleistocene forced adaptation/selection of most biota, including phlebotomine sandflies, to resulting biotic and abiotic conditions [ 94 ].…”

“…Extreme climate changes that occurred in the Pleistocene forced adaptation/selection of most biota, including phlebotomine sandflies, to resulting biotic and abiotic conditions [ 94 ]. Sandflies may have been subjected to local cycles of dry and cold periods, taking refuge and adapting to the more permanent humid resting fragments, which allowed these haplogroups and diversity to evolve [ 13 , 95 ]. Indeed, plant species’ distribution shifts resulting from climate variation during the Pleistocene, have also been associated with changes in Lu .…”

“…However, recent analyses indicate a highly conserved geographic coverage of the ecological niche of Lu . longipalpis from the Last Glacial Maximum (LGM) in northern Mesoamerica (88.1%), the species complex´ northern limit [ 13 ]. Hence, genetic diversity is highest in the most temporally conserved landscapes.…”

“…Recent studies using ecological niche models report that anticipated distributional shifts of Lu . longipalpis vary by region, although greater projected landscape fragmentation and anthropic modifications will not significantly affect model projections [ 12 , 13 ]. This sandfly is adapted to a variety of habitats in tropical regions, from rocky, arid, semi-arid, to very humid, and forested [ 11 , 14 ].…”

Diversity and potential distribution of culicids of medical importance of the Yucatan Peninsula, Mexico

“…18 The parameters for MaxEnt required use of bootstrap procedures for the replicate run type, maximum interactions (N=500), features, regularization multiplier (N=2), max number of background points (N=10 000), bootstrap (N=10) and do clamping. 21,22 All models were converted into binary (absence/ presence) maps based on 95% of occurrence points 23 in order to create a map of the richness of species of medical importance in the region. 18 Models were evaluated using the partial-Receiver Operating Characteristic (partial-ROC) software, and a ratio was calculated.…”