Using eco-physiological traits to understand the realized niche the role of desiccation tolerance in Chagas disease vectors

• Published in: Oecologia Vol. 185; no. 4; pp. 607 - 618
• Main Authors: de la Vega, Gerardo J., Schilman, Pablo E.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Science + Business Media 01-12-2017; Springer Berlin Heidelberg; Springer; Springer Nature B.V
• Subjects: Analysis; Arid environments; Arid regions; Arid zones; Biomedical and Life Sciences; Chagas disease; Climate change; Dehydration; Desiccants; Desiccation; Diseases; Distribution; Ecology; Hydrology/Water Resources; Insects; Life Sciences; Moisture content; Niches; Permeability; Physiological aspects; PHYSIOLOGICAL ECOLOGY - ORIGINAL RESEARCH; Physiology; Plant Sciences; Ratios; Species; Trypanosoma cruzi; Vapor pressure; Vapour pressure; Vector-borne diseases; Vectors; Vectors (Biology); Water content; Water vapor; Water vapour; Chagas disease vectors; Physiological ecology; Desiccation tolerance; SDM
• ISSN: 0029-8549; 1432-1939
• DOI: 10.1007/s00442-017-3986-1

Small ectotherms, such as insects, with high surface area-to-volume ratios are usually at risk of dehydration in arid environments. We hypothesize that desiccation tolerance in insects could be reflected in their distribution, which is limited by areas with high relative values of water vapor pressure deficit (VPD) (e.g., hot and dry). The main goal of this study was to explore whether incorporation of eco-physiological traits such as desiccation tolerance in arid environments can improve our understanding of species distribution models (SDM). We use a novel eco-physiological approach to understand the distribution and the potential overlap with their fundamental niche in triatomine bugs, Chagas disease vectors. The desiccation dimension for T. infestans, T. delpontei, T. dimidiata, and T. sordida niches seems to extend to very dry areas. For T. vitticeps, xeric areas seem to limit the geographical range of their realized niche. The maximum VPD limits the western and southern distributions of T. vitticeps, T. delpontei, and T. patagonica. All species showed high tolerance to desiccation with survival times (35 °C-RH -15%) ranging from 24 to 38 days, except for T. dimidiata (9 days), which can be explained by a higher water-loss rate, due to a higher cuticular permeability along with a higher critical water content. This approach indicates that most of these triatomine bugs could be exploiting the dryness dimension of their fundamental niche. Incorporating such species-specific traits in studies of distribution, range, and limits under scenarios of changing climate could enhance predictions of movement of diseasecausing vectors into novel regions.