Linking thermotolerances of arthropods to their niches and distributions

SCHILMAN, P.E.

Mar del Plata

Workshop; 5to Workshop Fisiología Ecológica y el Comportamiento; 2023

Temperature affects most biological processes, and therefore is one of the most important abiotic factor, especially for ectothermic animals, such as most of the arthropods. In this talk, I will present work done in the laboratory, where we showed how physiological characteristics such as thermotolerance can limit the distribution of some terrestrial arthropods species. These include everything from spiders to insect vectors of diseases and invasive species. First, on spiders of the native Atlantic forest, we tested the specialization-disturbance hypothesis, which predicts that specialist species will be more affected by disturbances than generalist ones. Our results showed a higher tolerance temperature for species living in young plantations than species living in native forest, regarless of their guild, and supporting the hypothesis. Then, I will present results showinghow the geographical distribution of seven species of triatomines, vectors of Chagas disease, can be explained, in part, by their thermo-tolerance range. Finally, physiological results from the highly invasive little fire ant, Wasmannia auropunctata, showed a modulation of the Critical thermal maximun (CTmax) and minimum (CTmin) by different acclimation temperatures and by seasonal thermal acclimatization. At local scale CTmin limited their foraging activity, and at the global scale, CTmin constitutes a key physiological trait that, when linked with the minimum temperature of the coldest month, could explain the southernmost limit of its native distribution. An eco-physiological approach help explain current distribution and predict potential spread of populations when there is no certain information about the whole distribution of the species or how they distributed under a changing environment. The latter is of great importance especially when analyzing invasive insects, pests or disease vectors.