Linking thermo-tolerances of the highly invasive ant, Wasmannia auropunctata, to its current and potential distribution

CAROLINA COULIN; DE LA VEGA, GERARDO; CHIFFLET, LUCILA; CALCATERRA LUIS; SCHILMAN, PABLO

BIOLOGICAL INVASIONS

SPRINGER

Lugar: Berlin; Año: 2019

1387-3547

Species distribution models based on thecorrelation of bioclimatic variables and presencespatial data-points are useful for recognizing specieshabitat suitability. However, they have limitations inpredicting the introduced ranges of invasive speciesthat could be overcome by using species eco-physiological traits. By combining bioclimatic variableswith thermal tolerance plasticity of the highly invasivelittle fire ant, Wasmannia auropunctata, we intend tobetter understand the mechanism underlying itscurrent and future distributions. To this end, weperformed: (1) laboratory physiological experimentsto assess thermal tolerances (CTmin and CTmax) andevaluate the effect of acclimation (laboratory) andacclimatization (nature) on these variables, (2) behavioral foraging observations in the field, (3) a correlative and a simple mechanistic SDM. Briefly,physiological results showed a modulation of theCTmax and CTmin by different acclimation temperatures and by seasonal thermal acclimatization. In thefield, worker foraging activity begins at environmentaltemperatures just above (less than 1 C) the lowestCTmin recorded in the laboratory. At the global scale,CTmin constitutes a key physiological trait that, whenlinked with the minimum temperature of the coldestmonth, could explain the southernmost limit of W.auropunctata native distribution and its physiological capacity to expand in the Mediterranean region. Theeco-physiological approach carried out here may helpexplain the current distribution and predict potentialspread of populations when there is no certaininformation about the whole distribution of the speciesor under a changing environment. The latter is of greatimportance especially when analyzing invasiveinsects, pests or disease vectors