A test of multiple climate-based hypotheses for distribution limits of the Andean darkling beetles (Coleoptera: Tenebrionidae)

CARRARA R.; PERI P.L.; FLORES G.E.

Mendoza

Simposio; Fourth International Tenebrionoidea Symposium; 2015

CONICET

Several hypotheses related climatic variables as limiting factors of insectdistribution ranges: the ?energy?availability hypothesis? posits that are high and low temperatures, the ?water?availability hypothesis?, posits that is low precipitation and both ?energy?variability hypothesis? and ?water?variability hypothesis? posits that is high seasonal variation in temperature and precipitation, respectively. In this work we use occurrence data of 23 endemic tenebrionids from the Andean region to assess to what extent the diffrent climatic variables limit their distribution ranges. First, we utilize maximum entropy modeling to evaluate the fi to data of 14 candidate models, whichresulting from the combination of diffrent hypotheses, by applying Akaike Information Criterion (AIC). Then, from best fitng model to each species we conduct analyses between species probabilities of occurrence and climatic variables to recognize its role as limiting factors of species distributions. Results demonstrated that species distributions, as a whole, are bettr explained by the action of more than one climatic variable, with the exception of one species. From 23 species only 10 showed that climate act as limiting factor of their distribution ranges. Among climatic variables those representing water variability were identifid as the most inflential for species distribution ranges, followed by water availability, energy availability and energy variability. Considering hypotheses formulations, only relationships between water availability and distribution ranges responded according to expectations by limiting species distribution toward low precipitations; instead, the remaining relationships responded contrary to expectations limiting species distributions toward low energy availability, and water and energy variability. This result suggests that, far of generalities, diffrent climatic variables canact as limiting factor of species distribution ranges probably due to the evolutionary history of each species.