Disentangle de effect of climate and human influence on distribution patterns of Scotobius pilularius Germar (Coleoptera: Tenebrionidae)

CARRARA, RODOLFO; SILVESTRO, VIOLETA A.; CHELI, GERMÁN HORACIO; FERNÁNDEZ CAMPÓN, MARÍA FLORENCIA; FLORES GUSTAVO ERNESTO

Mendoza

Simposio; Fourth International Tenebrionoidea Symposium; 2015

Scotobius pilularius Germar occurs in both natural and human modifiedareas within humid coastal and grassland environments of Argentina,Brazil and Uruguay (i.e., natural distribution area). However, inArgentina it is also found in very different environments, some ofthese climatically extreme, such as arid steppes. In these habitats, S.pilularius is found outside natural habitats and in areas associated withdifferent levels of human activity. In this work, we examine factors that may determine the observed spatial distributions of S. pilularius inits natural distribution area and recognize to what extent those factorsare responsible of its distribution in distinct habitats of Argentina.We consider that at least three hypotheses can be postulated toexplain these distributions: i) climatic conditions determine speciesoccurrences; thus, species is distributed in these habitats becauseclimate allows its subsistence; ii) there is an interplay between climaticconditions and human influence; thus, the species is distributed inareas in which climate allows its subsistence and human activitiesalso promote conditions to its subsistence; and iii) human influencedetermines its distribution; thus, human activities create conditionsto its subsistence which are independent of climatic conditions.Considering spatial information on climate, human influence anddistribution localities of S. pilularius, we assessed the support of data tothese competing hypotheses by using species distribution models. Wefound that, while within the natural distribution area of S. pilulariusthe climate and human influence hypothesis (ii) significantly explainits distribution; only the human influence hypothesis (iii) significantlyexplains its distribution in extreme habitats of Argentina. This outcomesuggests that S. pilularius probably moved from asynanthropy oran independence of human activities before human settlement, to ahemisynanthropy by inhabiting surroundings of human settlementswithin its natural areas, to conclude in eusynanthropy or a strongdependence of human activity to its subsistence outside of its naturalarea