CONICET | Buscador de Institutos y Recursos Humanos

Tiger moths (Arctiinae) is one of the most speciose groups among Lepidoptera, including almost 11,000 species worldwide of which at least 50% are present in the South American Neotropic region. Southern Andean Yungas and Paraná subtropical forest jointly with Chaco Serrano dry subtropical forest are three ecoregions with high insect richness. Until now, the diversity of tiger moths and their response to climatic factors and altitude in these regions were unknown. The aim of the present study was to assess the richness and composition of tiger moths in these three ecoregions and their relation with climatic variables and altitude. The adults were collected at 71 sites (21 in Yungas,19 in Paranáand 31 in Chaco Serrano) in the hot seasons from 2007 to 2013. At each sampling sites, adults were captured using a light trap at night, in new moon phase and without rain. Rarefaction and extrapolation curves jointly with a non-metric multidimensional scaling (NMDS) were performed to analyze the richness and composition of species. Also, analysis of similarities was performed to determine whether there were differences in the composition of species among areas. Altitude was registered at each sampling sites while climatic data was compiled from the Worldclim database. A permutest analysis was performed to test if species composition were related to climatic variables and altitude. Paraná showed the highest richness (125 species) followed by Yungas (63) and finally ChacoSerrano (24). Of the 180 species found, 108wereexclusive from Paraná, 38 were from Yungas and six were from Chaco Serrano. Paraná-Yungas shared10species while Paraná-Chaco Serrano and Yungas-Chaco Serrano shared three and 11species respectively. Only four species were present in all three ecoregions. NMDS showed consistent and significant differences among the three ecoregions, accordingly to their species composition. Furthermore, the variation in the composition of species among the ecoregions was mainly related with annual precipitation, precipitation seasonality, annual mean temperature and annual temperature range; and secondarily with altitude. These results highlightthat it could exist a disjunction in the composition of tiger moths among the three ecoregions. Nonetheless, within each ecoregion the variation in the composition of species was related to changes in altitude. In addition, because there are no geographical barriers among these three areas, climatic barriers must be playing an important role in tiger moths distribution, but othersfactors, such as biological interactions and vegetation changes cannot be discarded.