Genetic and host-association data improve models of invasive insect distribution: An example with the South American cactus moth

Many authors have demonstrated the importance of information from species’ native ranges in advancing the understanding of invasions; however, others have shown that even with such information, invasions can remain unpredictable. These variable results suggest that there are components of species’ biology missing from such efforts. We used environmental niche modeling of a well-known escaped biological control agent, Cactoblastis cactorum (the South American cactus moth), to investigate factors that contribute towards accuracy of predictions of the moth’s current North American distribution. This particular system provides a wealth of information on biology, history of global introductions, and host associations in the native range. We recently have augmented that information with additional data on geographic distribution and population genetics within the Argentinean distribution of C. cactorum. Our work has suggested strong, genetically correlated, host association that appears to be a biotic constraint limiting the moth’s native and non-native distribution. We also see evidence of potential release from other biological constraints across the non-native distribution of C. cactorum. This research suggests particular aspects of species’ biology that could provide insight for improving our ability to predict behavior of introduced species.