Detecting Environmental Barriers to the Dispersion of the Cactus Moth through Genetic and Environmental Studies

In an international collaborative effort, a group of scientists, including Mariano Ordano, a researcher at the Instituto de Ecología Regional (IER), published a revealing study in the journal PeerJ, titled "Climatic and soil characteristics account for the genetic structure of the invasive cactus moth Cactoblastis cactorum in its native range in Argentina." This research focuses on the cactus moth *Cactoblastis cactorum*, also known as the "South American cactus moth" or "nopal moth." This invasive species has spread across Africa, Asia, Australia, the Mediterranean, the Caribbean, and North America, outside their native range in South America, threatening the biodiversity of cacti in the genus *Opuntia* and the commercial interests of the domesticated species Opuntia ficus-indica.

Using an interdisciplinary approach that combines ecological niche modeling and population genetic analyses, the study identifies key environmental barriers that may limit the expansion of this species. The results revealed a genetic structure composed of six genetic groups separated by mountainous reliefs, salt flats, and wetlands, primarily in the western region of the Gran Chaco Seco ecoregion. The ecological niche models demonstrated that the environmental adequation of this area is primarily defined by climatic and soil characteristics, such as soil temperature and moisture, soil carbon content, and precipitation variability.

This study clarifies how environmental factors can influence the genetic structure of invasive species populations in their native range, emphasizing the importance of understanding the interactions between climate, soil, and invasive species to predict their expansion potential, considering population variables in their native distribution. The research findings have applications for invasion risk modeling in other regions of the world, such as North America. With climate change rapidly altering global environmental conditions, studies like this are crucial for anticipating and mitigating threats to biodiversity and agricultural ecosystems. The research demonstrates the value of interdisciplinary approaches in ecology and landscape genetics to address complex conservation and invasive species management issues, significant contributing to our ability to protect native ecosystems and threatened species.

Andraca-Gómez G, Ordano M, Lira-Noriega A, Osorio-Olvera L, Domínguez CA, Fornoni J. 2024. Climatic and soil characteristics account for the genetic structure of the invasive cactus moth Cactoblastis cactorum, in its native range in Argentina. PeerJ 12:e16861 https://doi.org/10.7717/peerj.16861