POPULATION GENETIC STRUCTURE OF THE CODLING MOTH IN THE SOUTHERN CONE OF SOUTH AMERICA: IMPLICATIONS FOR AREA WIDE MANAGEMENT PROGRAMS

CICHON LILIANA; SOLEÑO JIMENA; BASOALTO E; MONTAGNA MÓNICA; FRANCK P; GUIÑAZÚ NATALIA; GARRIDO SILVINA; ANGIANO LILIANA; RODRIGUEZ MA; FUENTES-CONTRERAS EDUARDO

Viena

Workshop; "Integrated Plant Protection in Fruit Crops" Sub Groups "Pome fruit arthropods" and "Stone fruits"; 2014

International Organisation for Biological Control

The codling moth, Cydia pomonella (L.), is an invasive pest of pome fruits introduced to the Americas during the 19th century. In the southern cone of South America this pest is widespread at both sides of the Andes range separating Argentina and Chile, where the largest area of pome fruit production of the southern hemisphere is located. We performed an analysis of the population genetic variability and structure of C. pomonella in Argentina and Chile using microsatellite markers. We sampled C. pomonella from apple as the main host-plant along its distribution area (approx. 1,800 km) in both countries. Significant genetic differentiation among samples from Argentine and Chile (FSC = 0.045), and between all localities (FST = 0.085) was found. Significant isolation by distance (IBD) was found for each country and also when samples from both sides of the Andes range were pooled, although with a lower correlation coefficient. By using a Bayesian assignment test (Structure) we found different populations in the Chilean and Argentinian sides of the Andes, which suggest independent invasion events and subsequent genetic isolation between countries. In summary, our results indicate a high genetic exchange of C. pomonella within countries, but with significant genetic differentiation between countries. Our results could be explained by C. pomonella dispersal mediated by human activities related to fruit production in each country with little exchange between them, because the Andes range is a significant barrier for dispersal by flight and quarantine barriers prevent the movement of plant material or infested fruit between countries.