Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/2/2013
Publication Date: 4/1/2014
Citation: Fuentes-Contreras, E., Basoalto, E., Franck, P., Lavandero, B., Knight, A.L., Ramirez, C.C. 2014. Measuring local genetic variability in populations of codling moth (Lepidoptera: Tortricidae) across an unmanaged / commercial orchard interface. Environmental Entomology. 43(2):520-527; DOI: http://dx.doi.org/10.1603/EN13131. Interpretive Summary: Management of codling moth in commercial apple orchards can be strongly impacted by the dispersal of moths from unmanaged outside hosts. This interplay of moths across this boundary can influence both the selection for insecticide resistance and the efficacy of sex pheromones for mating disruption within the orchard. Studies conducted by researchers at the University of Talca in Chile with collaboration with scientists at the USDA, ARS, Yakima Agricultural Research Laboratory, Wapato, WA and INRA in Avignon, France have measured the degree of genetic exchange occurring across this interface in a typical agricultural environment in central Chile. These data highlight the importance of using an area wide management program to control codling moth within a diverse landscape.
Technical Abstract: The genetic structure of adult codling moth Cydia pomonella L., populations was characterized both inside a managed apple, Malus domestica Borkdhausen, orchard and in surrounding unmanaged hosts and non-host trees in central Chile during 2006-2007. Adult males were collected using an array of sex pheromone-baited traps. Five microsatellite genetic markers were used to study the population genetic structure across both spatial (1-100 ha) and temporal (generations within a season) gradients. Analysis of molecular variance (AMOVA) found a significant, but weak association in both the spatial and temporal genetic structures. Discriminant analysis also found significant differentiation between the first and second generation for traps located either inside or outside the managed orchard. The Bayesian assignment test detected three genetic clusters during each of the two generations, which corresponded to different areas within the unmanaged / managed apple orchard interface. The lack of a strong spatial structure at a local scale was hypothesized to be due to active adult movement between the managed and unmanaged hosts and the asymmetry in the insecticide selection pressure inside and outside the managed habitats. These data highlight the importance of developing area-wide management programs that incorporate management tactics effective at the landscape level for successful codling moth control.