CONICET | Buscador de Institutos y Recursos Humanos

The South American fruit fly Anastrepha fraterculus causes significant damage to fruit and vegetable crops. An efficient integrated pest management program requires the knowledge of the adaptive strategy and population structure of the species, which are also related to its dispersion and oviposition behavior. Molecular markers represent the most valuable tool for this kind of analysis. Due to its high variability microsatellites (SSR) allow a deep analysis of population structure at fine scale. In this work we analyzed 6 SSR loci on 65 adult flies collected from 2 or 3 fruits per tree, in 9 trees of guava in an area without commercial management in Horco Molle, Tucumán, Argentina. Genetic variability was estimated by several indices. Population structure was studied with Wright´s F-statistics and analysis of molecular variance (AMOVA) considering three different hierarchical levels (trees/fruits/individuals). All analyses were performed with the packages hierfstat, poppr, ade4 and ape of the software R. Preliminary results for 4 loci showed that they were highly polymorphic with 9 to 12 alleles per locus with global Ho= 0.497 and He= 0.667. In no case evidence of pair-wise linkage disequilibrium was observed (ṝD= 0.03, P= 0.69). The results of AMOVA and F statistics were consistent and showed that the highest proportion (73.24%) of genetic variation occurs within individuals (P= 0.001) and between individuals within fruits (24.72%, P= 0.001). The remaining levels (between fruits within trees and between trees) did not show significant differences. These results suggest that there would be no fidelity in female oviposition to the same fruit and each fruit would be colonized by several females. Although still preliminary, the results suggest that ovipositing females are able to disperse significantly among trees throughout the orchard.(Póster)