Copper‐based antimicrobial compounds are widely used to control plant bacterial pathogens. Pathogens have adapted in response to this selective pressure. Xanthomonas citri pv. citri , a major citrus pathogen causing Asiatic citrus canker, was first reported to carry plasmid‐encoded copper resistance in Argentina. This phenotype was conferred by the cop LAB gene system. The emergence of resistant strains has since been reported...

The parthenogenetic snail Melanoides tuberculata , present in tropical fresh waters of most of the Old World before 1950, has now invaded the Neotropical area. The phylogeography of this snail was studied to evaluate the pathways and number of such invasions. Because of parthenogenetic reproduction, individuals are structured into genetical clones. Within populations from both the original and invaded areas, several morphologi...