The warming climate will extend the distribution and increase herbivorous insects because temperature limits the ranges of most insect species and has a direct effect on insect development. The ability of trees to adapt to new herbivory pressure requires genetic variation in resistance within and between tree populations as well as phenotypic plasticity. We micropropagated 26 silver birch genotypes originating from six provenances (60°–67°N) in Finland. The genotypes were planted at common gardens, located in southern, central and northern Finland. There were overall differences between the provenances in their susceptibility to herbivores showing increasing trend towards higher latitude provenances. There was a significant interaction between common garden site and provenance. There were no significant differences between the genotypes within each provenance. Our results suggest that most of the genetic variation in resistance is found between populations. High latitude seedlings are less resistant to herbivores than low latitude. Different provenances are preferred at different environments. The non-significant differences among genotypes within provenances in their intensity of leaf damage suggest high individual variation in resistance within a tree population.