Exotic bees in urban ecosystems: establishment, impact, and potential for invasion

Native bee species decline has sparked extensive research and conservation efforts, particularly in urban areas where initiatives and interventions aim to restore native bee populations. Paradoxically, these same urban interventions may inadvertently support non-native bee species, fostering the establishment of thriving exotic populations. Exotic bees often thrive in urban environments where advantageous traits, such as cavity-nesting and high reproductive plasticity, combine with human activities that intentionally and unintentionally facilitate their introduction and spread. Although many exotic species remain benign, others may transition to invasive status, leading to competition with native bees, the spread of diseases, and interference in biodiversity assessments. This review synthesizes current knowledge on how urbanization impacts exotic bee establishment and assesses potential pathways for these species to become invasive.