Insects are essential not only for ecosystem functioning and food security but also comprise some of the world's most destructive invasive species. Therefore, both insect declines and invasions raise major conservation concerns globally and call for respective conservation or mitigation measures. However, studies of insects are hampered by intrinsic biological features of these organisms, which include extreme population fluctuations, a huge diversity of ecological strategies, and common cryptic species. Population genetics provides a large toolkit to adequately accommodate those features, thereby enabling researchers to inform and monitor the efficacy of conservation and mitigation programs. Here, we provide an overview of the molecular and analytical methods that are relevant to insect conservation or mitigation and highlight the challenges involved in their implementation. We detail how and why temporal changes in genetic diversity, population structure and migration, and the genetic basis of adaptation should be taken into account to inform insect management programs. Finally, we review the barriers to the broad adoption of population genetics in insect research and provide guidelines to facilitate the use of these methods by stakeholders. Overall, this review provides theoretical and practical guidelines for implementing population genetics in both insect conservation and control.
