Invasive alien species (IAS) can cause a multitude of socio-economic and ecologic problems, warranting the need for their early detection, monitoring, and management. To do so, reliable species identifications are required, using morphology- and/or DNA-based approaches. BopCo is a Belgian research unit that provides such identification services for various species of policy concern, including invasive alien insects. BopCo is jointly run by the Royal Belgian Institute of Natural Sciences and the Royal Museum for Central Africa, and has access to extensive reference collections, expert taxonomists, and a comprehensive research infrastructure. BopCo handles on-demand species identification requests and is a partner on various projects related to invasive alien insects. In this framework, BopCo contributes to identifying the introduction pathways and dispersal dynamics of two invasive mosquito species in Belgium, Aedes albopictus and Ae. japonicus, as part of the MEMO+ project in collaboration with Sciensano and the Institute of Tropical Medicine. Using various DNA identification techniques, BopCo verifies the species identity of the exotic mosquitoes collected at multiple points of entry. Similarly, the Medical Component of the Belgian Armed Forces is investigating the Culicidae mosquito biodiversity at foreign deployment sites. BopCo takes part in this project by providing DNA-based identifications to support the Laboratory for Vector-Borne Diseases of the Queen Astrid Military Hospital. Accurate identification of the various mosquito species is important since they are known vectors of pathogens of significant public health concern such as Western Nile virus, Plasmodium parasites, and dengue virus. Furthermore, BopCo was involved in documenting the first occurrences of three exotic termite species in Belgium: Cryptotermes brevis, Reticulitermes banyulensis, and R. flavipes. Morphological identification of specimens was corroborated through DNA-barcoding validation. Reticulitermes flavipes is of particular concern as it has been invasive in France for many years and likely to establish populations in Belgium. Finally, BopCo evaluates the usefulness of publicly available DNA sequence data to identify the plant and animal species included in the list of Invasive Alien Species of Union Concern (EU Regulations 2016/1141 and 2017/1263). The results are presented as IAS Factsheets which aim to inform policy makers and provide relevant authorities with an identification tool for suspected IAS samples. This collection of IAS factsheets includes five factsheets on invasive alien insects.