Acarological taxonomy plays a critical role in the protection of British plant health through the detection and identification of mites associated with plant imports, stored products and growing crops. Increasing global trade and climate-driven shifts in species distributions are intensifying the challenges faced by quarantine pest diagnostics. Simultaneously, mite identifications for diagnostic services, as well as biodiversity and ecological studies, are hindered by the continued decline in the number of specialists with expertise in mite taxonomy in Britian. Data from mite samples submitted to Fera Science’s entomology diagnostic laboratory were reviewed to assess trends in taxonomic diversity, host association and country of origin. Levels of specialist taxonomic expertise within UK biosecurity diagnostics, and more broadly across the country, were examined to determine the extent of taxonomic knowledge in Britain relating to both native and non-native fauna. Within the entomology diagnostics laboratory, which provides identifications for plant health imports inspected by the Plant Health and Seeds Inspectorate, current diagnostic workflows and proficiencies for mite identification were evaluated to identify strengths and limitations of morphological and molecular approaches in both routine and high- consequence samples. There is increasing diversity and complexity of mite interceptions associated with imported plant material in Britain, alongside growing demand for rapid and defensible identifications. However, the number of trained acarologists with taxonomic expertise working within the UK has declined, presenting potential uncertainty regarding long-term capacity to identify invasive mites in high-risk or novel interceptions. While modern molecular methods offer valuable and increasingly rapid diagnostic support, they are perpetually dependant on robust morphological taxonomy and verified reference sequences. Without strategic investment in diagnostic training and taxonomic research, the UK’s capability to detect and identify invasive mite pests are at further threat of decreasing. Strengthening educational pathways and integrating molecular methods with strong taxonomic expertise will be essential to future-proof mite biosecurity diagnostics in Britain.