Efficient and accurate identification of potential pest organisms is fundamental to plant biosecurity. It can begin on the farm, be necessary for pre-clearance prior to shipping, be critical during border inspections, and be necessary for the management of an invasive pest  before it is established. As global trade has increased, the stakes have become higher. More trade means greater movement of cargo and commodities, together with the pests that can come with them.
With this increased risk, many countries have stepped up biosecurity requirements: markets often require certain phytosanitary standards to be met prior to shipment to help prevent the spread of potentially invasive and damaging pests (Keller et al., 2011). Most countries also perform border inspections, sometimes including pre-clearance or pre-departure inspections and/or treatments at the origin, in transit, or upon arrival.
This increase in the risk of pest introductions comes at a time when the number of taxonomists is declining (Wheeler, Q D, 2013); fewer taxonomists are being trained, particularly those able to distinguish regulated pests from similar organisms. Although many new and faster technologies have been developed to help streamline pest identification, including molecular and biochemical methods, traditional morphological identification is still the primary method used in practice. The good news is that emerging computer technologies could take morphological identification into a new era. The biosecurity challenge is how to meet an increased need for pest identification given the continuing decline in available taxonomic expertise.
Printed pest and disease brochures and leaflets, farmer field schools, training of para-taxonomists, and plant clinics – provide some answers to improving the capacity to identify pests. The focus of this review is on increasing the role that digital identification tools (DITs)  can play in meeting the need for rapid, accurate pest identification and diagnostics. There are three specific activities that these DITs can address:
- pest management in the field (including pest and natural enemy identification);
- quarantine (invasive pest identification in transport and products); and
- education and training of students and practitioners.
The information and communication technology (ICT) revolution over the past 40 years has involved hardware development, from large computers to desk top devices and smartphones, combined with a surge in software technologies, such as the Internet, Wi-Fi, and smartphone apps. This ICT advancement has provided the foundation for developing a wide range of DITs, offering alternative means for biosecurity officials, testing laboratories, and others to obtain pest identification support. For instance, IDaids, an online database of recommended DITs, described later in this review, listed over 6057 digital resources (as of April 2023).
In the following section (2) of this review, the different types of DITs that already exist are reviewed, together with the role they can play to support identification and diagnosis of pest organisms for biosecurity purposes, as well as for plant protection more generally. These tools include those providing remote connections with experts, digital identification guides, identification and diagnostic keys, image databases, and emerging artificial intelligence (AI) applications.
The next section (3) describes the ways these tools are currently being developed and used by testing laboratories, and by government and other agencies. Two case studies (one in the United States and one in Europe) indicate the strategies used to identify the need for identification tools; as well as how they are being developed in combination with other databases, images, and fact sheets, to meet the different needs of quarantine officers, testing laboratories, and other inspection activities related to trade.
Two further examples are concerned particularly with international, collaborative DIT projects. The first project concerns the development of digital tools and resources for seed identification. The second concerns an international collaborative effort by several thrips taxonomists to develop a series of identification tools for thrips, to meet the needs of specific countries and regions.
The final section (4) of this review considers the lessons we have learned about the development and use of DITs and the need for greater integration with other tools, such as lab-based molecular techniques, image databases, mapping tools, pest reporting, and online and interactive training. The review concludes with a discussion of the role of DITs in the future, including the potential of image recognition software, using AI, and the implications this could have for the role of human taxonomic and diagnostic expertise.
 [ The term “pest” is used in the sense of the broad FAO definition FAO, 2021 – “Any species, strain or biotype of plant, animal or pathogenic agent injurious to plants and plant products, materials or environments and includes vectors of parasites or pathogens of human and animal disease and animals causing public health nuisance”.]
 [The term digital identification tool (DIT) is used throughout this review to include tools for identification as well as diagnostics (in the sense of an “identification” based on crop symptoms].