The research projects initiated through Euphresco/EUPHRESCO III are small to medium‐sized projects commissioned to provide evidence on specific questions. The research projects are not necessarily intended to deliver break‐through science and innovation but fall into the category of explorative and applied science needed to support policy (Giovani et al., 2019). Thus, the research activities commissioned through the Euphresco/EUPHRESCO III joint calls will support regulatory aspects and, in particular, the activities of the National Plant Protection Organizations (NPPOs). As policymakers are one of the target groups of Euphresco/EUPHRESCO III, factsheets for policymakers are published to provide recommendations from national and transnational research activities.

The first series of factsheets focusses on diagnostics. A general introduction on the topic is followed by the recommendations for each of the nine regions identified in the EUPHRESCO III project, namely: Africa, Australia, Central Asia, Latin America and the Caribbean, North America, Northern Europe, the Pacific islands, South-East Asia, and Southern Europe and Mediterranean.

Reliable and rapid diagnostic processes are essential to support inspection activities conducted by NPPOs in the framework of their official mandate, and to evaluate the efficacy of measures taken. Official controls aim to prevent or reduce the risk of introducing new pests through the agri-food trade and to protect consumer interests. The reliability and consistency of these controls contribute to effective trade. In this context, validated and internationally accepted measures are of the utmost importance, as they support the harmonisation of detection and identification procedures worldwide and contribute to greater transparency and comparability in the diagnosis of regulated pests (Giovani et al., 2017).

The pests covered are:
▪Bacteriology: ‘Candidatus Liberibacter americanus’, Ralstonia solanacearum, Xanthomonas citri subsp. Citri, Xylella fastidiosa.
▪Entomology: Bactrocera dorsalis, Diaphorina citri, Helicoverpa armigera, Spodoptera frugiperda, Tuta absoluta
▪Mycology: Colletotrichum spp., Fusarium oxysporum f. sp. cubense Tropical Race 4 (Foc TR4), Phyllosticta citricarpa, Phytophthora spp.
▪Nematology: Meloidogyne spp.
▪Virology and Phytoplasmology: banana bunchy top virus (BBTV), tomato brown rugose fruit virus (ToBRFV), various plant viruses and viroids.