Updated and annotated review of Tetranychidae occurring in mainland Portugal, the Azores, and Madeira Archipelagos

Data on the diversity, distribution, and main hosts of spider mites (Acari: Tetranychidae) are scarce in the Iberian Peninsula, particularly for Portugal, where only 21 species are recorded on the mainland and in the Azores and Madeira archipelagos. Moreover, the scientific information is mainly available in national publications, and difficult to access for international researchers. In this paper, we review the literature dealing with spider mites in mainland Portugal and the archipelagos of the Azores and Madeira, compiling and synthesizing the most relevant information on their distribution, hosts and pest potential. Further information was obtained by verifying slides in the acarological collection of the Instituto Nacional de Investigacao Agraria e Veterinaria (INIAV), the most important national collection, and by verifying mites collected on different plant hosts during the period 2018-2020. In total, we found records for 28 spider mite species in Portugal, comprising nine Bryobiinae and 19 Tetranychinae, and including new national records for Stigmaeopsis nanjingensis and Eotetranychus tiliarium. Additionally, we record a new exotic mite species for the mainland, Eotetranychus lewisi, which was found in two localities in the Algarve District on leaves of Euphorbia pulcherrima. This is the first record for continental Europe of an established population in outdoor conditions of this regulated quarantine pest. We also comment on the presence of seven species not reported by international taxonomic databases but already recorded from Portugal: Aplonobia histricina, Eotetranychus rubiphilus, Schizonobia sycophanta, Tetranychus kanzawai and Tetranycopsis horridus (at a national level), and Oligonychus perseae and Panonychus citri (for the mainland). New host records are given for Bryobia praetiosa, Petrobia (Tetranychina) harti, S. sycophanta, E. coryli, E. rubiphilus, Tetranychus kanzawai, Tetranychus lintearius, Tetranychus ludeni and Tetranychus turkestani.