The spider mite Oligonychus yothersi (Acari: Tetranychidae), a new alien pest in Europe: joint records from insular Portugal, Spain and Italy revealed by integrative taxonomy

The spider mite Oligonychus yothersi (McGregor, 1914) is for the first time reported in Europe from four European insular regions with mild oceanic and Mediterranean climates- the Azores and Madeira archipelagos (Portugal), Canary Islands (Spain) and Sicily (Italy). Although populations were detected in the Canary and Azores islands since 2006 and 2015, respectively, their taxonomic identification remained unresolved due to the lack of male specimens and the unavailability of DNA reference sequences. An integrative taxonomic approach based on morphological traits of two males collected in September 2024 and on recently and previously obtained COI DNA sequences from multiple localities and host plants samples allowed its accurate identification and host plant records. Specimens have been collected from a range of 21 host plants, including native, cultivated and invasive species. New host plant records suggest host adaptation in the colonized areas. Six COI haplotypes have been identified in the studied areas. COI DNA sequences obtained from accurately identified specimens which can support further identifications are provided. Its pest status on other continents is detailed along with the warning on the risk that this spider mite poses for Europe.