LAUSR

Abstract Phytoseiids are important biological control agents on different cultivated plants. This work aimed to know the diversity of phytoseiids and compare the abundance and richness of these mites found in grape-producing regions located in northern Portugal. Samplings were conducted in the subregions of Ave, Cávado, Douro, Lima and Minho Rivers between July and September 2017, in 25 vineyards (three in Ave, four in Cávado, eight in Douro, five in Lima and five in Minho Rivers), by collecting 50 leaves/vineyard. A total of 4,372 phytoseiid mites were found, and the highest abundance of phytoseiids per leaf was in Lima, with an average of 6.4, followed by Douro and Minho, with 2.5 and Ave, with 2.0. The highest richness was found in Ave and Douro, with 80% of the species reported. Typhlodromus pyri predominated in nearly all rivers, except when comparing Ave versus Douro, Cávado versus Douro and, Cávado versus Minho; in these cases, Kampimodromus aberrans predominated in Douro and Minho. This also occurred when K. aberrans and Typhlodromus exhilaratus were compared between Douro and Minho. Comparing Ave and Minho, T. exhilaratus predominated in Minho. Knowing about the phytoseiids present in the studied regions of northern Portugal helps develop biological control strategies and balance these agroecosystems.