New species of three monophagous arthropods (Acari & Hemiptera) associated with common walnut (Juglans regia) in Latvia

Three arthropods, including one eriophyoid mite species, Aceria erinea, and two aphid species, Chromaphis juglandicola and Panaphis juglandis, were recorded in Latvia for the first time. These species are monophages and all are associated with common walnut, Juglans regia. All three species were recorded from several localities in Kurzeme and Zemgale region in Latvia, and one species, P. juglandis was found also in Sigulda (Vidzeme region), reaching the northernmost confirmed distribution in eastern Baltic region. P. juglandis was the most abundant species and was recorded from all localities inspected, but these aphids did not occur on all trees in each locality.