Bojan Stojnić, Katarina Mladenović, Biljana Vidović, Nikola Anđelković, Slobodan Milanović
During phytosanitary monitoring of ornamental conifers conducted across multiple regions of Serbia, two species of spider mites, Eotetranychus libocedri (McGregor, 1936) and E. thujae (McGregor, 1950), were recorded for the first time. Eotetranychus libocedri was found on Platycladus orientalis L. (Franco), Thuja occidentalis L., and Cupressus × leylandii A.B. Jacks & Dallim, while E. thujae was detected on T. occidentalis. These records extend the distribution area of these two allochthonous species in Europe. Monitoring alien arthropod species in Europe is crucial, as they pose a risk to native flora and fauna and can cause significant economic losses. Together with previous findings, the number of registered species of the family Tetranychidae in Serbia now totals 47 across 10 genera.