Over the last few decades, globalization and global trade have increased the risk of the vehiculation of invasive organisms, which has had multiple negative effects, both economic and ecological. Through this study, we aimed to produce a report on the first record of the invasive scale insect Pulvinaria hydrangeae (Stein. 1946) in Brașov County in central Romania. It was found on two native tree species: sycamore (Acer pseudoplatanus) and linden (Tilia cordata). In this paper, we (i) highlight the list of possible hosts, (ii) provide a general outlook on infestations and (iii) review the control options for this particular pest. Because early detection and quick reporting are the most important actions in the successful management of invasive species, in general, we also provide a synthetic morphological description of the adult female specimens and ovisacs. Due to natural occurrence, our findings highlight the potential risks posed by the infestation of this insect to native tree species belonging to the Acer and Tilia genera. Because of the temperate climate in Romania and the fact that females are wingless, the new infestations will probably be made through the vehiculation of infested plants, rather than through natural spreading. However, because of global warming, the chances of this species surviving during the winter are likely to increase, making northern expansion of the cottony hydrangea scale feasible.
Keywords: Acer sp.; Pulvinaria hydrangeae; Tilia sp.; cottony hydrangea scale; invasive scale; ovisac; pest species.