Invasion of the oak lace bug Corythucha arcuata (Say.) in Romania: a first extended reporting

In the context of globalization, the biological invasions affect all the countries, including Romania, where this phenomenon is increasingly visible in the last years. Besides the invasive forest insects already known to be established in Romania, a new species - Corythucha arcuata (Say, 1832), commonly known as the oak lace bug and originating in North America, appeared in the last years. It was reported for the first time in Romania in 2015, and it spread across the country in 2016-2017. In order to detect the species and to draw its distribution area, a species identification sheet, as well as a working protocol were developed, considering the insect morphology and the type of attack. During the vegetation seasons 2016 and 2017, the species was found in 67 out of the 124 surveyed locations, mainly in the southern and western parts of the country, but also in the eastern part. The main host species of the oak lace bug were Quercus robur, Q. petraea, Q. cerris, Q. frainetto, and Q. pubescens. It attacked the host trees in all habitats (tree stands, parks, nurseries, isolated trees etc.) and the intensity of attack varied from 1% to 100% of the leaves.