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Corythucha arcuata, the North American oak lace bug feeding on leaves of “white oaks” in its native range, was discovered in Europe in 2000 (in northern Italy). Since that time it has spread rapidly in several European countries where its population outbreaks have been observed. However, the species was not reported from Poland, so far. In this study the potential geographic distribution of Corythucha arcuata was modelled using maximum entropy (Max-Ent) in order to predict the regions of Poland where it would have found the best environmental conditions for its further spread. The results showed that the highest habitat suitability areas were located in the central-eastern parts of the Lower Silesian Voivodeship and in the central part of the Małopolska Voivodeship. However, a precise prediction of the routes of migration of the oak lace bug into the territory of Poland, and the year when it appears in our country is impossible to estimate.

Invasive pest oak lace bug (Corythucha arcuata), (Hemiptera: Tingidae) was first recorded in eastern Croatia in 2013 in lowland stands of pedunculate oak (Quercus robur L.), from where it expanded to the west causing summer yellowing and intensive chlorotic damages of oak leaves. In 2018 entomopathogenic fungus Beauveria pseudobassiana Rehner et Humber (Hypocreales Cordycipitaceae) was isolated from several dead C. arcuata adults found in moss, where one part of population usually overwinters. Two isolates were used for testing of fungus virulence against C. arcuata under laboratory conditions. After preparation of conidial suspensions with desired 1 x 108 concentrations healthy adults of C. arcuata were treated by spraying the moss where they were previously put on. Results showed no difference in mortality rate between isolates (96-97%), but isolate BBCNK1 produced mycosis value of 49 % which was higher than mycosis value of 32 % produced by isolate BBC10, with 4 % of mycosis value in control. In nature these results indicate possible rise of entomopathogenic B. pseudobassiana natural inoculum up to 12 X. Moreover, we estimated the number of overwintering adults in 1 m2 of moss by counting them and calculating their average number in 6 m2 of moss collected in six different locations in infested oak forest. Results demonstrated high rate of dead overwintering individuals, with approximately 15 % of them infested by various entomopathogenic fungus. The results presented here will be beneficial for future investigations of effectiveness of naturally occurring B. pseudobassiana on C. arcuata in field conditions.