Foliofagi tworzące galasy na Fagus sylvatica L.

Observations on the occurrence of foliophages inducing plant−galls in European beech Fagus sylvatica were performed over 2010−2011, at four forest stands located in Bydgoszcz. Analyses of the material collected demonstrated the presence of two Diptera species representing Cecidomyiidae family: Hartigiola annulipes Hartig. and Mikiola fagi Hartig. During two vegetation seasons there were collected 15,092 plant−galls. Most of them were reported in 2010 (67.57%) and much fewer – in 2011 (32.43%).