In 2000 the analytical studies were conducted in the species composition of galls occurring on the leaves of beech Fagus sylvatica L. and pedunculate oak Quercus robur L. in southern Poland.  Materials were collected in three localities: the Wolski Forest – near an urban agglomeration of Kraków, the Ojców National Park and in a managed forest-the Andrychów Forest District.  In each localities 2000 leaves of beech and 2000 leaves of oak were randomly collected; in total 6000 leaves of each tree species were tested.

In the case of  F. sylvatica, a total of 1214 galls were found.  The galls represented 2 maker-species, namely Hartigiola annulipes HTG. (377 galls) and Mikiola fagi HTG. (837 galls) (Diptera, Cecidomyiidae).

In the case of Q. robur, a total of 2246 galls, including 1028 in the Andrychów FD, were found.  The galls represented 12 insect species, i.e. 10 from Cynipidae (Hymenoptera) and 2 from Cecidomyiidae (Diptera).  The frequency of gall occurrence varied considerably in the investigated lacalities.