The conducted studies comprised the analyses of activity of extracts derived from selected plants of the Geranium family on some processes of large white butterfly (Pieris brassicae) development (oviposition, survival of eggs and caterpillar feeding). The results proved that all tested extracts showed activity against large white butterfly. Geranium pratense L. and Geranium senquineum L. showed better activity than other Geranium plants. Water extracts from these species protected cabbage plants against laying eggs, while applied on eggs caused their mortality. Alcohol and water
extracts from G. pratense L. and water extracts from G. senquineum L. increased an amount of food put on mass gain of caterpillars.
