INSECT DEFOLIATORS AND THEIR INFLUENCE ON OAK FORESTS IN THE DJERDAP NATIONAL PARK, SERBIA

Abstract- The study of oak phytophagous insects was performed in the period 1992-2010 in the region of the Djerdap National Park. More than a third (36.67%) of the phytophages in oak forests are frequent and can occasionally cause local outbreaks. The early spring defoliator phytophages so far identified in the oak forests of the Djerdap National Park are outbreak species and are significant agents of forest ecosystem degradation and decline. The most frequent species are Tortrix viridana and Operophtera brumata. It was found that Quercus petraea was more affected by dieback then Q. cerris and Q. frainetto