Prince Gallitzin, Cambria County “In Pennsylvania, these destructive, invasive insects go through cycles where outbreaks occur every five to 10 years,” said DCNR Forest Health Manager Dr. Donald Eggen. “Populations had declined in years past thanks to the gypsy moth fungus disease and wet spring weather but that no longer is the case for 2021.” The gypsy moth suppression program is conducted with the goal of preventing defoliation so that trees do not become stressed and succumb to disease, other insect pests, or drought, the DCNR said. Aerial spraying will be conducted by helicopter and fixed-wing aircraft. Targeted sites are determined by surveys of egg masses and other indicators across the state indicating gypsy moth populations are increasing and have the potential to cause major defoliation.