Fifties of the last century, the United States passed by the European fir ball aphids, being seriously eroded cedar Virginia USA Canaan Valley National Wildlife Refuge in the region, the most popular in the United States the land of Canaan and Fraser two kinds of Christmas trees are a lot of bending , yellow and death. This exotic pest, breed quickly, no natural predators, and wild use of chemical pesticides is ineffective, making it difficult to be eliminated, eradicated. Sum insured institutions are trying to be controlled through the use of biological control methods.