A Survey of the Status of Beech White Scale and Beech Bark Disease Symptoms in Forests in the North of Iran (A Case Study inMazanderan Province)

Due to the importance of the beech trees which are one of the most valuable species of tree in the north forests of Iran, the mass growth of the Cryptoco ccus fagi, which can be the vector of Nectria SP., and cause the beech bark disease, brought about some worries. So in order to prevent the probability of any danger, the condition and biology of the above-mentioned pest, Nectria SP., and the parasitic fungi was studied. After identifying the areas with high infection to the pest and the probable existence of the disease, the sample pests were collected. This Cryptococcus fagi can be the carrier of the Nectria SP. fungi, the cause of the bark disease on the beech trees the symptoms of which exist in some areas in the north of Iran at the present time. There are some black spots as big as a 10-rial coin under the tree bark which seem reddish orange. There are also reddish-brown oozes or some black oozes from the decayed parts of the tree. These are often the first symptoms of the trees attacked by the Nectria Sp. The inner and outer parts of the bark die due to the growth (invasion) of the fungi. The tree’s textures often produce callose as a result of the growth of this fungus, and the bark becomes thick and rough, which then creates small cancerlike injuries like the mouth of a volcano. The reddish protis with spores inside which are certainly the symptoms of the disease appear on these trees. Finally, the tree trunk will be surrounded by these dead textures and will die as its dead textures increase. The beech trees dying and drying due to the Nectria Sp.can be seen from a far distance.