Preliminary report on the occurrence of cryphonectria parasitica (murrill) barr on different tree species in friuli venezia-giulia (Italy)

Within the frame of the forest phytopathological inventory of the Friuli Venezia-Giulia district, several groups of oaks (Quercus spp.) infected with the chestnut blight fungus ('Cryphonectria parasitica (Murr.) Barr) were observed. Most of the oaks were found in old chestnut orchards. Because C. parasitica can infect several tree species, the hypothesis was tested that insects boring both in chestnut and oaks may act as possible vectors of fungal spores. Several oak trees infected with C. parasitica and attacked by xylophagous insects were cut down and put into insect emergence boxes. Emerged insects were then washed and the spore load was evaluated. Scolytus intricatus (Ratz.) and Xyleborus monographus (F.) were the only bark beetle species to emerge, and both are able to attack chestnut. All insects were contaminated with several fungi. Scolytus intricatus might be an efficient vector, because its life cycle includes a maturation feeding in the crown of healthy oaks, whereas this is...