NATIVE RANGE: North and Central America

FIRST FINDING IN SLOVENIA: 2008

PATHWAYS: brought with infected host plants; secondary spontanuous spreading

POSSIBLE TO FIND: year-round

DESCRIPTION: The first symptoms of this disease are yellow spots on pine needles, which are sometimes filled with resin. These spots first appear by the end of summer. Later, these spots turn dark brown, and elongate, spreading to the tips of the needles and causing their dieback. In late autumn dense hyphae clusters, which look like raised black spots, appear beneath the epidermis of the dying needles. In moist weather, fruiting bodes are formed which discharge large numbers of spores in the form of an olive-green slime.

HOST PLANTS: Mountain pine (Pinus mugo) is highly susceptible while Scots pine (P. sylvestris) and Aleppo pine (P. halepensis) may also be affected but black pine (P. nigra) only rarely so.

STATUS: Locally present throughout Europe. In Slovenia found in the surroundings of Bled, Ljubljana, Celje, Kostanjevica na Krki, Čatež. At all these sites eradication actions are carried out. It is possibly spread in the entire Soča valley.

SIMILAR SPECIES: Dothistroma blight (Dothistroma pini), Cyclaneusma needle-cast (Cyclaneusma minus), Sphaeropsis shoot-killing of pine (Diplodia pinea) and Lophodermium needle cast (Lophodermium seditiosum).

SOURCE: Field Guide to Invasive Alien Species in European Forests