Discovery and history

C. corticale was first isolated from maple, most probably sugar maple (A. saccharum Marshall) firewood in London, Ontario (Canada) in 1889 and called Coniosporium corticale Ellis & Everh. (Ellis & Everhart, 1889). It was described as a non-parasitic fungus. Other reports of the fungus were also restricted to the Great Lakes region, particularly in Wisconsin and Michigan during the first half of the 1900s (Towey et al., 1932; Gregory and Waller, 1951). Meanwhile, in Europe this fungus was isolated in Essex (UK) from sycamore (A. pseudoplatanus) by Gregory, Peace and Waller (1949) but remained unidentified until the study performed by Gregory and Waller (1951) where it was firstly described as C. corticale. This study was performed in Wanstead Park in London, where the fungus was observed on one dead sycamore tree in 1945 and in about 40 dead or dying sycamores in 1948. Subsequent surveys in 1949 and 1950 revealed the occurrence of infections in more than 150 trees. Apart from this particular outbreak in UK, along the 20^th century only occasional epidemics were described in France (Moreau and Moreau, 1954), Italy (Wilkins, 1952) and Germany (Plate and Schneider, 1965). In France, Moreau and Moreau (1954) described the occurrence of SBD not only in sycamore but also in Norway maple, field maple and one case in an ash-leaved maple. During the last century the incidence of SBD was increasing and the spread of the pathogen in Europe is notorious with several records in Central Europe (Cech, 2004, 2019; Metzler, 2006), south-eastern Europe (Bencheva, 2014), southern Europe (Longa et al., 2016) and eastern Europe (Gninenko et al., 2024).