Dothistroma needle blight (DNB) is one of the most important diseases of pine. Although its notoriety stems from Southern Hemisphere epidemics in Pinus radiata plantations, the disease has increased in prevalence and severity in areas of the Northern Hemisphere, including Europe, during the last two decades. This increase has largely been attributed to expanded planting of susceptible hosts, anthropogenic dispersal of the causative pathogens and changes in climate conducive to disease development. The last comprehensive review of DNB was published in 2004, with updates on geographic distribution and host species in 2009. Importantly, the recognition that two species, Dothistroma septosporum and D. pini, cause DNB emerged only relatively recently in 2004. These two species are morphologically very similar, and DNA-based techniques are needed to distinguish between them. Consequently, many records of host species affected or geographic location of DNB prior to 2004 are inconclusive or even misleading. The objectives of this review were (i) to provide a new database in which detailed records of DNB from 62 countries are collated; (ii) to chart the current global distribution of D. septosporum and D. pini; (iii) to list all known host species and to consider their susceptibility globally; (iv) to collate Drenkhan et al. 410 |

Summary Dothistroma needle blight (DNB), caused by Dothistroma septosporum and Dothistroma pini, and brown spot needle blight (BSNB), caused by Lecanosticta acicola, are some of the most serious and damaging foliar diseases of pines (Pinus spp.). Lecanosticta acicola is reported for the first time from Ireland and Portugal and confirmed from the Black Sea coast of Russia (Krasnodar region, Sochi). It has also been recovered from the first, and only, reported site in Latvia 4 years after efforts to eradicate it were undertaken. Dothistroma septosporum is reported for the first time from Ireland on Pinus sylvestris and Pinus radiata. It was also found in Comunitat Valenciana, Spain, and confirmed as the causal agent of the disease in Bulgaria. Dothistroma pini was found in Aragon, Spain, and in Arkansas, USA, where it was found on Pinus elliottii, a new host for this pathogen. A new ITS haplotype of D. septosporum is reported from the Bulgarian isolates and a new ITS haplotype of D. pini from the Arkansas isolates. These new country and regional reports extend the geographical and host range of these pathogenic fungi and continue a trend seen since the 1990s. Of particular concern are the geographically widespread new reports of L. acicola from the most north‐ and south‐westerly (Ireland and Portugal) to the most south‐easterly (Russia) regions in Europe, suggesting that not only is this pathogen continuing to spread in Europe but also is well adapted to a wide range of climatic conditions.

Fusarium circinatum, the causal agent of pine pitch canker (PPC), is currently one of the most important threats of Pinus spp. globally. This pathogen is known in many pine-growing regions, including natural and planted forests, and can affect all life stages of trees, from emerging seedlings to mature trees. Despite the importance of PPC, the global distribution of F. circinatum is poorly documented, and this problem is also true of the hosts within countries that are affected. The aim of this study was to review the global distribution of F. circinatum, with a particular focus on Europe. We considered (1) the current and historical pathogen records, both positive and negative, based on confirmed reports from Europe and globally; (2) the genetic diversity and population structure of the pathogen; (3) the current distribution of PPC in Europe, comparing published models of predicted disease distribution; and (4) host susceptibility by reviewing literature and generating a comprehensive list of known hosts for the fungus. These data were collated from 41 countries and used to compile a specially constructed geo-database. A review of 6297 observation records showed that F. circinatum and the symptoms it causes on conifers occurred in 14 countries, including four in Europe, and is absent in 28 countries. Field observations and experimental data from 138 host species revealed 106 susceptible host species including 85 Pinus species, 6 non-pine tree species and 15 grass and herb species. Our data confirm that susceptibility to F. circinatum varies between different host species, tree ages and environmental characteristics. Knowledge on the geographic distribution, host range and the relative susceptibility of different hosts is essential for disease management, mitigation and containment strategies. The findings reported in this review will support countries that are currently free of F. circinatum in implementing effective procedures and restrictions and prevent further spread of the pathogen.

The invasive pathogen Phytophthora ramorum is the cause of 'sudden oak death', a dieback and mortality of more than one million live-oak and tanoak trees along 1500 km of near-coastal native forest in California and Oregon since 1995 (Rizzo et al., 2002; Frankel, 2008 (Fig. 4)

Dothistroma needle blight (DNB) is one of the most devastating needle diseases on Pinus spp. worldwide. Ever since the description of the causal agent of the disease in Europe in 1911 as Cytosporina septospora, and independently in the USA in 1941 as Dothistroma pini, there has been considerable taxonomic discordance regarding the name of the pathogen used in literature. This was compounded both by the proposal of different varieties of the pathogen based on differences in spore size and the application of dual nomenclature where three names, Scirrhia pini, Eruptio pini andMycosphaerella pini, were used to describe the sexual morph of the fungus. More recent studies using sequence-based methods revealed that DNB can be caused by either one of two distinct species, that is D. septosporum and D. pini. These important species have not been adequately typified, and this perpetuates lack of stability for their names. In this study, these names are fixed to reference sequences linked to living cultures representing type specimens. To achieve this goal, we designate an epitype for D. pini and a neotype for D. septosporum. The known polymorphism in the ITS region, the barcoding gene for these fungi, is characterized and a complete taxonomic history is provided for the genus Dothistroma.