Ringspot disease of oak

CORaV has been confirmed in ringspot-diseased oaks across Germany, Southern Sweden, and Southern Norway. Typical leaf symptoms—including chlorotic ringspots, chlorotic spots, and mottling—have also been reported in Quercus species in other European countries such as the UK, Hungary, and the Czech Republic. This emphasizes the virus’s geographic spread, symptomatology, and the need for monitoring and management in European oak populations.

Keywords: CORaV, Oak virus, Quercus spp., Leaf symptoms, Virus distribution

Chlorosis and vein yellowing of ash trees

Two novel cytorhabdoviruses—Fraxinus gammacytorhabdovirus 1 (FraxGCRV1) and Fraxinus gammacytorhabdovirus 2 (FraxGCRV2)—have been confirmed in ash trees located in urban street environments in Germany. Their discovery highlights emerging viral threats to urban ash populations and underscores the importance of monitoring, early detection, and management to protect tree health.

Keywords: Fraxinus gammacytorhabdovirus, Ash trees, Cytorhabdovirus, Urban forestry, Virus monitoring

Chlorotic spots on small-leaved lime

Cytorhabdovirus tiliae has been confirmed in lime trees at a nursery in Germany and in buds from a street tree in Berlin. This finding highlights its presence in both cultivated and urban environments, emphasizing the need for monitoring, early detection, and management to safeguard lime tree health.

Keywords: Cytorhabdovirus tiliae, Lime trees, Urban forestry, Virus monitoring, Tree nurseries

Sooty bark disease

The anamorphic fungus Cryptostroma corticale was first isolated from sugar maple (Acer saccharum) logs in 1889 in Canada. Since then, it has been recorded in Europe on sycamore (A. pseudoplatanus), hickories (Carya spp.), and basswoods (Tilia spp.), as well as in North America on maple (Acer spp.). This fungus is notable for its wood-decaying ability and potential impact on forestry and urban trees.

Keywords: Cryptostroma corticale, Acer pseudoplatanus, Wood decay, Forest pathology, Host range

Golden flecking of red ash privet-leaf blotch disease

Privet leaf blotch-associated virus (PrLBaV) was first described in Italy in association with yellow blotching on privet (Ligustrum japonicum) leaves. It has also been reported to affect Fraxinus excelsior, highlighting its potential host range and the need for monitoring and management to protect ornamental and forest trees.

Keywords: Privet leaf blotch-associated virus, Ligustrum japonicum, Fraxinus excelsior, Leaf symptoms, Virus monitoring

Mosaic disease of maple

Maple mottle-associated virus (Emaravirus aceris), Maple emaravirus 2 (MEV-2), and Maple emaravirus 3 (MEV-3) are emerging viral pathogens affecting maple (Acer) species. These viruses are associated with leaf symptoms such as mottling, chlorotic patterns, and reduced vitality, highlighting the importance of monitoring, early detection, and management to protect urban and forest maple populations.

Keywords: Emaravirus aceris, MEV-2, MEV-3, Maple trees, Leaf symptoms

The common mistletoe

The common mistletoe (Viscum album L.) is an evergreen, perennial, epiphytic, hemiparasitic shrub that grows on a wide range of woody plant species. Native to Europe, it is recognized as a plant pathogen, a source of pharmaceutical compounds, and a cultural symbol in mythology, reflecting its ecological, medicinal, and societal significance.

Keywords: Viscum album, Mistletoe, Hemiparasite, Woody plants, Plant pathogen

Shot hole disease of cherry laurel

Several pathogens have been implicated in the development of shot hole disease on cherry laurel, including fungi such as Neofusicoccum parvum and bacteria including Micrococcus aloeverae, Xanthomonas arboricola pv. pruni, and Pseudomonas syringae. Understanding the range of causal agents is essential for accurate diagnosis, monitoring, and effective disease management.

Keywords: Shot hole disease, Cherry laurel, Neofusicoccum parvum, Xanthomonas arboricola, Pseudomonas syringae

Tip chlorosis of beech

Carlavirus fagi, a plant pathogenic virus, has been detected in urban forests as well as in natural and commercial forest ecosystems. This highlights its wide host range and potential impact on tree health, emphasizing the importance of monitoring, early detection, and management strategies to prevent spread and reduce ecological and economic damage.

Keywords: Carlavirus fagi, Plant virus, Forest health, Urban forestry, Disease monitoring