All these diseases occur in the city of Zurich:
- Asian longhorn beetle
- Pear Grate
- Brown spot disease
- Boxwoodzünsler
- Ash shoot death
- Fire blight bacterium
- Pine shoot death
- Chestnut leaf miner moth
- Massaria
- Pseudomonas - bark disease
- Sooty bark disease
Asian longhorn beetle:
Affected tree species:
maple, birch, beech, hornbeam, hazel, poplar, plane tree, horse chestnut, willow
First occurrence:
2011
Damage pattern:
Beetles are shiny black colored with a white spotted pattern and they make big, circular exit holes.
Female beetles lay about 30 eggs in the bark, which cause extensive feeding damage.
Risks:
weakens the trees and makes them susceptible to diseases and wind break.
Obligation to register:
yes
Fire blight bacterium:
Affected tree species:
Apple-, pear- and quince tree, medlar, medlar of wool, dwarf medlar, glittering medlar, firethorn, false quince, hawthorn, mountain ash, rock pear
First occurrence:
1989
Damage pattern:
Individual flowers and clusters of flowers wilt and become dark brown to black without falling off. It spreads further through leaves and branches until the whole plant dries up and dies. It then looks like it has been scorched by fire. Is transmitted from infested shoots by flower-visiting insects, wind, rain and birds as well as by tools, shoes and clothes.
Risks:
If no countermeasures are taken, major economic damage can result, especially to orchards.
Obligation to register:
yes
Sooty bark disease:
Affected tree species:
sycamore maple, rarely pointed and field maple
First occurrence:
2009
Damage pattern:
Dead bark or growth layer, dark slime flow spots on the stem. Later, dying and wilting appearances of the crown follow. In the trunk cross section large greenish to bluish discolorations appear. After the death of the tree, the bark usually peels off at the trunk base and the spore deposits formed by the fungus appear in the form of a black, almost flat, Russian-like coating.
Promotion of disease: dry-hot conditions with simultaneous lack of water
Risks:
Dead trees quickly become susceptible to wind breakage due to the onset of white rot.
The spores of the fungus pose a danger to humans, which can lead to an allergic inflammation of the pulmonary alveoli when inhaled.
Appropriate protective measures are therefore necessary during felling and clearing operations
Obligation to register:
no
Neophytes
Neophytes are plant species that humans introduce from other continents into new areas. These species are not native to these areas.
Few species spread strongly. They become invasive and thus cause problems.
Problems:
- they endanger human and animal health: through pollen, phototoxic burns and poisons
- they reduce biodiversity: by displacing other species, mixing with related species and changing habitats
- they damage the infrastructure buildings: which makes the maintenance of roads, railways, green areas more expensive
Measures: (Action plan invasive neophytes)
Control: prevent the spread and reduce negative effects.
Monitoring: all urban areas are monitored and controlled.
Coordination: the City of Zurich's service departments coordinate among themselves and with neighboring municipalities and owners of large plots of land as well as with specialists.
Informing: Private individuals receive information and the public is made aware of the problem.
Pflanzenschädlinge und -krankheiten (stadt-zuerich.ch)
Link 2