n/a	Status LU: established. 1st record: 2012.
	Falsche wäisse Stillbecherchen	Status Eur.: established.
	n/a	RA: ISEIA: A3. Harmonia+: 0,16.
	Falsches weißes Stängelbecherchen	Wikipedia: | Wikispecies: n/a (2020) | CABI
	Vals essenvlieskelkje	Back to the list of neomyceta

Report the species

→ Report Hymenoscyphus fraxineus to the National Museum of Natural History.

Brief description

Hymenoscyphus fraxineus (T. Kowalski) Baral, Queloz, Hosoya (Baral et al. 2014) is an ascomycete fungus that causes ash dieback, a chronic fungal disease of ash trees (Fraxinus excelsior) in Europe characterised by leaf loss and crown dieback in infected trees. It was first described in Japan (Zhao et al. 2012).

Hymenoscyphus fraxineus is an invasive anamorphic fungal pathogen which comes from the Far East and has greatly expanded its reach throughout Central and Western Europe in recent years. Studies of herbarium material show that Hymenoscyphus fraxineus was already present in Central Europe in 1978 (Queloz et al. 2011). It is now entrenched in Europe. It is closely related to a native fungus Hymenoscyphus albidus, which is saprotrophic and also grows on the petioles of dead leaves of ash trees.

The entire natural range of known hosts, including North Africa, Russia and south-west Asia, is currently threatened by ash dieback, with large areas already affected. Little is known about the susceptibility of the other species of ash in temperate zones (CABI 2019).

Status and distribution in Luxembourg

Hymenoscyphus fraxineus (T. Kowalski) Baral, Queloz, Hosoya was first recorded on 16th June 2012 in Bois de Cessange (Municipality of Luxembourg) under its synonym Hymenoscyphus pseudoalbidus (Garnier-Delcourt et al. 2013: 35-36). It was reported in 2002 in Germany (Heydeck et al. 2005) and in 2010 in Belgium (Delhaye et al. 2010). The fungus is rapidly spreading throughout Luxembourg and in 2014 it was found in all regions of Luxembourg: a considerable number of young ash trees are affected while only a part of the elder ash trees show dieback symptoms.

Only few observations have been reported to the Recorder-Lux database so that the map does not reflect the actual distribution of the species, occurring everywhere where ash occurs.

Risk assessment

ISEIA protocol

B3 (3+3+3+1) = Watch List. First assessed on 22 September 2017 by Christian Ries and Yves Krippel.

Harmonia+ protocol

Overall risk score 0,16 = (Overall Invasion score 0,79 x Overall Impact score 0,20) (Non publ. RA by C. Ries).

Worldwide distribution

Bibliography

• Baral H-O, V Queloz & T Hosoya (2014) Hymenoscyphus fraxineus, the correct scientific name for the fungus causing ash dieback in Europe. IMA Fungus 5(1): 79-80.
• CABI, 2019. Hymenoscyphus fraxineus (T. Kowalski) Baral, Queloz, Hosoya. In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2020-04-28]
• Garnier-Delcourt M, G Marson, Ch Reckinger, B Schultheis & M-T Tholl (2013) Notes mycologiques luxembourgeoises. VII. Bull. Soc. Nat. luxemb. 114: 35-54. (Pdf 6.5 MB)
• Heydeck P, M Bemmann, H-G Kontzog (2005) Triebsterben an Gemeiner
  Esche (Fraxinus excelsior) im nordostdeutschen Tiefland. Forst und Holz 60: 505–506.
• MNHNL, iNaturalist & GBIF, 2020. Hymenoscyphus fraxineus (T. Kowalski) Baral, Queloz, Hosoya in MNHNL-mdata, online portal combining species observation from Recorder-Lux, iNaturalist and GBIF. National Museum of Natural History, Luxembourg. URL: https://mdata.mnhn.lu [accessed 2020-04-28]
• Queloz V, C R Grünig, R Berndt, T Kowalski, T N Sieber & O Holdenrieder (2011) Cryptic speciation in Hymenoscyphus albidus. For. Path. 41: 133–142, published online 30 March 2010 – doi:10.1111/j.1439-0329.2010.00645.x
• Zhao Y-J, T Hosoya, H-O Baral, K Hosaka & M Kakishima (2012) Hymenoscyphus pseudoalbidus, the correct name for Lambertella albida reported from Japan. Mycotaxon 122: 25-41.