Crayfish plague	Status LU: unknown, 1st record LU 1880, ITW: 1880
	Kriibspescht	Status Eur.: established, 1st record 1859 (Italy)
	Peste de l’écrevisse	RA: ISEIA: n/a Harmonia+: n/a
	Krebspest	Wikipedia: | Wikispecies: | CABI
	Rivierkreeftenplaag	Back to the list of neomyceta

Brief description

Aphanomyces astaci Schikora, 1906 is a water mold that infects freshwater crayfish. It is the cause of crayfish plague that can provoke the death of the infected individuals. Transport of signal crayfish, red swamp crayfish and infected native European freshwater crayfish between waters is the main cause of contamination, though the disease can also be spread via items that have been in contact with contaminated water, such as a fishing tackle or footwear. The spores are sensitive to high or low temperatures.

The natural range of A. astaci is likely to be North America. It has been found in North American crayfish sampled in North America. Any occurrence of A. astaci outside of North America is currently considered as an exotic appearance of the pathogen. Crayfish plague first arrived in Europe in Italy in 1859, either with imported crayfish from North America or in ballast water discharge. After its original introduction in Italy, it spread quickly through Europe and was discovered for example in France in 1874, in Germany in 1877, in Luxembourg and Belgium around 1880, in Sweden in 1907, in Spain in 1972, in Great Britain in 1981 and in Ireland in 1987.(CABI 2022, Wikipedia contributors 2022).

Status and distribution in Luxembourg

There is no recent distribution data concerning Aphanomyces astaci Schikora, 1906 in Luxembourg.

Risk assessment

ISEIA protocol

Not assessed yet.

Harmonia+ protocol

Not assessed yet.

Worldwide distribution

Bibliography

• CABI, 2022. Aphanomyces astaci. In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2022-11-14]
• Wikipedia contributors, 2022. ‘Crayfish plague’, Wikipedia, The Free Encyclopedia, 27 September 2019, 08:25 UTC, <https://en.wikipedia.org/wiki/Crayfish_plague> [accessed 2022-11-14]

 Page content last updated on 2023-09-27.

	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

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.

 Page content last updated on 2020-09-23. Last proofread by Caroline Grounds on 2019-12-12.