Editing Fraxinus (section)

== Threats ==
[[File:Canker on Ash.JPG|thumb|left|upright|[[Canker]] on an ash tree in North Ayrshire, Scotland]]

=== North America ===
[[File:Agrilus planipennis 001.jpg|thumb|right|upright=0.60|Emerald ash borer]]
The [[emerald ash borer]] (''Agrilus planipennis''), also called EAB, is a wood-boring [[beetle]] accidentally introduced to North America from eastern Asia via solid wood packing material in the late 1980s to early 1990s. It has killed tens of millions of trees in 22 states in the United States<ref>{{cite web |url=http://www.emeraldashborer.info/about-eab.php |website=Emerald Ash Borer Information Network |title=About Emerald Ash Borer |first=Derek|last=Moy}}</ref> and adjacent [[Ontario]] and [[Quebec]] in Canada. It threatens some seven billion ash trees in North America. Research is being conducted to determine whether three native Asian wasps that are natural predators of EAB could be used as a [[Biological pest control|biological control]] for the management of EAB populations in the United States. The public is being cautioned to avoid transporting unfinished wood products, such as firewood, to slow the spread of this insect pest.<ref>{{cite web|title=The Problem|url=http://www.dontmovefirewood.org/the-problem.html|work=Don't Move Firewood|access-date=14 October 2011}}</ref>

Damage occurs when emerald ash borer larvae feed on the inner bark, [[phloem]], inside branches and tree trunks. Feeding on the phloem prevents nutrients and water transportation. If the ash is attacked, the branches can die and eventually the whole tree can as well.<ref>{{cite report |title=Emerald Ash Borer and Your Woodland |series=Extension Bulletin E-2943 |url=http://www.emeraldashborer.info/documents/E-2943.pdf |publisher=Michigan State University Extension |date=September 2007}}</ref> Ways to detect emerald ash borer infestation include seeing bark peeling off, vertical cracks in the bark, seeing galleries within the tree that contain powdery substance, and D-shaped exit holes on the branches or trunk. Not all of these may be present, but any of these warning signs could be an indication of possible infestation.<ref>{{cite report |url=https://emeraldashborerinsouthdakota.sd.gov/PDF/How-To-Identify-an-Ash-Tree-Infested-by-EAB_06-2001-2018.pdf |title=How to Identify an Ash Tree Infested by Emerald Ash Borer |publisher=SDSU Extension |last=Ball |first=John |date=April 2018}}</ref>

=== Europe ===
The European ash, ''[[Fraxinus excelsior]]'', has been affected by the [[fungus]] ''[[Hymenoscyphus fraxineus]]'', causing [[ash dieback]]<ref>{{cite journal|vauthors=Kowalski T |date=2006 |title=Chalara fraxinea sp. nov. associated with dieback of ash (Fraxinus excelsior) in Poland |journal=Forest Pathology |volume=36 |issue=4 |pages=264–270|doi=10.1111/j.1439-0329.2006.00453.x }}</ref> in a large number of trees since the mid-1990s, particularly in eastern and northern Europe.<ref>{{cite journal |vauthors=Halmschlager E, Kirisits T |year=2008 |url=http://www.bspp.org.uk/publications/new-disease-reports/july2008/2008-25.asp |title=First report of the ash dieback pathogen Chalara fraxinea on Fraxinus excelsior in Austria |journal=New Disease Reports |volume=17 |pages=20 |access-date=10 February 2010 |archive-date=29 September 2009 |archive-url=https://web.archive.org/web/20090929053106/http://www.bspp.org.uk/publications/new-disease-reports/july2008/2008-25.asp |url-status=dead }}</ref><ref>{{cite journal |vauthors=Ogris N, Hauptman T, Jurc D |year=2009 |url=http://www.bspp.org.uk/publications/new-disease-reports/ndr.php?id=019015 |title=Chalara fraxinea causing common ash dieback newly reported in Slovenia |journal=New Disease Reports |volume=19 |pages=15 |access-date=10 February 2010 |archive-date=9 November 2009 |archive-url=https://web.archive.org/web/20091109042759/http://www.bspp.org.uk/publications/new-disease-reports/ndr.php?id=019015 |url-status=dead }}</ref> The disease has infected about 90% of Denmark's ash trees.<ref name=bbc-20121025>{{cite news |url=https://www.bbc.co.uk/news/science-environment-20079657 |title='Ash dieback' fungus Chalara fraxinea in UK countryside |work=BBC |date=25 October 2012 |access-date=25 October 2012}}</ref> At the end of October 2012 in the UK, the [[Department for Environment, Food and Rural Affairs|Department for Environment, Food and Rural Affairs (Defra)]]  reported that ash dieback had been discovered in mature woodland in [[Suffolk]]; previous occurrences had been on young trees imported from Europe.<ref>[https://www.bbc.co.uk/news/science-environment-20079657 BBC News 'Ash dieback' fungus, ''Chalara fraxinea'' found in UK countryside. Retrieved 25 October 2012].</ref> In 2016, the ash tree was reported as in danger of extinction in Europe.<ref>{{cite news |last=Marshall |first=Claire |date=23 March 2016 |title=Ash tree set for extinction in Europe |work=BBC |url=https://www.bbc.com/news/science-environment-35876621}}</ref>