Forestry Branch
Emerald Ash Borer in Manitoba
Host
Ash Tree Identification
Emerald Ash Borer (EAB) Life Cycle
EAB Identification
Damage to trees
Symptoms of EAB damage
EAB Control
Range Map of EAB
EAB Look-alikes
Monitoring EAB
You can help
Emerald ash borer (EAB) was first detected in North America in 2002 in Ontario and Michigan. It is thought that EAB was introduced through ash packing material used in shipments from China. Since then, it has spread to several other states and to Quebec. Native to eastern Asia (China, Korea, Japan, Russia, Mongolia), EAB is well suited to Manitoba’s climate and could establish a population here.
While EAB was originally introduced from Asia, this highly destructive invasive pest continues to spread throughout North America through the movement of nursery stock and raw-untreated ash wood, particularly firewood. EAB has been given a free ride to new areas by unsuspecting campers and cottagers.
Millions of ash trees have been killed in Ontario and the American eastern states. EAB can be very hard to detect in the early stages and often goes unnoticed until it is too late. For this reason, EAB has been difficult to control and manage. It is far better to prevent EAB introductions in the first place and failing that, to find new infestations early.
Emerald Ash Borer
(David Cappaert, Michigan State University, Bugwood.org)
Hosts
EAB only attacks ash trees (Fraxinus species). Mountain ash is not a true ash tree and is not susceptible to EAB. All North American species of ash are vulnerable to EAB. In Manitoba there are two native species of ash; green and black ash. Manchurian ash and cultivars of green, black and Manchurian ash have been planted in many communities and are also vulnerable to EAB.
Ash trees
(David Cappaert, Michigan State University, Bugwood.org)
Ash Tree Identification
Click here for information about identifying ash trees.
Life Cycle
EAB has a one to two year life cycle (two years in lightly infested areas and possibly in colder northern climates). The larvae overwinter under the bark of ash trees and pupate in early spring (mid-April) with adult emergence in late May to the end of June.
The adults feed on ash foliage for two to four weeks that is characterized by a notched feeding pattern on the leaf edges. This stage is not damaging to the trees. From the end of June until the end of August, the adult female lays up to 300 individual eggs (average 75) on the bark or in bark crevices of ash trees.
The larvae bore directly through the bark after hatching and begin feeding in the phloem (food conducting tissue) of the tree creating s-shaped galleries. This is the damaging stage of the insect as the flow of nutrients in the tree is disrupted by the larval feeding.
Description
Adult emerald ash borer
(Pennsylvannia Dept. of Conservation and Natural Resources Forestry Archive Bugwood.org)
The average length for an adult emerald ash borer is 7.5 to 13.5 mm long and 4 mm (1⁄6 in) wide. The larvae are approximately 1 mm in diameter and 26 to 32 mm long, and are a creamy white color.
Larvae
(Pennsylvannia Dept. of Conservation and Natural Resources Forestry Archive Bugwood.org)
Prepupae
(David Cappaert, Michigan State University, Bugwood.org)
Pupae
(David Cappaert, Michigan State University, Bugwood.org)
Damage
EAB larvae feed on the phloem of trees just under the bark and disrupt the flow of nutrients in the tree resulting in the trees death. It takes two to five years for the feeding to kill the infested tree.
At low levels, the EAB is hard to detect, but as the population increases, ash trees start dying. In places like Michigan, where the population of EAB went undetected for many years, millions of ash trees were killed by this pest.
Trees damaged by EAB feeding.
(David Cappaert, Michigan State University, Bugwood.org)
Symptoms
Thinning and dieback of crown.
(Steven Katovich, USDA Forest Service, Bugwood.org)
Vertical cracks, caused by larval activity under the bark.
(David R. McKay, USDA APHIS PPQ, Bugwood.org)
Woodpecker damage, caused by woodpeckers seeking larvae under the bark.
(Jim Tresouthick, Village of Homewood, Bugwood.org)
Epicormic shoots, shoot development beneath larval activity as tree attempts to survive.
(Joseph O'Brien, USDA Forest Service, Bugwood.org)
D-shaped exit holes, caused by the emergence of the adult stage of EAB.
(Daniel Herms, The Ohio State University, Bugwood.org)
Larval galleries under bark.
(James W. Smith, USDA APHIS PPQ, Bugwood.org)
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Control
EAB populations are controlled by removing and destroying infested trees.
Pesticides are available in Canada to control EAB, but they must be applied by a licensed applicator. For more information on pesticides to control EAB go to the Canadian Pest Management Regulatory Agency's (http://pr-rp.hc-sc.gc.ca/ls-re/index-eng.php) label database and do a key word search on Emerald Ash Borer.
It is not recommended that ash trees be treated at this time, since EAB has not yet been found in Manitoba.
EAB Maps
Click here to see a range map of EAB
EAB Look-alikes
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Monitoring
The Canadian Food Inspection Agency is the federal agency responsible for the development of forest policies that prevent the introduction and spread of regulated pests in Canada. Manitoba Conservation, Forestry Branch has been assisting this agency in monitoring for this invasive forest pest in several locations throughout southern Manitoba using large green sticky traps. No EAB have been found in Manitoba to date.
Sticky trap in ash tree
You can help
EAB continues to be spread throughout North America through the movement of ash firewood and other ash products, including ash nursery stock. If you think you have found infested trees or ash material, please call the Provincial Tree Line: 204-945-7866.
PLEASE DO NOT MOVE FIREWOOD!
Do not move firewood long distances. Buy it locally and leave it where you bought it.
Be vigilant. Learn about the signs and symptoms of EAB and report symptomatic ash trees or ash tree products.
Tell others. An informed public is the first line of defense against this destructive pest.
Links
Canadian Food Inspection Agency: http://www.inspection.gc.ca/english/plaveg/for/fore.shtml
Emerald Ash Borer Information Network: http://www.emeraldashborer.info/index.cfm
Survey Guide for Detection of Emerald Ash Borer (PDF): http://cfs.nrcan.gc.ca/publications/download-pdf/26858
A Visual Guide to Detecting Emerald Ash Borer Damage (PDF): http://cfs.nrcan.gc.ca/publications/download-pdf/26856
Emerald Ash Borer Technical Note No. 110: http://cfs.nrcan.gc.ca/pubwarehouse/pdfs/31501.pdf
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