Emerald ash borer

? Emerald ash borer
Plant Info
Scientific classification
Kingdom: Animalia Phylum: Arthropoda Class: Insecta Order: Coleoptera Family: Buprestidae Genus: Agrilus Species: A. planipennis
Binomial name
Agrilus planipennis Fairmaire, 1888

The emerald ash borer (Agrilus planipennis or Agrilus marcopoli and EAB) is a green beetle native to Asia.

In North America the borer is an invasive species, highly destructive to ash trees in its introduced range. The damage of this insect rivals that of Chestnut blight and Dutch Elm Disease. To put its damage in perspective the number of chestnuts killed by the Chestnut Blight was around 3.5 billion chestnut trees while there are 3.5 billion ash trees in Ohio alone. Dutch Elm Disease killed only a mere 200 million elm trees while EAB threatens 7.5 billion ash trees in the United States. The insect threatens the entire North American Fraxinus genus, while past invasive tree pests have only threatened a single species within a genus. Since its accidental introduction into the United States and Canada in the 1990s, and its subsequent detection in 2002 , it has spread to 14 states and adjacent parts of Canada. It has killed at least 50 - 100 million ash trees so far and threatens to kill most of the ash trees throughout North America. The green ash and the black ash trees are preferred. White ash is also killed rapidly, but usually only after green and black ash trees are eliminated. Blue ash displays some resistance to the emerald ash borer by forming callous tissue around EAB galleries; however, they are usually killed eventually as well.

Biology

Underside of Agrilus planipennis

The adult beetle is dark metallic green, bullet-shaped and about 8.5 mm 2 long and 1.6 mm (Template:Frac in) wide. The body is narrow and elongated, and the head is flat with black eyes. The larvae are approximately 1 mm (Template:Frac in) diameter, 26 to 32 mm long, and are a creamy white color. The eggs turn to a yellow brown color prior to hatching. Adults lay eggs in crevasses in the bark. Larvae burrow into the bark after hatching and consume the cambium and phloem, effectively girdling the tree and causing death within two years. The average emerging season for the emerald ash borer is early spring to late summer. Females lay around 75 eggs, but up to 300 from early May to mid-July. The borer's life cycle is estimated to be one year in southern Michigan but may be up to two years in colder regions.

A purple trap used for determining the extent of the invasion. This one hangs in Vanderburgh County, Indiana, near Darmstadt.

Distribution and dates of detection

The natural range of the emerald ash borer is eastern Russia, northern China, Japan, and Korea.

Its first confirmed North American detection was in June 2002 in Canton, Michigan. It is suspected, that it was introduced by overseas shipping containers being delivered to Yazaki North America. It has since been found in several other parts of the United States and Canada. Ohio, Minnesota, and Ontario have experienced emerald ash borer migration from Michigan. Additionally, Maryland and Virginia received shipments of contaminated trees from a Michigan nursery. The emerald ash borer was confirmed in Indiana in April 2004, in Central Kentucky in the Spring of 2009 and in Northeast Iowa in May 2010.

USDA APHIS PPQ used to attempt eradication of the insect, but its distribution is far too broad at this time and funds are lacking. Quarantine zones are still set up from which unprocessed raw hardwood material cannot be removed. The quarantine applies not only to the counties where the emerald ash borer has been detected but also high risk counties as well. The infected states have prohibited the movement of firewood from one state to another trying to eliminate the spread and fully enforce the quarantine zone. Large fines were imposed on a few companies that violated the ban, including one that was transplanting ash trees from southeast Michigan to Virginia and Maryland and is believed to be responsible for spreading the beetle to those states. The USDA has spent several hundreds of millions of dollars trying to minimize the ecological impact of EAB.

Michigan officials announced 2005-09-14 that ash borer infestation had crossed the Straits of Mackinac and was now in the Upper Peninsula for the first time. Wisconsin environmental officials consider it a grave threat and began preparations years ago for surveys in the state. Several counties in Indiana are under quarantine. However, states and cities are running out of money to combat the problem and many authorities feel that the borer will spread throughout North America. The EAB can move short distances by flying as well as surviving long distances in transit on ash tree nursery stock, Ash logs, branches, and firewood.

In June 2006, it was reported that emerald ash borers had been found at a home near Lily Lake, Illinois. Illinois officials have regulated several counties because it was found to be widespread. In July, 2006, further infestations were discovered in northern Cook County, Illinois, including Wilmette, Evanston, and Winnetka.

In June 2007, it was reported that emerald ash borers have been found in Cranberry Township, a suburb of Pittsburgh, Pennsylvania. On June 27, 2008, The Pittsburgh Post Gazette reported that the state Department of Agriculture says the emerald ash borer has been found in Mercer County. The invasive beetle was discovered in Butler and Allegheny counties last summer. Officials are surveying this year to gauge whether the insect has spread. Mercer joins Allegheny, Beaver, Butler and Lawrence counties in a quarantine prohibiting the movement of ash nursery stocks, green lumber and firewood.

In October 2007, an emerald ash borer larva was discovered in a West Virginia Department of Agriculture "detection tree" located in Fayette County. This detection tree was located in a recreational site, with camping, mountain biking, and white water rafting. It is believed that the pest arrived in firewood that was illegally transported by tourists visiting the New River Gorge area, a popular site for white water rafting (USDA-APHIS-PPQ).

As of December 2007, a federal quarantine has been imposed on the following areas in the U. S. for Emerald Ash Borer: the lower peninsula of Michigan; Mackinac County, Michigan; the entire states of Ohio, Illinois, and Indiana; Prince Georges County, Maryland; and Fayette County, West Virginia. (USDA-APHIS)

Emerald Ash Borer has also extended its distribution in Canada. As of August 2009, the following areas are regulated by the CFIA in Ontario: Essex, Lambton, Middlesex, Elgin, Huron, and Norfolk Counties, the Municipality of Chatham-Kent, the Cities of Hamilton and Toronto and the Regional Municipalities of Durham, York, Peel and Halton, the City of Sault Ste. Marie, and the City of Ottawa; in Quebec: The City of Gatineau and Municipalities of Carignan, Chambly, Richelieu, Saint-Basile-le-Grand and Saint-Mathias-sur-Richelieu.

By June 2008, emerald ash borers were discovered in the city of Chicago, and in the far south-west corner of Naperville.

It was confirmed by Canadian Agriculture officials to be present in Monteregie, Quebec. This region lies directly north of New England, therefore drastically increasing the likelihood of being found in New England.

On Tuesday, July 29, 2008, it was announced that the Missouri Department of Agriculture has detected the emerald ash borer in the state. On Monday, August 4, Wisconsin confirmed that the first appearance in the state was detected in the village of Newburg, Wisconsin, in Ozaukee County.

On March 11, 2009 it was confirmed in Mifflin County, Pa. This county lies in the Eastern Central part of the state.

The insect was furthermore detected in Victory, Wisconsin by agricultural officials on Tuesday April 7, 2009. This town is in the western part of the state, and borders Iowa and Minnesota. It is also along the Mississippi River, which may serve as a pathway for the insect.

On May 14, 2009, spread of the emerald ash borer was confirmed by the Minnesota Department of Agriculture in St. Paul, Minnesota. This represents the most westerly location it has been found thus far in North America.

The New York State Department of Environmental Conservation announced on June 17, 2009 that the emerald ash borer was recently discovered for the first time within the borders of New York State, in the Cattaraugus County town of Randolph.

Authorities across the US are continuing to determine the exact extent of EAB by placing purple traps nationwide.

Environmental and economic impact

A green ash killed by emerald ash borers

Evidence of the emerald ash borer sometimes takes up to a year to recognize. Some signs that the emerald ash borer has infested a tree are D–shaped holes in the bark of the trunk or branches and shoots growing from the base of the tree.

The beetle kills trees because the feeding larvae damage both the phloem (responsible for nutrient transport throughout the tree) and xylem (responsible for take-up of water and nutrients) tissues of the tree. The beetle effectively girdles the tree. One telltale sign of infestation is the presence of new 'sprouts' at the base of the tree's trunk. As long as the beetle does not eat into the bark at the very base of the tree, these sprouts can still get nutrients to grow and can continue to grow even after the main trunk is cut down. Unfortunately, once these sprouts reach one inch in diameter, they then become attractive targets for the EAB.

The insect is unusually difficult to kill. More than 7.5 billion ash trees are currently at risk. Nearly 114 million board feet (33,000 m³) of ash saw timber with a value of US$25.1 billion is grown in the eastern United States each year. Over forty million ash trees have died or are dying in the United States at this time. The full time it takes for a tree to die due to the EAB is generally two or three years.

The Emerald Ash Borer has killed nearly 30 million ash trees. Losses are estimated in the tens of millions of dollars.

The National Ash Seed Collection Initiative collects and stores ash seeds in cryogenic vaults at the National Center for Genetic Resources Preservation in Fort Collins, CO. If the population of American ash trees is destroyed, the stored seeds will be the genetic base to re-establish ash.

A pilot study is being undertaken in Michigan to determine if three different parasitic wasps can deter the emerald ash borer. These tiny stingless wasps can sense beetles underneath the bark and then lay their eggs in the larvae or egg, thus killing them. There have been doubts as to whether this biological control program will work, due to the fact that North American ash trees perish rapidly to the borer when they are planted in Asia, even where the parasitoids are present. It is not known at this time whether their release will have any unintended ecological impacts.The wasps have been released according to a Michigan newspaper. The releases began in July 2007, a few weeks later than they had hoped. (modification: USDA-APHIS-PPQ)

Effective steps to help reduce infestations and impact

• Purchase firewood at or near the campsite
• Do not bring firewood back to destination after a camping trip
• Inspect firewood. Make sure it has no bark at all or signs of infestation
• Treat already infested trees or prevent future infestation[1]
• Know the signs and symptoms of the borer. The quicker its detected, the better the chance of eradication.
• If you have Ash Trees in your landscape or woodlot and desire to keep them alive, consult a State-Certified Horticulturalist for treatment options. Direct-Injections to the cambial layer (soft inner bark) have proven effective.

External links

• Canadian Food Inspection Agency
• Multistate EAB website
• "Emerald ash borer". United States Department of Agriculture.
• Southeast Michigan Resource Conservation & Development Council - Ash Utilization Options Project - developing value-added products from ash trees affected by the emerald ash borer
• Emerald ash borer Indiana Information
• Canadian Food Inspection Agency
• Ontario Ministry of Natural Resources
• Ohio Department of Natural Resources page on EAB
• Ohio Department of Agriculture infestation PDF map
• Wisconsin's Emerald Ash Borer Information Source
• [2]