Tree-killing Pest Found in Third County in Iowa

Tree-killing Pest Found in Third County in Iowa

Emerald Ash Borer has killed millions of trees in North America; it's now been found in three counties in Iowa by the Iowa Department of Agriculture.

Emerald Ash Borer has been positively identified in a residential tree in the city of Fairfield in Jefferson County, making this the third location where the invasive beetle has been found in Iowa. Allamakee County in northeast Iowa was declared infested in May 2010 and Des Moines County in southeast Iowa was declared infested in July 2013. This latest discovery was announced last week by the Iowa Department of Agriculture.

Emerald Ash Borer kills all ash trees and is considered to be one of the most destructive tree pests ever seen in North America.

DESTRUCTIVE INSECT: Emerald Ash Borer has been positively identified in a residential tree in the city of Fairfield in Jefferson County in southeast Iowa. This discovery, announced last week, is the third location where the invasive beetle has been found in Iowa. The insect is a small, metallic-green beetle native to Asia. Its larvae burrow into the bark of ash trees, causing the trees to starve and eventually die.

With this latest find in Jefferson County being close to the nearby Des Moines County infestation which was discovered last month, state and federal officials will issue a multi-county quarantine in southeast Iowa in the near future. The quarantine will limit the movement of hardwood firewood, ash logs and wood chips. "This regulatory action will restrict the movement of firewood, ash logs and wood chips out of the quarantined counties," says Robin Pruisner, state entomologist at the Iowa Department of Agriculture & Land Stewardship.

State ag officials are issuing a multi-county quarantine in southeast Iowa

Pruisner says all Iowans are strongly cautioned not to transport firewood across county or state lines, since the movement of firewood throughout Iowa or to other states poses the greatest threat to quickly spread the pest even further. Most Emerald Ash Borer infestations in the United States have been started by people unknowingly moving infested firewood, nursery plants or sawmill logs. The adult beetle also can fly short distances, approximately two to five miles.

The current ash borer infestation was found as a result of survey efforts by the Iowa EAB Team. This team includes officials from the Iowa Department of Agriculture, Iowa State University Extension, Iowa Department of Natural Resources, USDA Animal Plant Health Inspection Service and the USDA Forest Service.~~~PAGE_BREAK_HERE~~~

Can you spray an insecticide to kill this insect? "Preventive treatments next spring — mid-April to mid-May 2014 — are suggested to protect vigorously healthy and valuable ash trees within 15 miles of the known infested area," says ISU Extension entomologist Mark Shour. For more details, see ISU Extension publication PM2084.

Iowa has an estimated 52 million rural ash trees and 3 million ash trees in urban areas

Ash is one of the most abundant native tree species in North America, and has been heavily planted as a landscape tree in yards and other urban areas. According to the USDA Forest Service, Iowa has an estimated 52 million rural ash trees and approximately 3.1 million more ash trees in urban areas. It is unknown how many public and residential ash trees are located in Fairfield.

To learn more about EAB and other pests that are threatening Iowa's tree population, visit the IDALS website. Or, for more information contact any of the following members of the Iowa EAB Team:

* Robin Pruisner, State Entomologist, 515-725-1470, [email protected]

* Tivon Feeley, DNR Forest Health Coordinator, 515-281-4915, [email protected]

* Emma Hanigan, DNR Urban Forest Coordinator, 515-281-5600, [email protected]

* Jesse Randall, ISU Extension Forester, 515-294-1168, [email protected]

* Mark Shour, ISU Extension Entomologist, 515-294-5963, [email protected]

* Laura Jesse, ISU Extension Entomologist, ISU Plant and Insect Diagnostic Clinic, 515-294-0581, [email protected]

* Donald Lewis, ISU Extension Entomologist, 515-294-1101, [email protected].

* Jeff Iles, ISU Extension Horticulturist, 515-294-3718, [email protected]

Frequently Questions/Answers on Emerald Ash Borer (EAB) Fairfield, Iowa

What is the emerald ash borer?  It is a very small, shiny green beetle (½ inch long x ? inch wide; about the size of Mr. Lincoln's image on a penny).

What does EAB eat?  Hosts are species (and cultivars) of ash in the genus Fraxinus.  Hosts include green ash (e.g., 'Marshall Seedless', 'Patmore', and 'Summit'), white ash (e.g., Autumn Purple), black ash, blue ash, and pumpkin ash. Manchurian and Chinese ash trees are primary hosts in its homeland [Eurasia].  Mountain ashes (Sorbus species) are NOT hosts.

Where is EAB from?  This beetle is native to Asia and is found in China and Korea. It also has been reported in Japan, Mongolia, the Russian Far East, and Taiwan. EAB arrived in the United States sometime before 2002 in wood packing materials.~~~PAGE_BREAK_HERE~~~

How did it get to Fairfield, Iowa? Most EAB infestations in the United States have been started by people unknowingly moving infested firewood, nursery plants, or sawmill logs. The adult beetle also can fly short distances (two to five miles).

Should I be concerned about EAB?  Yes. It kills ash trees, usually in two to four years. In the Midwest, millions of ash trees have been killed by EAB since 2002. It is unknown how many public and residential ash trees are located in Fairfield.

How do I know if I have an ash tree in my yard?  Check on tree identification at the Extension online store and the Extension website.

How do I know if my tree is infested?  Look for the following symptoms:

Thinning or dying branches in the top of the tree

Water sprouts (suckers) halfway up the trunk

Feeding notches on edge of leaflets

Woodpecker feeding sites/many bark flakes on lawn

S-shaped feeding galleries under bark

D-shaped exit holes (1/8 inch diameter)

Who can help me determine if my tree is infested?  Local authorities you can contact if you suspect EAB in your tree:

City of Fairfield Parks 641-472-2693

Iowa DNR Forester 641-471-2370

Jefferson County Extension Office 641-472-4166

Who should be thinking about treating ash trees?  If you are a homeowner within 15 miles of Fairfield you can evaluate the health of your tree, and if it is healthy you can consider treatment next year. If you are not in a known infested area, we do not recommend treatment at this time. 

Ash borer management options 

Ash trees can be protected with insecticide applied by a commercial pesticide applicator or the homeowner. Trees must be healthy, vigorously growing, and valuable to your landscape. 

Most of the treatments must be done each year for the life of the tree. Treatment may not be effective due to past injuries to the tree, soil moisture, soil compaction, and other site and environmental factors.

Preventive treatments are most effective. Infested trees with less than 40% dieback of the crown might be saved.~~~PAGE_BREAK_HERE~~~

Preventive treatments for EAB are NOT recommended until a confirmed EAB site is 15 miles away. Treatment outside this risk zone is not prudent. 

Systemic insecticides require time and active tree growth for distribution in the ash tree. Most products must be applied in early spring to be effective. An additional fall treatment may be required for larger trees.

Canopy sprays are NOT recommended by ISU Extension and Outreach because of limited effectiveness, the need for specialized equipment, spray drift, and possible adverse effects to nontarget organisms.

If I am contacted by a pesticide applicator to treat ash trees for EAB at this time, what course should I take?  Mid- to late summer is TOO LATE to apply a treatment. Next spring (mid-April to mid-May), IF you live within 15 miles of a confirmed EAB infested site, get an estimate for the treatment. Try to obtain at least one additional estimate before any work is done. IF you live outside the risk zone, thank the applicator for showing interest and keep the company information on file. 

Where else has EAB been found in Iowa?  Three counties have been identified as having EAB infestations: 

Allamakee – The northeast Iowa infestations have been found in New Albin and Lansing, Iowa, as well as at Black Hawk Point and Plough Slough wildlife areas.

Des Moines – One urban tree in Burlington was identified as EAB infested on July 10. 

Jefferson – One urban tree in Fairfield was identified as EAB infested in late July 2013

Now that EAB has come to Iowa, is there some plan to manage/contain this pest?  Yes, a detailed plan has been developed by collaborative agencies. This plan provides the stepwise actions to be taken to contain the pest, and the agencies responsible for the various anticipated actions. The EAB Response Plan and other current Iowa information about EAB are given here.~~~PAGE_BREAK_HERE~~~

What does the EAB quarantine mean? A quarantine by state and U.S. agriculture departments means that hardwood firewood, ash logs, and wood chips cannot be moved out of the area without a permit. Homeowners must not remove their ash tree or firewood from their tree to an area outside the quarantine. Tree removal companies must not haul logs or firewood outside the quarantine area unless inspected and treated as required by the regulations. For more information on how a quarantine will impact your business, contact USDA at 515-251-4083 if moving wood products outside of Iowa, and IDALS at 515-725-1470 if moving wood products within Iowa.

What should a homeowner or tree care company do with ash trees cut down in or near the infested area?   At this time the preferred disposal method is to use the wood within the quarantined area. Plans are being developed for Fairfield/Jefferson County residents to dispose of wood waste (twigs, brush, limbs, and branches).

What general recommendations are available to communities?  The Iowa Department of Natural Resources – Forestry Bureau has worked with several communities to deal with EAB infestations.  Contact Tivon Feeley, 515-281-4915, or Emma Hanigan, 515-281-5600, for more information.

Where can I find current information about EAB on the Internet?  Sites to gather current information about this exotic pest include:

National site

ISU Extension and Outreach



TAGS: USDA Extension
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