By Mark Shour
Iowa State University
Tornadoes at Parkersburg and Little Sioux Boy Scout Camp… flooding in Burlington, Cedar Rapids, Charles City, Elkader, Iowa City, Muscatine, Waterloo and adjacent areas… Iowa was hard-hit in 2008 with natural disasters. Many reading this article received calls from friends and relatives asking if they were affected by these situations. Some news stories last year in our state were terrible.
In contrast, reports on how Iowans responded to these situations were exemplary. Neighbors helping neighbors… Iowa National Guard units assisting at several locations… people of all ages and from various places reaching out to others needing a helping hand. Yes, Iowans listen to news media and act appropriately.
Such is the case with the educational outreach on the emerald ash borer, Agrilus planipennis. The news media have done several stories on this destructive, exotic beetle from Asia in the past five years and Iowans are doing their part. Collaborative partners (Iowa Department of Agriculture and Land Stewardship, Iowa Department of Natural Resources, USDA APHIS Plant Protection Quarantine, and Iowa State University Extension) have received hundreds of telephone calls and emails asking for more information about this pest or to report suspect ash trees.
Private land owners, park officials, municipal workers and others have permitted the collaborative partners access to their ash trees for emerald ash borer (EAB) monitoring activities. Arborist groups, garden clubs, city plant boards, colleges/universities and public works organizations have held special meetings to discuss EAB and its potential impact on Iowa.
The emerald ash borer is a small dark metallic green beetle, about as long as Mr. Lincoln’s image on a penny. Adult beetles produce minor feeding damage to ash leaflets, but it is the flat, white, legless larval stage that kills ash trees by cutting through the plant’s internal plumbing just beneath the bark. Trees affected display various symptoms including the thinning/dieback of branches in the crown, water sprouts (epicormic shoots) along the trunk and major branches, “D-shaped” exit holes cut through bark and extensive woodpecker feeding on the tree.
This pest was first discovered in Detroit, Mich., in 2002. Unknowingly, people have transported EAB into Illinois, Indiana, Maryland, Missouri, Ohio, Pennsylvania, Virginia, Wisconsin and West Virginia by moving infested firewood, landscape trees and other ash wood products. The U.S. Department of Agriculture has placed these states under quarantine in an effort to slow the spread of this insect.
2008 Monitoring Results
Collaborative partners worked on three fronts in searching for EAB: visual surveys, sentinel trees and experimental traps. A total of 235 campgrounds (private, county, state and federal) in 55 counties were identified as high risk sites and 1,269 ash trees were visually inspected. Although the number of sites was less than in 2007, the flooding episodes prevented access to many campgrounds in 2008.
Sentinel trees (containerized ash trees or girdled standing ash trees) were established across Iowa. A total of 401 trees (129 containerized and 272 standing trees) were bark peeled during the fall/early winter of 2008.
Iowa participated in two types of survey efforts using the large purple sticky traps provided by USDA APHIS PPQ. The national survey effort placed 192 traps in ash trees in 30 counties; these were high risk sites such as campgrounds. A delimiting survey was set up in extreme eastern Iowa (Dubuque, Jackson, Clinton, Cedar, Scott, Muscatine, Louisa and Des Moines counties) on a 1.5 mile x 1.5 mile grid. A total of 452 purple traps were used for this survey.
Fortunately, no survey effort discovered EAB in Iowa during 2008. This does not mean that the insect is not present in the state, but there is a decreased likelihood that EAB has established here.
Plans for 2009
We have an excellent opportunity to be prepared ahead of the invasion of EAB. Things that can be done to help Iowa prepare are:
- ASSIST collaborative partners in their survey efforts by permitting access to property
- VOLUNTEER to help your community develop a tree inventory
- PROTECT your trees from mechanical injuries; WATER during dry periods
- REPORT suspect ash trees or beetles to ISU Extension Entomology (515) 294-1101 or the State Entomologist (515) 725-1470
- TALK with city managers, county officials, state legislators, and U.S. congressional members. Ask them if EAB preventive efforts are included in fiscal budgets
- ENCOURAGE local firewood purchases when friends or relatives come to Iowa for camping, fishing or hunting.
- RESIST the urge to apply a preventive insecticide at this time, since EAB is not known to be in Iowa
- KEEP INFORMED through ISU Extension offices and specific Web sites, www.extension.iastate.edu/pme/EmeraldAshBorer.html or www.emeraldashborer.info/ .