Debbie Blank
When the emerald ash borer arrived in the United States most probably from northeast China and crept out of a wooden shipping crate in Detroit in the early 1990s, “we let an enormous menacing child into a giant candy shop,” Jodie Ellis, a Purdue University entomologist who specializes in invasive forest pests, told about 20 at the Batesville Memorial Public Library Dec. 17.
The beetle was discovered in the United States in 2002. “This insect could wipe out ash as a species in North America,” she reported. “Unless ash trees are treated with pesticides, the mortality rate of (infected) trees is 100 percent.” About 6 percent of Hoosier forest trees are ashes.
In Asia, natural enemies attack EAB, but North American ash trees “have no inherent defense against an attack” by the borer, she noted.
Ripley County became the 21st in Indiana to have EAB confirmed after an Adams Township landowner called Purdue University in November. Experts estimated the pest has been here for at least two or three years.
Because it was found near the county line, “I would bet you it's in Franklin County as well,” Ellis said.
First the township was quarantined, then the county, which means regulated items cannot be moved out of Ripley County except to any contiguous counties also being quarantined. “Finally, the federal government comes in and says you can't move quarantined items out of the state.”
Quarantined items include the insect itself; all hardwood firewood, not just ash; ash dunnage with crating; ash nursery stock; ash lumber and wood with bark attached; entire ash trees; ash limbs and branches; and uncomposted ash chips greater than 1 inch in diameter.
Pine firewood is exempt because it can be easily distinguished from hardwood firewood and it cannot harbor EAB.
According to the entomologist, “we are seeing some promising results from the quarantine.” The infestation is spreading slower than it would be without controls.
“The fines for violating these quarantines can be severe, especially in federal cases ... it can cost you thousands of dollars” and in severe cases criminal charges could be filed.
How does the borer attack an ash tree? She explained, “Sometime in May the adults that have developed under the bark chew out onto the tree” and start feeding in the tree’s canopy. After the beetles mate, females lay eggs along the bark and tiny larvae immediately go through that layer and begin to feed inside – “in essence on the tree's vascular system.” Within one to three years, the tree dies.
Symptoms include a canopy’s decline; “witch's brooms” forming near the tree’s bottom below the dying portion; D-shaped exit holes, much smaller than quarters; very distinctive S-shaped feeding patterns beneath the bark; vertical splits in the bark; and heavy downy woodpecker activity (“they love EAB larvae”).
The federal government has devoted millions of dollars to pinpoint EAB locations to slow its spread, Ellis said. Leaders at the Indiana Department of Natural Resources and U.S. Department of Agriculture Animal Plant Health Inspection Services have worked cooperatively to place 3,125 purple traps bated with pheromones throughout the state.
On its own, a borer or its offspring will move just a half mile per year. With unwitting human help, EAB has been found as far from Detroit as Maryland, Kentucky and Minnesota. “We suspect the main culprits were firewood and nursery trees,” the speaker said.
One Purdue brochure notes, “Movement of infested firewood is the leading cause of EAB expansion and contributes to the spread of other insects and diseases.” The document instructs, “Do not bring firewood of any kind from home to a campground. Use local sources of firewood only. If you have already brought firewood from home, do not take it back home or leave it for other campers. Burn it!”
Because EAB has been found in Ripley County, "it's time to treat" ash trees, preferably next spring. Chemicals injected into trees or placed on the ground to be taken up by roots are best used as preventatives, rather than cures. Some treatments can be used by homeowners and others by licensed applicators.
EAB cannot be eradicated from large ash stands by pesticides sprayed from airplanes, she added.
Many posed questions. Frank LaGreca, Dillsboro, suggested the campsites at the National Muzzle Loading Rifle Association grounds in Friendship might be among the most vulnerable areas. “They bring in firewood like you can't believe” from as far away as Canada. Firewood is the single most difficult issue to handle, agreed Steve Krecik, Aurora, a USDA plant protection and quarantine officer who covers Ripley and 15 other counties. He has issued violation notices to travelers carrying firewood.
With much of the northeastern part of Indiana and now Ripley County infested, Staff Ripley, Dillsboro, questioned why the whole state isn’t quarantined. Ellis said EAB has been confirmed in seven southern counties within the last year, but so far EAB has not been detected in southwest Indiana. She admitted the entire state might be quarantined “someday ... but not quite yet.”
Dolores Pingsterhaus, Batesville, asked, “As homeowners, what can we do (to protect a) beautiful tree in our front yard? We planted it 20 years ago.” Ellis responded, “If you cannot find a tree care person who has the equipment and knowledge to do this, give me a call (at 765-494-0822) .... They have very good products.”
Tom Leising, who owns Leising Mulch in Decatur County, was concerned that he would no longer be able to accept ash materials from Ripley County. “Financially, is this going to affect me?” Ellis answered, “This may be a boon for you.”
“One of the compliance agreements is for chippers,” noted Marcus McDonough, Lafayette, formerly of Batesville, a DNR nursery inspector and compliance officer. “We ask that you don't move it between May 1-Aug. 15, the flight period. You said you grind it right away. That's one thing we do allow.” Ellis recommended Leising talk to DNR. “You do need to work with them to avoid heavy fines.”
LaGreca wondered, “Once we think we have it, what do we do?” McDonough said a DNR specialist could identify EAB. Jason Shorter, this area’s DNR nursery inspector and compliance supervisor, can be reached at 317-232-4120 or jshorter@dnr.IN.gov.
David Osborne, county extension director, also can answer questions and suggest resources at 812-689-6511. He is planning more educational workshops in 2010. Krecik can offer woodland owners approaches to slow EAB’s spread by calling him at 812-926-3781.
Ellis pointed out that because of the emerald ash borer infestation, shipping legislation now is much stricter. Port inspections emphasize examining wooden packing materials so in the future other pests may be stopped before they decimate a plant species.
She is hopeful scientists can catch up with this ash tree killer, finding better control methods, including natural enemies.
