Total Landscape Care Digital Magazine
Issue link: http://read.dmtmag.com/i/132471
chemical care do the most damage by feeding on the inner bark of ash trees, disrupting the trees ability to transport nutrients and water. Conservative estimates for costs associated with treating EAB or removing/replacing trees are staggering. "Annually, cities are spending $850 million a year to deal with this," McCullough says. "Private households are spending $350 million per year, plus they are sustaining a decrease in the property borers are "Emerald ash building too good at their populations. Total eradication is just not an objective anymore. " value of their homes of about $380 million. So if you want to start adding it up, these costs are easily in the billions every year — and that's lowballing it. This doesn't even include the ecological impact, which is harder to put a dollar on." In 2009, McCullough partnered with other researchers to determine, in dollars, how costly EAB will be during the next decade, given the conservative spread of the pest and looking at landscape trees only in urban areas. "We projected costs for either treating every two years or replacing ash trees with something other than ash. By 2019, the PHOTO: DAVID CAPPAERT, MICHIGAN STATE UNIVERSITY, BUGWOOD.ORG SYMPTOMS OF EMERALD ASH BORER • • • • Dieback of tree canopy New sprouts forming from the tree's base D-shaped exit holes Woodpecker damage Source: New York Invasive Species 5 0 To ta l L a n d s cap eCare.c om TLC0613_ChemCare.indd 50 costs would be more than $10 billion — and that's with us underestimating the spread," McCullough says. Close encounters Gaps in the spread of EAB prove humans are helping these beetles get a little farther down the road. Left to their own devices, they would spread slowly. Transportation of firewood has been blamed as the main method of progression. "Most of these new infestations are not necessarily that beetles are spreading naturally, but it's human transport — and most infestations are in the fourth generation before they are discovered," McCullough says. Detecting beetles, especially in places they have never been, is more challenging than ridding them from trees. "We hardly ever know when a tree first becomes infested," McCullough says. "You would never know unless you peeled the bark off the trees because trees are tolerant of first and second generations, but by the third and fourth generations, you're going to see the symptoms, and by then it could be too late." Knowing if treatments will work depends on how damaged the tree is when you first notice symptoms. If more than half of the canopy is dying, no amount of treatment will bring the tree back. McCullough says, in addition to checking regularly for things like woodpecker holes (a clue beetle larvae could be present) and new sprouts on the base of the tree, actively tracking the spread of EAB is your best bet for saving trees. Current maps of known EAB populations can be found at emeraldashborer.info. If EAB have been detected within 15 miles of your client, it's time to figure out how you'll deal with it. "If you can be proactive and decide what you're going to do with these ash trees ahead of time, you won't have to react," McCullough says. If your plan involves treating trees instead of replacing them, you can choose from many products that are labeled for controlling EAB. These products can effectively protect trees from EAB. J U N E 2 013 5/23/13 3:51 PM