{"id":22174,"date":"2023-05-12T10:37:26","date_gmt":"2023-05-12T14:37:26","guid":{"rendered":"https:\/\/www.purdue.edu\/fnr\/extension\/?p=22174"},"modified":"2026-04-01T10:46:25","modified_gmt":"2026-04-01T14:46:25","slug":"should-ash-trees-still-be-protected-from-eab","status":"publish","type":"post","link":"https:\/\/www.purdue.edu\/fnr\/extension\/should-ash-trees-still-be-protected-from-eab\/","title":{"rendered":"Should Ash Trees Still be Protected From Emerald Ash Borer?"},"content":{"rendered":"<p><a title=\"Purdue Landscape Report\" href=\"https:\/\/www.purduelandscapereport.org\/article\/should-ash-trees-still-be-protected-from-emerald-ash-borer\/\" target=\"_blank\" rel=\"noopener\">Purdue Landscape Report<\/a>: The emerald ash borer (EAB),\u00a0<em>Agrilus planipennis,<\/em>\u00a0is still one of the most damaging insect pests ever to invade North American forests. Unlike most native boring insects, this beetle can attack and kill relatively healthy ash trees. In Indiana cities we found this insect capable of killing most of the unprotected ash trees within 6 to 10 years.\u00a0 Nearly 20 years after its first detection in Indiana (2004), trees still need to be protected to keep them alive. The benefits of these living ash trees easily justify the cost of monitoring them. We provide answers to common questions people have about the need for continued treatment.<\/p>\n<ul>\n<li><em>I have had a tree care specialist treat my ash trees for the last 10 years. What will happen to these trees if I stop this service?<\/em>\u00a0If your trees are still healthy, they were probably treated with injections of emamectin benzoate.\u00a0 Initially we recommended treating trees once every 2 years. This was especially helpful during the initial invasion when each newly infested tree was producing hundreds of beetles per year.\u00a0 Now that most of the untreated ash trees are dead in Indiana, there are fewer emerald ash borers to attack the surviving ash trees. Research clearly shows that treating trees once every 3 years is enough to keep ash trees alive. Increasing the time between treatments beyond 3 years will increase the risk of losing your trees.<a href=\"https:\/\/www.purdue.edu\/fnr\/extension\/wp-content\/uploads\/2015\/02\/Mountain-ash-and-the-sky-e1565284919429.jpg\" data-rel=\"lightbox-image-0\" data-rl_title=\"ash tree\" data-rl_caption=\"ash tree\" title=\"ash tree\"><img loading=\"lazy\" decoding=\"async\" class=\"size-thumbnail wp-image-12334 alignright\" src=\"https:\/\/www.purdue.edu\/fnr\/extension\/wp-content\/uploads\/2015\/02\/Mountain-ash-and-the-sky-150x150.jpg\" alt=\"ash tree\" width=\"150\" height=\"150\" \/><\/a><\/li>\n<\/ul>\n<p>We recently completed a 10-year study in Indianapolis, where large ash trees were treated at 3-year intervals (2013 and 2016), Although they were well-protected through 2019, we saw a slight increase in damage 4 and 5 years after the last injection (2020 and 2021).\u00a0 By the 6<sup>th<\/sup>\u00a0year trees after the last treatment (2022), trees declined to the point that they were a safety hazard.\u00a0 Overall, spring treatments were more effective than fall treatments.<\/p>\n<ul>\n<li><em>Is it worthwhile to continue treating my trees?\u00a0<\/em>The simple answer is YES, especially if you think about the costs of the alternatives over time. Consider the following choices:\n<ul>\n<li><em>Homeowner tree removal vs treatment.\u00a0<\/em>Suppose you had ash tree that was whose trunk diameter was 30 inches. If you were to have that tree and its stump removed, the cost could easily be $1800.\u00a0\u00a0 If an ash tree is near your house or other valuable structure special precautions need to be taken to keep limbs from causing damage. These protective measures add greatly to the labor costs and could easily double the removal costs ($3600). In contrast, to keep that tree alive, you would have to inject that tree once every three years at a cost of $300 (assuming the fee is $10\/ diameter inch).\u00a0 In other words, the $1800 -3600 you pay to remove the trees would provide 18-36 years of enjoying your tree!<\/li>\n<li><em>Homeowner tree replacement vs treatment.<\/em>\u00a0Trees grow slowly. Most add a bit less than a half an inch per year of diameter to the trunk. So, if you add $500 on top of the removal costs to plant a new tree ($2300- $4100), the same money would provide 23 to 42 years of tree enjoyment. Moreover, the tree you planted would only be half the size of the original ash tree in 30 years.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>For the full article please visit Purdue Landscape Report: <a href=\"https:\/\/www.purduelandscapereport.org\/article\/should-ash-trees-still-be-protected-from-emerald-ash-borer\/\" target=\"_blank\" rel=\"noopener\">Should ash trees still be protected from emerald ash borer?<\/a><\/p>\n<p><strong>Resources:<br \/>\n<\/strong><a href=\"https:\/\/www.purdue.edu\/fnr\/extension\/new-hope-for-fighting-ash-borer\/\">New Hope for Fighting Ash Borer<\/a>, Got Nature? Purdue Extension-FNR<br \/>\n<a href=\"https:\/\/www.purdue.edu\/fnr\/extension\/invasive-pest-species-managing-emerald-ash-borer-in-the-urban-forest\/\" target=\"_blank\" rel=\"noopener noreferrer\">Invasive Pest Species: Tools for Staging and Managing EAB in the Urban Forest<\/a>, Got Nature?<br \/>\n<a href=\"https:\/\/extension.entm.purdue.edu\/EAB\/\" target=\"_blank\" rel=\"noopener noreferrer\">Emerald Ash Borer<\/a>, Purdue Extension-Entomology<br \/>\n<a href=\"https:\/\/extension.entm.purdue.edu\/EAB\/Tools.html\">Emerald Ash Borer Tools &amp; Resources<\/a>\u00a0\u2013 Purdue Extension Entomology<br \/>\n<a href=\"https:\/\/youtu.be\/iIaYvtqY7-I\">Planting Your Tree Part 1: Choosing Your Tree<\/a>, Purdue Extension YouTube Channel<br \/>\n<a href=\"https:\/\/youtu.be\/k5rUgd7BmiA\">Tree Planting Part 2: Planting a Tree<\/a>, Purdue Extension &#8211; Forestry and Natural Resources YouTube Channel<br \/>\n<a href=\"https:\/\/www.entm.purdue.edu\/iisc\/invasiveplants.php\">Indiana Invasive Plant List,<\/a> Indiana Invasive Species Council, Purdue Entomology<br \/>\n<a href=\"https:\/\/www.purdue.edu\/fnr\/extension\/landscape-report-shares-importance-of-soil-testing\/\">Landscape Report Shares Importance of Soil Testing,<\/a> Purdue FNR Extension<br \/>\n<a href=\"https:\/\/youtu.be\/pDsL_78Pdi8\" target=\"_blank\" rel=\"noopener\">Find an Arborist<\/a> website, Trees are Good, International Society of Arboriculture (ISA)<br \/>\n<a title=\"Tree Risk Management\" href=\"https:\/\/www.extension.purdue.edu\/extmedia\/FNR\/FNR-475-W.pdf\" target=\"_blank\" rel=\"noopener\">Tree Risk Management<\/a> \u2013 The Education Store, Purdue Extension&#8217;s resource center<\/p>\n<p><a href=\"https:\/\/extension.entm.purdue.edu\/staff.html\" target=\"_blank\" rel=\"noopener\">Bob Bruner<\/a>, Exotic Forest Pest Educator<br \/>\nPurdue Entomology<\/p>\n<p><a href=\"https:\/\/extension.entm.purdue.edu\/staff.html\" target=\"_blank\" rel=\"noopener\">Cliff Sadof<\/a>, Professor, Ornamental, Pest Management<br \/>\nPurdue Entomology Extension Coordinator<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Purdue Landscape Report: The emerald ash borer (EAB),\u00a0Agrilus planipennis,\u00a0is still one of the most damaging insect pests ever to invade North American forests. Unlike most native boring insects, this beetle can attack and kill relatively healthy ash trees. In Indiana cities we found this insect capable of killing most of the unprotected ash trees within [&hellip;]<\/p>\n","protected":false},"author":58,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[80,47,53],"tags":[330,507,65,67,408,72,1113],"class_list":["post-22174","post","type-post","status-publish","format-standard","hentry","category-trees","category-invasiveinsects","category-urbanforestry","tag-emerald-ash-borer","tag-forest","tag-invasive-insects","tag-plants","tag-trees","tag-wildlife","tag-woodland","audience-for-enthusiasts","audience-for-homeowners","audience-for-landowners","audience-for-professionals"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.purdue.edu\/fnr\/extension\/wp-json\/wp\/v2\/posts\/22174","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.purdue.edu\/fnr\/extension\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.purdue.edu\/fnr\/extension\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.purdue.edu\/fnr\/extension\/wp-json\/wp\/v2\/users\/58"}],"replies":[{"embeddable":true,"href":"https:\/\/www.purdue.edu\/fnr\/extension\/wp-json\/wp\/v2\/comments?post=22174"}],"version-history":[{"count":14,"href":"https:\/\/www.purdue.edu\/fnr\/extension\/wp-json\/wp\/v2\/posts\/22174\/revisions"}],"predecessor-version":[{"id":41124,"href":"https:\/\/www.purdue.edu\/fnr\/extension\/wp-json\/wp\/v2\/posts\/22174\/revisions\/41124"}],"wp:attachment":[{"href":"https:\/\/www.purdue.edu\/fnr\/extension\/wp-json\/wp\/v2\/media?parent=22174"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.purdue.edu\/fnr\/extension\/wp-json\/wp\/v2\/categories?post=22174"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.purdue.edu\/fnr\/extension\/wp-json\/wp\/v2\/tags?post=22174"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}