2009-07-01 P & R Packet - Laserfiche WebLink

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Insecticide Options for Protecting Ash Trees from Emerald Ash Borer ~#:: ash borer (Agrilus p/an/pennis rmaire), an invasive insect native to ia, has killed tens of millions of ash rees in urban, rural and forested settings. This beetle was first discovered in 2002 in southeast Michigan and Windsor, Ontario. As of June 2009, emerald ash borer (EAS) infes- tations were known to be present in 12 states and two Canadian provinces. Many hom- eowners, arborists and tree care profession- als want to protect valuable ash trees from EAB. Scientists have learned much about this insect and methods to protect ash trees since 2002. This bulletin is designed to answer frequently asked questions and provide the most current information on insecticide options for controlling EAB. Answers to Frequently Asked Questions ,i) If you elect to treat your ash trees, there are several insecticide options available and research has shown that treatments can be effective. Keep in mind, however, that con- trolling insects that feed under the bark with insecticides has always been difficult. This is especially true with EAB because our native North American ash trees have little natural resistance to this pest. In university trials, some insecticide treatments were effective in Herms. McCullough, Smitley. Sadof. Williamson, Nixon some sites, but the same treat- ments failed in other sites. Further- more, in some studies conducted over multiple years, EAB densities continued to increase in individual trees despite annual treatment. Some arborists have combined treatments to increase the odds of success (e.g., combining a cover spray with a systemic treatment). Our understanding of how EAB can be managed successfully with insecticides has increased substantially in recent years. The current state of this understanding is detailed in the bulletin. It is important to note that research on management of EAB remains a work in progress. Scientists from universities, government agencies and com- panies continue to conduct intensive studies to understand how and when insecticide treatments will be most effective. . ", :)'./ :;'\\' 0' 1e:: ,! :'h ,[;:/'-\:-? h., "if(:ct,\/l; :l';;'::C:!''':i'::C - If a tree has lost more than 50 percent of its canopy, it is probably too late to save the tree. Studies have shown that it is best to begin using insecticides while ash trees are still relatively healthy. This is because most of the insecticides used for EAB control act systemically - the insecticide must be trans- ported within the tree. In other words, a tree must be healthy enough to carry a systemic ,