Issue 2, April 30, 2012

Emerald Ash Borer

Emerald ash borer should be flying in both central and southern Illinois and will continue to emerge and fly for several weeks. Although insecticide sprays against the adults are effective, applications of systemic insecticides between 50% leaf expansion in spring until approximately six weeks before leaf fall are recommended. Emerald ash borer adults feed on ash leaflets, and it is probably during this activity that sprayed insecticide is ingested resulting in beetle mortality. Systemic insecticides kill the beetles in this manner, but also kill the larvae in the cambium area under the proper application rates. Systemic insecticides applied to the soil or injected into the tree reach the leaves within a week or two. Trunk injections reach effective levels in the cambium area in about two weeks; whereas soil applications take about six weeks. Additional information on emerald ash borer including our management recommendations can be found on-line. (Phil Nixon)

Phil Nixon

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