University of Kentucky College of Agriculture


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This web page contains information about the emerald ash borer in Kentucky. Go to for regional and national information on this invasive insect. Report suspected EAB activity outside of the known area of infestation to the Office of the State Entomologist - (859) 257-5838.

State-wide EAB Quarantine Issued

Effective immediately, (April 3, 2014) the Animal and Plant Health Inspection Service (APHIS) is expanding the list of regulated areas for the emerald ash borer (EAB) to include the entire Commonwealth of Kentucky. APHIS is taking this action in response to the detection of EAB in widely separated locations in Kentucky. APHIS previously regulated only a portion of Kentucky due to the establishment and enforcement of equivalent state quarantines. Kentucky, however, has rescinded its EAB quarantine, so APHIS is adding all of Kentucky to the APHIS list of regulated areas to prevent the spread of EAB to other states. Here is the text of the quarantine order.

Ky EAB Distribution 2014

Green identifies the counties that were quarantined before the statewide order in 2014. It does not mean that the insects are present thooughout these counties and in some cases the borer was not found but was present in surrounding counties. The newest confirmations of EAB in Kentucky (2013) are Bourbon, Carroll and Whitley counties.

EAB thoughts for 2014

Quarantine regulations for the emerald ash borer now include the entire state. This Federal Order directly affects the wood and nursery industries because it regulates the interstate movement of ash nursery stock, green lumber, waste, compost, and chips of ash species, and firewood of all hardwood species. While it is quite likely that the insect is present outside the original green quarantine counties (map above), the entire state is not infested at this time. EAB activity is still very localized within some of those counties.

Consequently, there are some important things to keep in mind:

  1. The greatest potential for infestation occurs in the counties pictured in green. Homeowners living within those counties or within 15 miles of known infestations who wish to protect their ash trees should start or continue to apply protective treatments. You can get information on effective control options for the EAB from your local Cooperative Extension Office. At this point, it is not clear how long ash trees must be protected while the wave of EAB infestation passes through but 7 to 10 years is a reasonable estimate. This decision guide can help in assessing your situation.

    Homeowners can protect desirable ash trees with diameters of 20 inches or less at 4.5 feet above ground level (DBH) using a soil drench containing the active ingredient imidacloprid. Tree care professionals have products and techniques that can protect larger trees or that provide a longer period of protection. This thorough publication covers the insecticide options that are available.

    There is no advantage to begin preventive treatments for those living in counties shown in white until an active EAB infestation is found nearby. Unnecessary treatments are not wise expenditures, either on a monetary or ecological basis.

  2. Buy firewood where you burn it. Moving infested ash, especially as firewood, can lead to more rapid spread of this insect. We donít want to be our own worst enemy.
  3. The purple traps once used extensively across the state to survey for EAB will either be out in very limited numbers, or not at all. While the traps had limited effectiveness, they were at least a means of trying to identify new infestations. This leaves detection to extension agents, certified arborists and turf and landscape manager. Report suspected infestations to the Office of the State Entomologist or your local Cooperative Extension Office (859) 257-5838 for confirmation. New findings will be posted on this web page. Continued watchfulness by all will be necessary to limit the spread of this important invasive insect.

Sampling of infestedf ash trees in selected areas of Kentucky indicates no significant larval mortalitly above what would be expected.

Emerald ash borer emergence begins when 450 to 500 degree days (base 50 F) have accumulated starting on January 1; peak adult activity occurs at about 765 dd. You can use this UK AG Weather corn growing degree calculator / forecaster to get current information for your area. Select the station nearest you from the drop down menu, leave the biofix date at Jan 01 2014, and have the information returned to the screen. Accumulated degree days will appear in a table using temperature data up to the current date. Degree day totals beyond the current day will be calculated using historical daily high and low temperatures. Use the back arrow to return to this page.

Emerald Ash Borer Management Statement- 2012

Conservation of ash trees has been endorsed by the Coalition for Urban Ash Tree Conservation as a fundamental component of integrated pest management programs to manage the EAB in residential and municipal landscapes. Research on EAB management has identified cost-effective, environmentally-sound treatment options that can preserve ash trees though peak EAB outbreaks used in association with tree inventories and strategic removal / replacement of unhealthy ash. Follow this link to the complete Emerald Ash Borer Management Statement .


Up-to-date information on EAB insecticides, application protocols, and effectiveness can be found in Insecticide Options for Protecting Ash Trees from Emerald Ash Borer.

Identifying the EAB

EAB adults are 3/8 to 1/2-inch long and very narrow (about 1/5-inch wide). The head is blunt, the body tapers noticeably at the end of the abdomen. The wing covers are emerald green; the top of the abdomen, visible when the wings are spread, is metallic purple-red.

Newly emerged adults are most active when it is warm and sunny. They feed for several days before mating, chewing irregular notches along leaf margins. Mated females will feed for another week or two before laying eggs in bark crevices or under bark flaps on the trunk. One female will lay between 60 and 90 eggs.

Emerald ash borer EAB feeding notches on ash leaf

Many green insects can be confused with the emerald ash borer. The picture below (courtesy of the Missouri Dept Agriculture) shows an EAB along with several look-alikes. The line-up includes (top row L-R): EAB, a bark gnawing beetle (family Trogossitidae), Buprestis rufipes, green June beetle, and the caterpillar hunter. (bottom row L-R) Japanese beetle, a green tiger beetle, green stinkbug, dogbane beetle, and a metallic bee. The picture shows relative sizes and shapes of these insects.

EAB adults are capable of flying 1/2 mile or more per day but most spread from newly established sites seems to cover distances in the range of 100 yards. Long distance spread is the result of inadvertent spread by humans in infested firewood and unprocessed ash logs."

Resources and Quick Facts

This CSI: Your ash trees brochure provides an easy-to-follow checklist to help recognize ash trees, EAB infestation symptoms, and emergence holes.

Emerald Ash Borer Frequently Asked Questions for Kentuckians provides information on the EAB in Kentucky.

This emerald ash borer field guide provides pictures of various life stages of the emerald ash borer, its damage, and identification of common ash species.

Ash distribution

According to the Ky Division of Forestry, there are 130.9 million stems of white ash and 92.5 million stems of green ash in the Commonwealth. This USDA Forest Service Forest Inventory and Analysis map (above) shows the distribution of ash stems by county (darkest color = highest to lightest = lowest) based on a 2006 Forest Inventory and Analysis. Elliot county is not listed.

This USDA Forest Service list shows the numbers of ash stems by county with ranking.

Forest Inventory and Analysis Factsheet for Kentucky 2004 states that the elm-ash-cottonwood component is 6% of the Commonwealth's 11.7 million forested acres. This type has been defined as the lowland forests where American elm ( Ulmus americana ), green ash ( "Fraxinus pennsylvanica"), eastern cottonwood (Populus deltoides ") or silver maple (Acer saccharinum) comprise singly, or in any combination, the largest component of stocking. It occupies a large but irregular area on the floodplains and bottomlands of the north central United States. (Shifley and Brown 1978).

Based on a 2005 Lexington street tree survey, ash species comprised almost 11% of about 51,000 street trees. It is estimated that there are more than 10,000 ash trees in the Urban Service Area (LFUCG 2007).

The ash component of Louisville's tree population is 17%. About 5% of the trees in the Waterfront Development are ash. (Louisville City Arborist and Management of Waterfront Development).

Lexington, KY 40546-0091Phone: (859) 257-5955
UK Entomology Program Participants
John Obrycki, Department Chair and State Entomologist
Lynne Rieske-Kinney, Research, Forest Entomologist
Lee Townsend, Extension Entomologist
Joe Collins, Senior Nursery Inspector
Carl Harper, Senior Nursery Inspector, CAPS
Janet Lensing, CAPS Survey Coordinator
Janet Lensing, CAPS Survey Coordinator
S-225 Ag Science North

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This page is maintained by Lee Townsend, Department of Entomology, University of Kentucky. Please send questions or suggestions to: