From Kentucky Transportation Cabinet Department of Highways District 2 on July 16, 2009:

Purple prisms along Kentucky highways generate speculation
Insect traps aimed at monitoring spread of emerald ash borer

MADISONVILLE, Ky. — If you’ve driven along the Wendell Ford-Western Kentucky Parkway or any number of other highways in Western Kentucky you may have noticed some odd looking purple prisms hanging in trees along the roadside. The strange looking structures have generated several dozen calls to the Kentucky Transportation Cabinet and area police agencies.

According to Kentucky State Entomologist Dr. John J. Obrycki, the oddly shaped bright purple structures are taps put out to monitor the spread of the emerald ash borer.

“The emerald ash borer is a small, dark green metallic beetle that attacks all species of ash trees. Adult borers feed on tree leaves. The larvae can burrow into the tree to feed on the bark, destroying the tree's ability to transport water and nutrients to leaves and limbs,” Obrycki said.

An infestation by the emerald ash borer can cause loss of the entire canopy within a year or two.

Kentucky Transportation Cabinet spokesman Keith Todd says his agency has received several dozen calls with inquiries about the purple structures hanging in trees.

“Dr. Obrycki and his UK researchers have placed a number of the insect traps along the Western Kentucky Parkway and other highways across the region,” Todd said. “Our switchboard people received several calls from the public and several people called me personally to ask about them. I eventually encountered one of the purple prisms in rural Crittenden County. I called the Kentucky Fish and Wildlife people. They directed me to the Kentucky Department of Agriculture where they led me to Dr. Obrycki who explained their purpose.”

About 6,000 of the purple prism traps have been hung in ash trees primarily along the northern border of Kentucky from Ballard County to Boyd County. The trapping area is 2- to 3-counties wide along that band. In addition, traps are being placed in campgrounds, state and national parks, other tourist attractions, and interstate rest areas. No emerald ash borers (EAB) were found in any of the approximately 3,000 traps placed in Kentucky during the summer of 2008. The most current information on EAB in Kentucky is available at http://pest.ca.uky.edu/EXT/EAB/welcome.html .

The 24-inch long traps, baited with a combination of oils, will remain in place until August, the end of the EAB flight period. Adults of the metallic woodborers (family containing the EAB) are attracted to red and purple hues. The oils contain four compounds that are released by stressed ash trees and are among the cues used by borers to find host trees. Sticky surfaces of the trap will collect the beetles; there are no toxins or insecticides in the traps.

The borer was discovered in Michigan in 2002 and since then has destroyed more than 40 million trees in 10 states and cost countless numbers of homeowners millions of dollars in tree removal and replacement.

About 3,000 traps were put up across the Kentucky in 2008. While no infestations were found, it's likely to happen in the future because the borer has been found as close as Cincinnati, said Lee Townsend, extension entomologist in the University of Kentucky College of Agriculture.

The traps are part of an emerald ash borer survey, funded by the U.S. Department of Agriculture Animal Plant Health Inspection Service and U.S. Forest Service. The Kentucky Office of the State Entomologist began overseeing the installation of traps during the third weekend in May. Traps are placed along the Ohio River from Ballard County to Boyd County and about two counties deep. In addition, traps will be at rest areas, campgrounds, state parks and other tourist attractions across the state. In total, they will install about 6,000 traps that will remain in place through the borer's flight, which ends in August.

The traps are about 2-feet-long and baited with a combination of oils to attract the borers if they are present in the state. Traps will not cause any harm to humans, animals or trees.

"These traps do not contain anything toxic and are not going to cause infestations to develop," Townsend said. "They are designed to find insects that are already there."

If emerald ash borer infestation is suspected, contact the USDA-APHIS Emerald Ash Borer hotline at 866-322-4512 or the Kentucky Office of the State Entomologist at 859-257-5838.

For more info go to http://www.uky.edu/Ag/kpn/kpn_09/pn_090519.html#WatchFor .

Contact: Lee Townsend, 859-257-7455
John J. Obrycki
Professor and Chair
Department of Entomology
University of Kentucky
Lexington, KY 40546-0091
PH: 859-257-7450
FAX: 859-323-1120