University program helps battle emerald ash borer

A University Extension program trains people to detect the insect in trees.

Adam Daniels

The emerald ash borer is a menace that is encroaching on the University of Minnesota campus, and a University Extension program is looking to help fix the problem. The program helps the Minnesota Department of Agriculture and the Department of Natural Resources train forestry workers to examine ash trees to detect the presence of emerald ash borer. The half-inch beetle carves its way under the treeâÄôs bark and lays its eggs. The larvae feed on the treeâÄôs inner bark and kill it by hindering the treeâÄôs ability to transport water and nutrients. Previous reports have estimated that 1,300 trees on the University campus could be infested. A seven- to 10-year plan to remove suspected EAB-infested trees began in late 2009, and University Facilities Management was awarded a $200,000 Forest Protection Reserve Grant from the MDA in January to help in this effort. Every tree suspected of being infested is removed, and University Extension professor Jeff Hahn said the key to detecting and understanding EAB is education. University Extension has trained close to 200 volunteers as first detectors. These first detectors help homeowners determine if their ash trees have been infested. Using drawknives to peel away bark, participants look closely for recognizable indicators. D-shaped exit holes are indicators, but they are very small and hard to see. Larvae carve out paths known as galleries and can only be under the bark. Holes created by woodpeckers could be a sign as well, as woodpeckers feed on EAB. Currently, first detectors can gain hands-on experience though Emerald Ash Borer Field Days, which began in March. The last of six sessions is scheduled for April 15. Sponsored by the city of St. Paul and the MDA, participants have the opportunity to look at EAB-infested trees. âÄúOur primary responsibility is outreach,âÄù Hahn said. âÄúWe help the [MDA] and the [DNR] communicate with the public.âÄù The first North American case of EAB was discovered in 2002. Since then, it has killed tens of millions of ash trees in more than a dozen states. In May 2009, EAB was discovered in Minnesota, which has 900 million ash trees, the nationâÄôs second-largest concentration. âÄúItâÄôs hard to know if thereâÄôs EAB in a tree,âÄù said Rachel Coyle from the St. Paul Forestry Department. âÄúHaving to do some kind of damage to the tree is how youâÄôre actually going to see it. ItâÄôs a needle in a haystack.âÄù Simply checking for âÄúdieback,âÄù or if a tree looks to be dead, is not a good method of detection, Hahn said. As an example, Hahn said that when the University was removing two trees for aesthetic reasons in August, EAB were detected in the one Hahn described as âÄúfull, with healthy canopy.âÄù The other was âÄúreally scraggily, severely decliningâÄù and did not have EAB. âÄúWhen this training was offered, I wanted to take advantage of it,âÄù first detector and Anoka County master gardener Pam Hartley said. âÄúBecause the more I know, the better IâÄôm able to help the residents of Minnesota.âÄù The samples used at the Field Days are all infected by EAB and were removed by the city of St. Paul. The current policy is to remove trees suspected to have EAB and replace them. The city does not treat trees with insecticides. âÄúFrom a city standpoint, we donâÄôt want to start treating thousands of trees with insecticides when we arenâÄôt sure what the long-term effects could be,âÄù Coyle said. Homeowners, however, can opt to treat the ash trees on their property with insecticides instead of removing them. âÄúOne woman said it blocks a lot of noise, so she doesnâÄôt want to get rid of the tree, even though she knows itâÄôs not at its most beautiful,âÄù Coyle said. âÄúThe research theyâÄôve done shows a lot of the insecticides are working.âÄù As more information is being found, more plans are in the works to help further awareness. Hahn said a forest entomologist will start later this year at the University and will be conducting further research on EAB. University Extension will team up with the MDA and DNR this summer for the Train the Trainer program, which will focus on directly educating the public. âÄúWeâÄôll give people the tools to deliver information to others in their community,âÄù said Hahn. âÄúThe more people know, the more can be accomplished.âÄù