Living with emerald ash borer: Larger, older trees attacked first
Tara L. Eberhart, firstname.lastname@example.org and Andrew J. Storer, email@example.com. Michigan Technological University, School of Forest Resources and Environmental Science, 1400 Townsend Dr, Houghton, MI
The exotic emerald ash borer, Agrilus planipennis (Coleoptera: Buprestidae) is currently established in Michigan and some surrounding states. At high population densities, all green, black, and white ash trees are apparently susceptible to attack and can be expected to die. The first record of this insect in Upper Michigan was from Brimley State Park in the fall of 2005 as part of an ongoing detection survey. Eradication efforts involving removal of ash trees provided the opportunity to remove discs from trees for dendrochronology analyses. We determined if tree age, tree size, or tree growth affected the likelihood of the occurrence of emerald ash borer larvae in an ash tree in the early stages of infestation, when the population density is still relatively low. Both non-linear regression and ranked tree data showed that tree age and tree size were significantly related to the presence of EAB larvae, with the larger, older trees more likely to be infested. Tree growth (mean basal area increment) was also lower on attacked trees. Since 1995, trees attacked by EAB had consistently lower growth rates, suggesting there are other factors that reduced growth and may have predisposed them to EAB attack.
Species 1: Coleoptera Buprestidae Agrilusplanipennis (emerald ash borer)