Probable Emerald Ash Borer infestations in Arnold
There are 12 ash trees on Clausen Lane in Arnold that are very likely infested. All have varying amounts of die-off- probably from 10 to 50%, and characteristic 'D' exit holes. At least one tree has split bark with the squiggly bore patterns inside. These trees were planted as saplings in 1999 and are now 40-60 inches circumference (breast height). We have just treated the trees with imidacloprid soil drench this past week.
Emerald ash borer is now established all over the state of Maryland. All ash in Maryland will be killed by EAB unless it is treated (into the indefinite future). Usually only valuable specimen trees are treated. No ash tree species have been found to be resistant to this invasive insect pest.
Please read through the EAB material on our website, including the "decision tree" to help decide when to treat and when to remove a tree: http://extension.umd.edu/hgic/invasives/emerald-ash-borer
Keep in mind that ash quickly becomes very brittle when it dies and hazardous and difficult to remove. For this reason, removing the tree before it is entirely dead can reduce the cost.