Emerald Ash Borer Problem?
Ash trees that should be treated with a protective insecticide are ones that have minimal or no outward damage from emerald ash borer and are otherwise healthy. From the photos, it looks like there is bark cracking/peeling on the trunk about 1.5 feet below the crotch. Also, from the photos it looks like there is a large branch to the right has dying leaves. If that is the case, then it is likely too late to save the
If you have other ash trees on your property with less damage, you may consider contacting an arborist to treat those. In Maryland, there are no longer any products that homeowners can apply for protection against emerald ash borer, but an arborist can inject an insecticide into the trunk that will last for several years. See the last link to find an ISA certified arborist in the area.
If you have further questions, feel free to email (firstname.lastname@example.org), call (301-934-5404) or stop by the office (9501 Crain Highway, Bel Alton).