Emerald Ash Borer was first confirmed in Sudbury, MA in 2020. It looks like blonding from woodpeckers going after emerald ash borer larvae.
Treatment, if caught early, can be treated by giving the affected tree extra water and fertilizer to help it recover from the damage, and with insecticides. Insecticide treatment should only be done by professional arborists. Badly infected trees must be removed and the wood either chipped or burned.
Next steps are dependent on each individual landowner, there is no state or federal treatment or removal plan for EAB. If there is less than 50% branch dieback on these ash trees, you can use a pesticide inoculation to kill the EAB larvae. If there is greater than 50% branch dieback, removal is recommended. You can read more about that process here:
A certified arborist can help you with the removal or treatment. You can find one here: https://massarbor.org/directory.php
Read More: https://ag.umass.edu/landscape/fact-sheets/emerald-ash-borer