|Emerald ash borer - Leah Bauer USDA Bugwood|
|Larval Tunnels - USDA|
Prevention is the best answer by not transporting infected ash wood, usually as firewood carried by unsuspecting campers. There are treatments for individual urban trees but none for our forests in general. MDC has published a new four-page guide called the Emerald Ash Borer Management Guide for Missouri Homeowners. The guide can be found at this link.
Comprehensive current information is on this Wikipedia site.