Emerald Ash Borer has been identified in four New Jersey towns.

NJ Forestry Services Report

Emerald ash borer (EAB) is a non-native insect pest that infests and kills all species of ash trees. With 24.7 million ash trees, approximately 9 percent of New Jersey forests are susceptible to emerald ash borer attacks. Although rarely the most abundant tree in a forest stand, ash is still found in 24 percent of all forest land. The greatest numbers of ash trees can be found in the northern part of the state. Ash is also commonly planted along streets, as landscape trees in yards, and in parks throughout the state. 

EAB in New Jersey
EAB was found in four New Jersey townships in 2014 in Somerset, Mercer, and Burlington Counties. EAB has also been identified in Bucks County, PA and Orange County, NY.  While all ash trees in NJ should be monitored for EAB, ash within 15 miles of known sightings should be most carefully and frequently monitored.

http://www.nj.gov/dep/parksandforests/forest/community/Emerald_Ash_Borer.htm