Tetrastichus planipennisi are small parasitoids (1.6 to 4.1 mm long). Adult females locate EAB larvae under ash bark and insert eggs into EAB larva. Parasitized EAB larva remain active for approximately one week although the parasitoids develop within and eventually consume the EAB larvae. Tetrastichus planipennisi larvae pupate inside the EAB gallery and emerge approximately 15 days after pupation by chewing an exit hole through the bark. They overwinter as larvae within the host or host gallery. Approximately 4-172 progeny are produced per EAB larva. In China, T. planipennisi completes four or more generations per year and parasitism levels range from 0-65%.
Jonathan Osthus, EAB Biological Control Coordinator
Monika Chandler, Biological Control Coordinator
Plant Protection Division