Spathius galinae are small parasitoids. Adult females locate EAB larvae under ash bark, paralyze and lay eggs on the outside of the EAB larva. Parasitoid larvae develop and consume the EAB larva. S. galinae larvae pupate inside the EAB gallery and emerge approximately 1 month later by chewing an exit hole through the bark. They overwinter as larvae within the host gallery. Approximately 5-12 individuals are produced per EAB larva. In the Russian Far East, S. galinae completes two generations per year with parasitism rates averaging 63%.