Spathius agrili is a parasitic non-stinging wasp of family Braconidae which is native to North Asia. It is a parasitoid of the emerald ash borer (Agrilus planipennis Fairmaire, family Buprestidae), an invasive species which has destroyed tens of millions of ash trees in its introduced range in North America. As part of the campaign against the emerald ash borer (EAB), American scientists in conjunction with the Chinese Academy of Forestry searched since 2003 for its natural enemies in the wild leading to the discovery of several parasitoid wasps, including Spathius agrili which was discovered in Tianjin, China where it is a prevalent gregarious ectoparasitoid of EAB larvae in stands of Fraxinus velutina, an ash species native to Mexico and southwestern U.S.A., and one ash tree endemic to t