As part of the campaign against the emerald ash borer Elliot Elsley (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 Oobius agrili which is a solitary egg parasitoid of EAB on ash trees in Jilin province in 2004 and has been recorded to kill up to 60 percent of EAB eggs.