Tetrastichus planipennisi is a parasitic non stinging wasp of family Eulophidae 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 Tetrastichus planipennisi which is a gregarious endoparasitoid of EAB larvae on Manchurian Ash (Fraxinus mandschurica) and has been recorded to attack and kill up to 50 percent of EAB larvae.
Tetrastichus planipennisi parasitize EAB larvae by drilling through the bark and laying eggs on its host. The hatching parasitoid larvae feed and develop on the EAB larva, resulting in its death. Tetrastichus completes at least four generations each year and one EAB larva can produce up to 127 Tetrastichus adults. Tetrastichus planipennisi survive the winter as larvae inside their host or host gallery under the bark of ash trees.
Tetrastichus planipennisi, a gregarious larval endoparasitoid, has been introduced and released into the United States of America as a possible biological control of the EAB along with two other wasps, Oobius agrili, a solitary, parthenogenic egg parasitoid, and Spathius agrili, a gregarious larval ectoparasitoid. However of the three, Tetrastichus planipennisi has showed best results in affecting EAB and establishing surviving populations.
Research on the viability of as an effective biocontrol agent is ongoing in the US. Laboratory methods have been developed for continuous rearing of this and other species of EAB parasitoid wasps. Extensive studies on the specificity of these parasitoids on native beetles and other insects has revealed that in laboratory no-choice assays, Tetrastichus attacked only actively feeding EAB larvae in ash branches and rejected all non-EAB species as hosts.
- Yang, Z.-qi; J. S. Strazanac; Y.-X. Yao; X.-Y. Wang (2006). "A new species of emerald ash borer parasitoid from China belonging to the genus Tetrastichus Haliday (Hymneoptera: Eulophidae)". Proceedings of the Entomological Society of Washington. 108 (3): 550–558.
- Gould, Juli; Bauer, Leah, "Biological Control of Emerald Ash Borer (Agrilus planipennis)" (PDF), Animal and Plant Health Inspection Service (APHIS), United States Department of Agriculture, retrieved 28 April 2011
- "Biocontrol: Fungus and Wasps Released to Control Emerald Ash Borer". Science News. ScienceDaily. 26 April 2011. Retrieved 27 April 2011.
- Bauer, L.S.; Liu, H-P; Miller, D.; Gould, J. (2008). "Developing a classical biological control program for Agrilus planipennis (Coleoptera: Buprestidae), an invasive ash pest in North America" (PDF). Newsletter of the Michigan Entomological Society. 53 (3&4): 38–39. Retrieved 29 April 2011.