''Tetrastichus planipennisi'' is a parasitic non-stinging wasp of the family

Eulophidae The Eulophidae are a large family of hymenopteran insects, with over 4,300 described species in some 300 genera. The family includes the genus ''Elasmus'', which used to be treated as a separate family, "Elasmidae", and is now treated as a subf ...

which is native to

North Asia North Asia or Northern Asia, also referred to as Siberia, is the northern region of Asia, which is defined in geographical terms and is coextensive with the Asian part of Russia, and consists of three Russian regions east of the Ural Mountains: ...

. It is a parasitoid of the

emerald ash borer The emerald ash borer (''Agrilus planipennis''), also known by the acronym EAB, is a green buprestid or jewel beetle native to north-eastern Asia that feeds on ash species. Females lay eggs in bark crevices on ash trees, and larvae feed undern ...

(''

Agrilus planipennis The emerald ash borer (''Agrilus planipennis''), also known by the acronym EAB, is a green buprestid or jewel beetle native to north-eastern Asia that feeds on ash species. Females lay eggs in bark crevices on ash trees, and larvae feed undern ...

'' Fairmaire, family

Buprestidae Buprestidae is a family of beetles known as jewel beetles or metallic wood-boring beetles because of their glossy iridescent colors. Larvae of this family are known as flatheaded borers. The family is among the largest of the beetles, with some ...

), an

invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...

which has destroyed tens of millions of

ash trees ''Fraxinus'' (), commonly called ash, is a genus of flowering plants in the olive and lilac family, Oleaceae. It contains 45–65 species of usually medium to large trees, mostly deciduous, though a number of subtropical species are evergr ...

in its introduced range in

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

. As part of the campaign against the emerald ash borer (EAB), American scientists in conjunction with the

Chinese Academy of Forestry Chinese can refer to: * Something related to China * Chinese people, people of Chinese nationality, citizenship, and/or ethnicity **''Zhonghua minzu'', the supra-ethnic concept of the Chinese nation ** List of ethnic groups in China, people of va ...

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 In evolutionary ecology, a parasitoid is an organism that lives in close association with its host at the host's expense, eventually resulting in the death of the host. Parasitoidism is one of six major evolutionary strategies within parasitis ...

of EAB larvae on Manchurian Ash (''

Fraxinus mandschurica ''Fraxinus mandshurica'', the Manchurian ash, is a species of ''Fraxinus'' native to northeastern Asia in northern China (Gansu, Hebei, Heilongjiang, Henan, Hubei, Jilin, Liaoning, Shaanxi, Shanxi), Korea, Japan and southeastern Russia ( Sakhali ...

'') and has been recorded to attack and kill up to 50 percent of EAB larvae.

Life cycle

''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.

Biological control

''Tetrastichus planipennisi'', a gregarious larval endoparasitoid, has been introduced and released into the

United States of America The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territo ...

as a possible

biological control Biological control or biocontrol is a method of controlling pests, such as insects, mites, weeds, and plant diseases, using other organisms. It relies on predation, parasitism, herbivory, or other natural mechanisms, but typically also invo ...

of the EAB along with two other wasps, ''

Oobius agrili ''Oobius agrili'' is a parasitic non-stinging wasp of family Encyrtidae 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 destroye ...

'', a solitary, parthenogenic egg parasitoid, and ''

Spathius agrili ''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), an invasive species which has destroyed tens of millions of ...

'', 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 and Canada. 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.

References

{{Taxonbar, from=Q7706750 Eulophidae Insects used as insect pest control agents Insects described in 2006