Skip to main content
ARS Home » Northeast Area » Newark, Delaware » Beneficial Insects Introduction Research Unit » Research » Publications at this Location » Publication #361425

Research Project: Biological Control of Invasive Wood-Boring Insect Pests such as Emerald Ash Borer and Asian Longhorned Beetle

Location: Beneficial Insects Introduction Research Unit

Title: Establishment and early impact of Spathius galinae (Hymenoptera: Braconidae) on Emerald Ash Borer (Coleoptera: Buprestidae) in the Northeastern U.S.

item Duan, Jian
item VAN DRIESCHE, ROY - University Of Massachusetts
item CRANDALL, RYAN - University Of Massachusetts
item Schmude, Jonathan
item RUTLEDGE, CLAIRE - Connecticut Agricultural Experiment Station
item SLAGER, BENJAMIN - Animal And Plant Health Inspection Service (APHIS)
item GOULD, JULI - Animal And Plant Health Inspection Service (APHIS)
item ELKINTON, JOSEPH - University Of Massachusetts

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/4/2019
Publication Date: 6/17/2019
Citation: Duan, J.J., Van Driesche, R.G., Crandall, R.S., Schmude, J.M., Rutledge, C.E., Slager, B.H., Gould, J.R., Elkinton, J.S. 2019. Establishment and early impact of Spathius galinae (Hymenoptera: Braconidae) on Emerald Ash Borer (Coleoptera: Buprestidae) in the Northeastern U.S. Journal of Economic Entomology. 112: 2121-2130.

Interpretive Summary: The emerald ash borer (EAB) is a serious invasive forest pest that has killed tens of millions of ash trees in the United States and Canada. A classical biological control program to introduce and establish co-evolved natural enemies from the native range of EAB in northeast Asia can be an extremely cost-effective, sustainable, and environmentally benign tool for management of this pest. A parasitic wasp which is a natural enemy of EAB larvae in the Russian Far East was introduced in 2015 to the U.S. for biological control of EAB. We documented the successful establishment of this introduced wasp in 2018 at hardwood forest sites in Connecticut, Massachusetts and New York, where we observed substantial EAB larval mortality caused by the wasp. Our results suggest that this natural enemy is likely to play a critical role in protecting our ash resources against EAB.

Technical Abstract: The emerald ash borer (EAB), Agrilus planipennis, a buprestid beetle native to Asia, has become a serious invasive pest of ash trees (Fraxinus spp.) in North America since the early 2000s. Due to the impracticality of applying insecticides in natural forests, biocontrol is the most viable method to manage EAB in natural ecosystems. We report the first evidence for the establishment and impact of Spathius galinae (Braconidae), a larval parasitoid released (2015-2018) at six forested sites in Connecticut, New York, and Massachusetts. We also report current levels of parasitism in these same plots of another introduced larval EAB parasitoid, Tetrastichus planipennisi (Eulophidae). During the four years of the study, S. galinae density in sampled trees increased 1.5 to 20-fold, to a final density of 2.3 - 14.3 broods/m2 of phloem area at four of the six sites, where parasitism by S. galinae reached 13.1 - 49.2%. In contrast, both T. planipennisi density (0.1 - 2.3 broods/m2 of phloem area) and parasitism (0.1 – 5.6%) were low throughout the study at the same sites, where recoveries were made. Our data fill a critical gap in the development of a biocontrol-based emerald ash borer management plan to protect the growth and recovery of surviving ash trees capable of reaching maturity and producing replacement trees.