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Leah Bauer

Leah Bauer
Research Entomologist, Emerit
Ecology and Management of Invasive Species and Forest Ecosystems
3101 Discovery Dr., Ste. F
Lansing, MI 48910
United States
Current Research

My research has focused on key mortality factors that regulate populations of the emerald ash borer (EAB) [Agrilus planipennis (Coleoptera: Buprestidae)] in North America, where this invasive beetle is killing native ash (Fraxinus) trees, and in its native range in Asia where it is considered only a minor ash pest. A better understanding of EAB population dynamics may facilitate the development of safe, long-term, and sustainable management strategies to better protect ash from EAB in North America. Biological control is the generally accepted method for managing invasive pests, mainly insects and weeds, in environmentally sensitive ecosystems such as forests. USDA began an EAB biocontrol program in 2007, with the approval for release of three parasitoid species from China [Tetrastichus planipennisi (Eulophidae), Oobius agrili (Encyrtidae), Spathius agrili (Braconidae)] in the U.S.  A fourth species from Russian Far East [Spathius galinae (Braconidae)], was approved for release in 2015. These four parasitoid species are currently being reared and shipped by USDA APHIS for release in the U.S. by researchers, forest managers, and landowners. Research continues on the establishment and prevalence of native and introduced EAB parasitoids, as well as the impacts of biocontrol on EAB population densities, ash health, and forest recovery in the aftermath of EAB. 

Research Interest

My collaborative research continues at long-term study sites in Michigan where we are evaluating parasitoid establishment, spread, impacts on EAB population dynamics, and impacts on ash regeneration and survival.

Why This Research Is Important

Emerald ash borer (EAB), an invasive beetle from Asia is spreading in North America, causing widespread mortality of native ash (Fraxinus) trees. EAB was first discovered in southeast Michigan in 2002 and likely arrived during the 1990s in EAB-infested solid-wood packaging materials used for international trade with Asia. Despite early efforts by regulatory agencies to eradicate EAB, infestations are known in 35 states, the District of Columbia, and four Canadian provinces as of August 2018. The ecological impacts of the EAB invasion are rapidly changing the biodiversity, species composition, hydrologic processes, and nutrient and carbon cycles in our forests. The survival of ash species native to North America may require a combination of both biocontrol and the discovery or development or EAB-resistant ash genotypes.

  • University of Kentucky, Ph.D., Entomology, 1987
  • University of Maine, M.S., Entomology, 1977
  • University of Michigan, B.S., Natural Resources, 1974
Professional Organizations
  • Entomological Society of America,  Current
  • Society for Invertebrate Pathology (SIP),  Current
  • International Organization for Biological Control,  Current
  • Michigan Entomological Society,  Current
Featured Publications
Other Publications
Citations of Non-Forest Service Publications