Leah Bauer
Title: Research Entomologist
Unit: Ecology and Management of Invasive Species and Forest Ecosystems
Previous Unit: Providing New Information on the Biology, Ecology, and Management of Exotic Invasive Forest Insects
Address: Northern Research Station
Stephen S. Nisbet Bldg., 1407 S. Harrison Road, Room 220
East Lansing, MI 48823
Phone: 517-355-7740; ext. 103
E-mail: Contact Leah Bauer
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Education
- University of Kentucky, Ph.D. Entomology, 1987
- University of Maine, M.S. Entomology, 1977
- University of Michigan, B.S. Natural Resources, 1974
Civic & Professional Affiliations
- Entomological Society of America
- Society for Invertebrate Pathology
- International Organization for Biological Control
- Michigan Entomological Society
Current Research
My current research is focused on key mortality factors regulating populations of the emerald ash borer (EAB) in North America, where this invasive beetle has killed millions of ash trees, and in its native range in northeastern Asia, where it is considered only a minor ash pest. A better understanding of the biology and population dynamics of EAB will facilitate the development of safe, long-term, and sustainable management strategies for this destructive, non-native pest in North America. These strategies include biological and microbial controls, which are management tools generally considered acceptable for management of insects in environmentally sensitive areas such as forests and riparian areas. Biological control of EAB will likely involve introducing EAB-specific natural enemies from Asia to EAB populations in North America. Microbial control of EAB will involve the development and use of microbial insecticides registered by the U.S. Environmental Protection Agency (EPA). Microbial insecticides formulated with the insect pathogen Bacillus thuringiensis (Bt) are applied aerially in North America to manage insect pests in forested and riparian areas such as gypsy moth.
In collaborative studies with scientists at Michigan State University (MSU), we determined that few natural enemies attack EAB in Michigan. Expanded research in China , with scientists at the Chinese Academy of Forestry in Beijing, led to the discovery of several EAB populations where we are studying its natural enemy complex. During the course of this research in China, we discovered two new species of wasps that parasitize and kill EAB: Tetrastichus planipennisi (Eulophidae), a gregarious larval endoparasitoid, and Oobius agrili (Encyrtidae),a solitary parthenogenic egg parasitoid. In 2005, we completed a study on the population biology of these two parasitic wasps, which overlap in an ash forest in Jilin Province China and reduced EAB populations by 74%. We have also completed research on parasitoid biology, developed laboratory rearing and storage methods, and evaluated host specificity for both species in our quarantine laboratory. In 2007, we requested approval to release these parasitoids in selected Michigan field sites to evaluate establishment, monitor spread rates, and determine effects on EAB population dynamics and ash survival.
We are also studying the potential use of insect pathogenic microorganisms for management of EAB. If host-specific entomopathogens are found infecting EAB from China, these may prove useful as biocontrol agents through inoculative release into EAB populations, resulting in population crash (epizootic) or decline (enzootic). We are also studying the potential use of BotaniGard?, a microbial insecticide formulated with the insect pathogenic fungus Beauveria bassiana GHA, for suppression of EAB populations. This research began in 2002 after discovering the importance of fungal entompathogens as natural enemies of EAB in Michigan. In 2006, expanded field trials were initiated in collaboration with scientists from USDA ARS and Cornell University from Ithaca, NY. Research on a Bacillus thuringiensis- based microbial insecticide (Bt), which will target adult EAB via aerial application, is currently in the developmental phase.
Why is This Important
EAB was first discovered in southeastern Michigan in 2002 and likely arrived in infested wooden packing materials used for international trade with Asia. EAB may have gone undetected for at least a decade due to widespread ash decline throughout the eastern U.S. EAB has since been found killing ash trees in Ontario, Ohio, Indiana, Maryland, Virginia, and Illinois, and efforts to slow its spread are underway in some isolated infestations. Once established, however, managers have found that eradication is not possible due to rapid dispersal of adult beetles throughout forested areas with abundant ash; lack of detection and control methods; and lack of compliance with quarantine regulations designed to prevent human transport of EAB-infested firewood, logs, and nursery stock. USDA APHIS predicted the establishment of EAB nationally within urban landscapes will result in the loss of up to 30-90 million trees, equivalent to 2% total leaf area and valued at $20-60 billion. USDA FS estimated the costs of tree removal and replacement by local governments and homeowners over the next 25 years at $7 billion (present dollars). EAB is now well established in natural ecosystems in Lower Michigan and parts of Ohio and Indiana. At present, managers estimate EAB has killed ca. 20 million trees in Michigan, a fraction of the >800 million ash trees in Michigan timberlands. The impact of EAB on urban areas, ash resources, forest biodiversity, and climate in North America will be profound. Clearly, sustainable and environmentally acceptable methods to manage the EAB invasion are justified and needed.
Future Research
If biological control is approved in North America, I will continue studying parasitoid establishment, spread, and impact on EAB and ash. Foreign exploration in China continues as we search for entomopathogens and more parasitoids. Once a Bt-based insecticide is developed and registered against EAB adults, aerial field trials will be needed to evaluate its efficacy for EAB eradication, suppression, and slow the spread programs in North America.
Featured Publications
- Liu, Houping; Bauer, Leah S.; Miller, Deborah L.; Zhao, Tonghai; Gao, Ruitong; Song, Liwen; Luan, Qingshu; Jin, Ruozhong; Gao, Changqi. 2007. Seasonal abundance of Agrilus planipennis (Coleoptera: Buprestidae) and its natural enemies Oobius agrili (Hymenoptera: Encyrtidae) and Tetrastichus planipennisi (Hymenoptera: Eulophidae) in China. Biological Control. 42: 61-71.
- Zhang, Yanzhou; Huang, Dawei; Zhao, Tonghai; Liu, Houping; Bauer, Leah S. 2005. Two New Species of Egg Parasitoids (Hymenoptera:Encyrtidae) of Wood-Boring Beetle Pests from China. Phytoparasitica 33:3, 2005
- Lui, Houping; Bauer, Leah S. 2006. Susceptibility of Agrilus planipennis (Coleoptera: Buprestidae) to Beauveria bassiana and Metarhizium anisopliae. Journal of Economic Entomology. 99(4): 1096-1103.
Additional
Online Publications
- Lui, Houping; Bauer, Leah S. 2008. Emerald Ash Borer Microbial Control with the Entomopathogen Beauveria bassiana GHA formulated as Botanigard®
- Bray, Alicia M.; Bauer, Leah S.; Haack, Robert A.; Poland, Therese; Smith, James J. 2008. Emerald ash borer genetics: an update
- Vasanthakumar, Archana; Handelsman, Jo; Schloss, Patrick D.; Bauer, Leah S.; Raffa, Kenneth F. 2008. Gut microbiota of an invasive subcortical beetle, Agrilus planipennis Fairmaire, across various life stages
- Liu, Houping; Bauer, Leah S. 2008. Microbial control of Agrilus planipennis (Coleoptera: Buprestidae) with Beauveria bassiana strain GHA: field applications
- Liu, Houping; Bauer, Leah S. 2008. Microbial control of emerald ash borer, Agrilus planipennis (Coleoptera: Buprestidae) with Beauveria bassiana strain GHA: Greenhouse and field trials
- Hajek, Ann E.; Burke, Allison E.; Nielsen, Charlotte; Hannam, Joshua J.; Bauer, Leah S. 2008. Nondormancy in Entomophaga maimaiga azygospores: effects of isolate and cold exposure
- Liu, Houping; Bauer, Leah S.; Zhao, Tonghai; Gao, Ruitong. 2008. Population biology of emerald ash borer and its natural enemies in China
- Bauer, Leah S.; Liu, Houping; Gould, Juli. 2008. Progress on biological control of emerald ash borer
- Dubois, Thomas; Lund, Jennifer; Bauer, Leah S.; Hajek, Ann E. 2008. Virulence of entomopathogenic hypocrealean fungi infecting Anoplophora glabripennis
- Bauer, Leah S.; Liu, Houping. 2007. Oobius Agrili (Hymentoptera: Encyrtidae), a solitary egg parasitoid of emerald ash borer from China
- Liu, Houping; Bauer, Leah S. 2007. Tetrastichus Planipennisis (Hymenoptera: Eulophidae), a gregarious larval endoparasitoid of emerald ash borer from China
- Taylor, Robin A.; Poland, Therese M.; Bauer, Leah S.; Windell, Keith N.; Kautz, James L. 2007. Emerald ash borer flight estimates revised
- Bray, Alicia M.; Bauer, Leah S.; Fuester, Roger W.; Choo, Ho Yul; Lee, Dong Woon; Kamata, Naoto; Smith, James J. 2007. Expanded explorations for emerald ash borer in Asia and implications for genetic analysis
- Liu, Houping; Bauer, Leah S. 2007. Is biological control a management option for emerald ash borer in North America?
- Hajek, Ann E.; Dubois, Thomas; Lund, Jennifer; Shanley, Ryan; Bauer, Leah; Smith, Michael; Fan, Peng; Bo, Huang; Jiafu, Hu; Li, Zengzhi. 2007. Microbial control of Asian longhorned beetles - what are fungal bands?
- Bauer, L.S.; Liu, H.P.; Gould, J.; Reardon, R. 2007. Progress on Biological Control of the Emerald Ash Borer in North America
- Haack, Robert A.; Bauer, Leah S.; Gao, Rui-Tong; McCarthy, Joseph J.; Miller, Deborah L.; Petrice, Toby R.; Poland, Therese M. 2006. Anoplophora glabripennis within-tree distribution, seasonal development, and host suitability in China and Chicago
- Fallon, Declan J.; Solter, Leellen F.; Bauer, Leah S.; Miller, Deborah L.; Cate, James R.; McManus, Michael L. 2006. Effect of entomopathogenic nematodes on Plectrodera scalator (Fabricius) (Coleoptera: Cerambycidae)
- Poland, Therese M.; Haack, Robert A.; Petrice, Toby R.; Miller, Deborah L.; Bauer, Leonora S.; Gao, Ruitong. 2006. Field Evaluations of Systemic Insecticides for Control of Anoplophora glabripennis (Coleoptera: Cerambycidae) in China
- Poland, Therese M.; Haack, Robert A.; Petrice, Toby R.; Miller, Deborah L.; Bauer, Leonora S. 2006. Laboratory Evaluation of the Toxicity of Systemic Insecticides for Control of Anoplophora glabripennis and Plectrodera scalator (Coleoptera: Cerambycidae)
- Gates, Michael W.; Liu, Houping; Bauer, Leah S.; Schauff, Michael E. 2005. A new species of Pediobius (hymenoptera: eulophidae) parasitizing Chyliza apicalis (Diptera: Psilidae) in ash trees attacked by Agrilus planipennis (Coleoptera: Buprestidae)
- Fleming, Mary R.; Janowiak, John J.; Kimmel, Jeffrey D.; Halbrendt, John M.; Bauer, Leah S.; Miller, Deborah L.; Hoover, Kelli. 2005. Efficacy of commercial microwave equipment for eradication of pine wood nematodes and cerambycid larvae infesting red pine
- Fleming, Mary R.; Agrawal, Dinesh K.; Bhardwaj, Mahesh C.; Bauer, Leah S.; Janowiak, John J.; Miller, Deborah L.; Shield, Jeffrey E.; Hoover, Kelli; Roy, Rustum. 2005. Noncontact ultrasound detection of exotic insects in wood packing materials
- Fleming, Mary R.; Janowiak, John J.; Kearns, Joseph; Shield, Jeffrey E.; Roy, Rustum; Agrawal, Dinesh K.; Bauer, Leah S.; Miller, Deborah L.; Hoover, Kelli. 2004. Parameters for scale-up of lethal microwave treatment to eradicate cerambycid larvae infesting solid wood packing materials
- Bauer, Leah S.; Haack, Robert A.; Miller, Deborah L.; Petrice, Toby R.; Liu, Houping. 2003. Emerald ash borer life cycle
- Liu, Houping; Petrice, Toby R.; Bauer, Leah S.; Haack, Robert A.; Gao, Ruitong; Zhao, Tonghai. 2003. Exploration for emerald ash borer in China
- Liu, Houping; Bauer, Leah S.; Gao, Ruitong; Zhao, Tonghai; Petrice, Toby R.; Haack, Robert A. 2003. Exploratory survey for the emerald ash borer, Agrilus planipennis (Coleoptera: Buprestidae), and its natural enemies in China.
- Bauer, Leah S.; Miller, Deborah L.; Taylor, Robin A.J.; Haack, Robert A. 2003. Flight potential of the emerald ash borer
- Smith, Jim; Haack, Bob; Bauer, Leah. 2003. Genetic analysis of emerald ash borer (Agrilus Planipennis Fairmaire) to determine point of origin in North American infestations
- Haack, Robert A.; Petrice, Toby R.; Miller, Deborah L.; Bauer, Leah S.; Schiff, Nathan M. 2003. Host range of emerald ash borer
- Bauer, Leah S.; Haack, Robert A.; Miller, Deborah L.; Liu, Houping; Petrice, Toby. 2003. Laboratory rearing of emerald ash borer
- Bauer, Leah S.; Liu, Houping; Miller, Deborah L. 2003. Microbial control of the emerald ash borer
- Bauer, Leah S.; Liu, Houping; Haack, Robert A.; Petrice, Toby R.; Miller, Deborah L. 2003. Natural enemies of emerald ash borer in southeastern Michigan
- Loseva, Olga; Ibrahim, Mohamed; Candas, Mehmet; Koller, C. Noah; Bauer, Leah S.; Bulla, Lee A. Jr. 2002. Changes in protease activity and Cry3Aa toxin binding in the Colorado potato beetle: implications for insect resistance to Bacillus thuringiensis toxins
- Andresen, J.A.; McCullough, D.G.; Potter, B.E.; Koller, C.N.; Bauer, L.S.; Ramm, C. W. 2001. Effects of winter temperatures on gypsy moth egg masses in the Great Lakes region of the United States.
- Hajek, Ann E.; Wheeler, Micheal M.; Eastburn, Callie C.; Bauer, Leah S. 2001. Storage of resting spores of the gypsy moth fungal pathogen, Entomophaga maimaiga
- Mccullough, Deborah C.; Bauer, Leah S. 2000. Bt: One Option for Gypsy Moth Management
- Wu, Sheng-Jiun; Koller, Noah C.; Miller, Deborah L.; Bauer, Leah S.; Dean, Donald H. 2000. Enhanced toxicity of Bacikkus thuringiensis Cry3A 8-endotoxin in coleopterans by mutagenesis in recetor binding loop
- Bauer, Leonora S. 1999. Gypsy moths get sick too!
- Federici, Brian A.; Bauer, Leah S. 1998. Cyt1Aa protein of Bacillus thuringiensis is toxic to the Cottonwood Leaf Beetle, Chrysomela scripta, and suppresses high levels of resistance to Cry3Aa
- Hajek, A. E.; Bauer, L.; McManus, M. L.; Wheeler, M. M. 1998. Distribution of resting spores of the Lymantria dispar pathogen Entomophaga maimaiga in soil and on bark
- Bauer, Leah S.; Miller, Deborah L.; Maddox, Joseph V.; McManus, Michael L. 1998. Interaction between a Nosema sp. (Microspora: Nosematidae) and Nuclear Polyhedrosis Virus Infecting the Gypsy Moth, Lymantria dispar (Lepidoptera: Lymantriidae)1
- Park, Hyun-woo; Ge, Baoxue; Bauer, Leah S.; Federici, Brian A. 1998. Optimization of Cry3A yields in Bacillus thuringiensis by use of sporulation-dependent promoters in combination with the STAB-SD mRNA sequence
- Bauer, Leah S. 1997. Fiber farming with insecticidal
- Herms, Catherine Papp; McCullough, Deborah G.; Bauer, Leah S.; Haack, Robert A.; Miller, Deborah L.; Dubois, Norman R. 1997. Susceptibility of the endangered Karner blue butterfly (Lepidoptera: Lycaenidae) to Bacillus thuringiensis var. kurstaki used for gypsy moth suppression in Michigan
- Herms, Catherine Papps; McCullough, Deborah G.; Miller, Deborah L.; Bauer, Leah S.; Haack, Robert A. 1996. Laboratory rearing of Lycaeides melissa samuelis (Lepidoptera: Lycaenidae), an endangered butterfly in Michigan
- Koller, C. Noah; Bauer, Leah S.; Hollingworth, Robert M. 1995. A method for in Vivo radiolabeling Bacillus thuringiensis native δ-endotoxin crystals
- Smitley, D. R.; Bauer, L. S.; Hajek, A. E.; Sapio, F. J.; Humber, R. A. 1995. Introduction and establishment of Entomophaga maimaiga, a fungal pathogen of gypsy moth (Lepidoptera: Lymantriidae) in Michigan
- Bauer, Leah S. 1995. Resistance: a threat to the insecticidal crystal proteins of Bacillus thuringiensis
- Bauer, Leah S.; Pankratz, Stuart H. 1993. Nosema scripta N. Sp. (Microsporida: Nosematidae), a Microsporidian Parasite of the Cottonwood Leaf Beetle, Chrysomela scripta (Coleoptera: Chrysomelidae)1
- Koller, C. N.; Bauer, L. S.; Hollingworth, R. M. 1992. Characterization of the pH-Mediated solubility of Bacillus thuringiensis var. san diego native δ-endotoxin crystals
- Bauer, Leah S. 1992. Response of the Imported Willow Leaf Beetle to Bacillus thuringiensis var. san diego on Poplar Willow1
- Bauer, Leah S.; Pankratz, Stuart H. 1992. Ultrastructural Effects of Bacillus thuringiensis var. san diego on Midgut Cells of the Cottonwood Leaf Beetle1
- Bauer, L. S.; McManus, M.; Maddox, J. 1991. Interactions between nuclear polyhedrosis virus and Nosema sp. infecting gypsy moth
- Bauer, Leah S. 1990. Response of the Cottonwood Leaf Beetle (Coleoptera: Chrysomelidae) to Bacillus thuringiensis var. san diego
- Bauer, Leah S.; Meerschaert, Joann; Forrester, Thomas O. 1989. An Artificial Diet for Cottonwood and Imported Williow leaf Beetles (Coleoptera: Chrysomelidae) and Comparative Performance on Poplar Foliage1,2
- Bauer, Leah S.; Nordin, Gerald L. 1989. Effects of Nosema fumiferanae (Microsporida) on Fecundity, Fertility, and Progeny Performance of Choristoneura fumiferana (Lepidoptera: Tortricidae)
- Bauer, Leah S.; Nordin, Gerald L. 1989. Response of Spruce Budworm (Lepidoptera: Tortricidae) Infected with Nosema fumiferanae (Microsporida) to Bacillus thuringiensis Treatments
- Bauer, Leah S.; Nordin, Gerald L. 1989. Response of Spruce Budworm (Lepidoptera: Tortricidae) Infected with Nosema fumiferanae (Microsporida) to Bacillus thuringiensis Treatments
- Bauer, Leah S.; Nordin, G.L. 1988. Nutritional pyhsiology of the eastern spurce budworm, Choristoneura fumiferana, infected with Nosema fumiferanae, and interactions with dietary nitrogen
- Bauer, Leah S.; Nordin, Gerald L. 1988. Pathogenicity Of Nosema fumiferanae (Thomson) (Microsporida) In Spruce Budworm, Choristoneura Fumiferana (Clemens), And Implications Of Diapause Conditions
- Lorimer, Nancy; Bauer, Leah S. 1983. Reproductive compatibility within and among spruce budworm (Lepidoptera: tortricidae) populations
- Lorimer, Nancy; Bauer, Leah S. 1983. Spruce budworm weight and fecundity: means, frequency distributions, and correlations for two populations (Lepidoptera: tortricidae)
Last Modified:
11/19/2008