George Heimpel

Principal Investigator

George Heimpel, [email protected]

I'm primarily a parasitoid ecologist and interested in biological control solutions to pest and weed problems in agricultural and natural systems.  I teach classes in Insect Behavior and Biological Control and enjoy working with students, post-docs and other collaborators to better understand the interactions that underlie safe and effective biological control. Current projects include classical and conservation biological control of the soybean aphid in the United States, classical biological control of a parasite of Darwin’s finches in the Galapagos Islands, and classical biological control of the imported cabbageworm in the United States. More generally, interests in the lab focus on aspects of host specificity in parasitoids, indirect interactions in natural and agricultural systems, sex determination in parasitoid wasps, evolution of parasitoid reproductive strategies, and ecosystem services (biological control) associated with biofuel cropping systems.

Post-doctoral Researchers


Pamela Rueda-Cediel

Pamela Rueda-Cediel, Ph.D (2015). [email protected]

I am a quantitative ecologist and modeler focused on the protection of species of conservation concern. My research area lies at the intersection of population dynamics, conservation biology, ecological risk assessment and decision theory. Currently, I am developing a model for Philornis downsi, an invasive parasitic fly that is decreasing the viability of the iconic Darwin finches in the Galapagos Islands, and a model for Conura annulifera, a natural enemy of P. downsi in mainland Ecuador, as a biological control agent in the Galapagos Islands. Characterizing the host-parasitoid dynamics between P. downsi and C. annulifera across habitats with different bird composition is crucial to the management plans for Darwin finches in the Galapagos.

Graduate Students

Alyssa Gooding

Alyssa Gooding (2020), Ecology, Evolution & Behavior. [email protected]





Mary Marek-Spartz

Mary Marek-Spartz (2017), Entomology. [email protected]

My research focuses on biological control of invasive plants through the agency of imported natural enemies. The goal is to use herbivores to combat noxious weeds, especially when other methods of suppression are not effective. I am currently working on the garlic mustard (Alliaria petiolata) biocontrol effort, researching two Ceutorhynchus weevils from the plant's native range in Europe. I am interested in modeling herbivore-plant interactions and potential species distribution in novel areas prior to release. I have a background in spatial modeling and a Master's of Geographic Information Science from Saint Mary's University of Minnesota.


Ismael Ramirez

Ismael Ramirez (2016), Entomology. [email protected]

I am interested in biological control as a possible solution to control introduced species for conservation purposes; parasitic hymenopteran species are especially promising biological control agents. I am also interested in host range specificity studies as a tool for understanding the risks and benefits of a potential biological control program. I am currently working with a promising biological control agent, the chalcidid wasp Conura annulifera to control the invasive parasitic fly Philornis downsi, in hopes of protecting Darwin's finches in the Galapagos Islands.


Jonathan Dregni in a Minnesota soybean field.

Jonathan Dregni, M.S. (2020), Entomology. [email protected]

I am interested in agriculture as an arena for ecology experiments, and am asking whether chemical pest control affects biological control in Minnesota soybean fields; specifically, what effects do neonicotinoid seed treatments have on Aphelinus certus, a biological control agent which targets soybean aphid? I have also worked in the quarantine lab, testing the host range of potential biological control parasitoids. When not caring for insect colonies I manage the Heimpel lab, raise my children, and teach Pilates and t'ai chi ch'uan.
Charlie Lehnen

Charles Lehnen, [email protected] 

I am interested in community ecology, and my current studies focus on the community-level interactions of Galapagos Diptera. Field-rearing protocols have revealed Dipteran interactions with various substrates, including Giant Galapagos Tortoise dung. Along with augmenting knowledge of community ecology as a whole, the goal of these studies is to inform the development of laboratory cultures of endemic/native Galapagos Diptera for specificity tests of prospective biocontrol agents targeted at the invasive passerine nare-fly Philornis downsi. I am looking forward to further understanding the interplay of species, which forms the framework of ecological systems.

Undergraduate Students

Visiting Students and Scholars, past and current

  • Miguel Calvo Agudo (2019), University of Valencia, Spain
  • Maxime Damiens (2017), University of Rennes, France
  • Lucie Monticelli (2016, 2017), University of Nice, France
  • Michele Ricupero (2017), University of Catania, Italy
  • Nicola Bodino (2015), University of Torino, Italy
  • Paula Lahuatte (2015), Charles Darwin Foundation, Galapagos, Ecuador
  • Dr. Michela Matos (2015), Visoca University, Brazil
  • Roxanne Sage (2015), University of Quebec in Rimouski, Canada
  • Matthias Senft (2015), University of Munich, Germany
  • Dr. Alejandro Tena (2015), Instituto Valenciano de Investigaciones Agrarias (IVIA), Spain
  • Clara Malloines (2012),  INRA, Nice, France. Ph.D. student, University of Texas
  • Dr. Remy Poland (2009), Ph.D. Cambridge University, U.K.
  • Dr. Ying Zhang (2008), Ph.D. Chinese Plant Protection Institute, Beijing 2010
  • Dr. Camille Delebeque (2007),  INRA, Nice, France. Ph.D. in Biology, Harvard University

Alumni: Students

  • Megan Carter, M.S. (2013), Entomology.
    • Thesis title: Functional response and the effects of insecticidal seed treatment on the soybean aphid parasitoid, Binodoxys communis.           
  • Jeremy Chacón, Ph.D. (2010), Entomology.
    • Dissertation title: Intraguild predator interference of a classical biological agent of the soybean aphid.
    • Current position: Post-doc Univ. of Minnesota.
  • Christine Dieckhoff, Ph.D. (2011), Entomology. 
    • Dissertation title: Host acceptance behavior in the soybean aphid parasitoid Bindoxys communis (Hymenoptera: Braconidae) – the role of physiological state in biological control.
    • Current position: Post-doc, USDA ARS.        
  • Annie-Eve Gagnon, Ph.D. (2010). Laval University, Québec, co-advised by Jacques Brodeur.
    • Dissertation title: Detection of intraguild predation between coccinellids using molecular analyses of gut contents and its impact on the biological control of the soybean aphid.
    • Current Position: Project director: Agriculture and Agri-Food Canada.
  • Thelma Heidel, Ph.D. (2012), Entomology. Co-advised by David Ragsdale.
    • Dissertation title: Compatibility of soybean aphid integrated pest management strategies.
    • Current position: Post-doc, Iowa State University.
  • Marlijn Hoogendoorn, Ph.D. (2003), Entomology.
    • Dissertation title: Factors influencing the abundance and predation of two coccinellid species in an agricultural system: the influence of vegetational diversity and direct and indirect interactions between species.
    • Current position: Forensic Scientist, Nuclear DNA section, Bureau of Criminal Apprehension, St. Paul, MN.
  • Cynthia Hsu, Ph.D. (2006), Entomology.
    • Dissertation title: Spatial distribution of the European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), and the response of the specialist parasitoid Macrocentrus grandii Goidanich (Hymenoptera: Braconidae) to host heterogeneity in the field.
    • Current position: post-doctoral researcher, Cornell University.    
  • Hannah Gray, Ph.D. (2020), Entomology.
    • Dissertation title: Arthropod Predation in Brassica Agroecosystems: Effects of Latitude, Community Composition, and Diet Breadth.
    • Current position: USDA-NIFA Postdoctoral Fellow, Jha Lab, Dept. of Integrative Biology, University of Texas at Austin.               
  • Matt Kaiser, Ph.D. (2017), Ecology, Evolution & Behavior.  
    • Dissertation title: Transgenerational Fecundity Compensation and Post-Parasitism Reproduction by Aphids in Response to their Parasitoids.
    • Current position: post-doctoral researcher, Iowa State University, Ames, Iowa  
  • Joe Kaser, Ph.D. (2016), Entomology.
    • Dissertation title: Risk and efficacy in biological control: an evaluation of the aphid parasitoid Aphelinus certus in North America
    • Current position: Post-doc, Rutgers University.
  • Jana Lee, Ph.D. (2004), Entomology.
    • Dissertation title: Diversifying agroecosystems with floral habitat to improve biological control.
    • Current Position: USDA-ARS research scientist, Corvallis, OR.
  • Jonathan Lundgren, Ph.D. (2000), Entomology.
    • Master's Thesis title: Trichogramma and Biological Control of Cruciferous Lepidoptera.
    • Current position: USDA-ARS research scientist; Brookings, SD.
  • Eric Middleton, Ph.D. (2020), Entomology.
    • Dissertation title: Wildflower plantings in agroecosystems: The effects on beneficial insect communities and biological control of Colorado Potato Beetle
    • Current position: post-doctoral researcher, University of Florida Citrus Research and Education Center.
  • James Rudolph Miksanek, Ph.D. (2020), Entomology.
    • Dissertation title: Population ecology of Aphelinus certus, an adventive parasitoid of soybean aphid in North America, with implications for biological control.
    • Current position: Metropolitan State University, Saint Paul, MN.
  • Emily Mohl, Ph.D. (2016), Ecology, Evolution & Behavior.
    • Dissertation title: The multi-trophic context of plant defense: ecological and evolutionary implication of variation in milkweeds.
    • Current Position: Assistant Prof. of Biology/Education at St. Olaf College, MN.

Alumni: Post-doctoral Researchers

  • Dr. Susanna Acheampong (2004-2005). Current position: Agri-Food Canada, Agassiz, British Columbia, Canada.
  • Dr. Mark Asplen (2007-2012). Current position: Associate Professor, Metropolitan State University, St. Paul, MN.
  • Dr. Antonio Biondi (2013). Current position: Assistant Professor, University of Catania, Italy.
  • Dr. Rebecca Boulton (2016, 2017). Current position: Post-doctoral Researcher, University of Exeter, Cornwall.
  • Dr. Mariana Bulgarella (2014-2016). Current position: Visiting Scholar, Victoria University of Wellington, New Zealand.
  • Dr. Jetske de Boer (2004-2006). Current position: Research Fellow, Wageningen University, The Netherlands.
  • Dr. Nicolas Desneux (2006-2007). Current position: Research Director, INRA, France.
  • Dr. Henry Fadamiro (1998-1999). Current position: Professor of Entomology, Auburn University.
  • Dr. Robert Koch (2005-2006). Current Position: Assistant Professor of Entomology, University of Minnesota.                                       
  • Dr. Dawn Olson (1998). Current position: Research Scientist at USDA-ARS in Tifton, Georgia, USA.
  • Dr. Vivian Osuji (2000-2002). Current position: International Center of Insect Physiology and Ecology, Kenya.
  • Dr. Julie Peterson (2012-2013). Current Position: Assistant Professor, University of Nebraska, North Platte, NE.
  • Dr. Milan Plećaš (2014-2015). Current position: Lecturer, Belgrade University, Serbia.
  • Dr. Zeynep Seyzen (2006-2008, 2011). 
  • Dr. Carl Stenoien (2017-2020). Current position: Data Analyst, MN Pollution Control Agency.
  • Dr. Jerome J. Weis (2014-2016).                     
  • Dr. Laura Weiser (2002-2003). Current position: Associate Professor of Biology – Texas A&M University, Central Texas; Killeen, TX.
  • Dr. Kelton Welch (2016-2017).
  • Dr. Zhishan Wu (1999-2004).                       
  • Dr. Kris Wyckhuys (2005-2007). Current position: Senior Researcher, CIAT, Vietnam.


  • Ruth Barta
  • Karen Blaedow, M.S.
  • Tony Charvoz
  • Amy Davis
  • Komala Kanagala Devi
  • Virginia Howick, Ph.D.
  • Jacqueline Nuzzo
  • Amanda Stephens, M.S.
  • Anh Tran, M.S.
  • Stefanie Wolf, M.S.

Undergraduate Researchers

  • Katy Vogt, Senior honors thesis (1998 – 1999)
  • Markeeta Keyes, McNair Minorities scholar (1999)
  • Seth Bomgren, Senior directed research (1999 – 2000)
  • Dana Gardner, Master's of Agriculture student (2001)
  • Kara Ferguson, UROP fellowship (2001)
  • Carmen Gavin, UROP fellowship (2003)
  • Jeremy Kobany, UROP fellowship (2004)
  • Daniel Barta, UROP fellowship (2006)
  • Nancy Fares, 3 Units of directed research (2007)
  • Virginia Howick, 7 Units of directed research (2008-2009)
  • Simon Lueth, 3 Units of directed research (2009)
  • Sarah Gunderson, UROP fellowship (2009)
  • Rachel Ward, LSSURP awardee from Concordia College, Moorehead, MN (2009)
  • Michael Oxendine, LSSURP awardee from South Carolina (2010)
  • Emmanuel Santa Martinez, LSSURP awardee from Puerto Rico (2010)
  • Ashlee Lang, 3 Units of directed research (2010)
  • Evan Baeten, UROP fellowship (2011)
  • Logan Fees, UROP fellowship (2011)
  • Mary Pattison, UROP fellowship (2012)
  • Mattea Allert, LSSURP awardee from U. of Wis (2012)
  • Erik Swanson, LSSURP awardee from Wheaton College (2012)
  • Andrew Cumming, Independent Research, (2014)
  • Taylor Pitel, Independent Research (2014-2015)
  • Symone McLain, UROP fellowship (2016)
  • Alex Dutchin, UROP  Fellowship (2019)
  • Sierra Baum, UROP Fellowship (2019)

Collaborators, past and current

  • Dr. David Andow, University of Minnesota
  • Dr. Jacques Brodeur, University of Montreal
  • Dr. Charlotte Causton, Charles Darwin Foundation, Galapagos, Ecuador
  • Dr. Nico Desneux, INRA, Nice, France
  • Dr. James Eckberg, Xerces Society, Minnesota
  • Dr. Keith Hopper, USDA ARS, Newark, Delaware
  • Dr. Mark Jervis, Cardiff University, Wales
  • Dr. Gregg Johnson, University of Minnesota
  • Dr. Sarah Knutie, University of South Florida
  • Dr. Jennifer Koop, University of Massachusetts
  • Dr. Doug Landis, Michigan State University
  • Dr. Matt O'Neal, Iowa State University
  • Dr. Paul Ode, Colorado State University
  • Dr. Kerry Oliver, University of Georgia
  • Dr. Martin Quiroga, Instituto de Ciencias Veterinarias del Litora, Argentina
  • Dr. David Ragsdale, Texas A&M University
  • Dr. Louise Vet, Netherlands Institute of Ecology
  • Dr. Jennifer White, University of Kentucky
  • Dr. Jim Whitfield, University of Illinois
  • Dr. Kongming Wu, Chinese Institute of Plant Protection
  • Dr. Lucia Zappala, University of Catania, Italy