Dr. Ellen YergerContact Information
Office Hours
Faculty Website


Postdoctoral Scholar, Pennsylvania State University
PhD Entomology, University of Illinois, Urbana-Champaign
MS Chemistry, University of Illinois, Urbana-Champaign
BS Biology (Honors), Union College, Schenectady NY


Entomology, Insect Plant Interactions


  • BIOL 201 Ecology and Evolution
  • Ellen Yerger with DNA kitBIOL 202 Cell and Molecular Biology
  • BIOL 203 Genetics and Development
  • BIOL 240 Human Physiology
  • BIOL 420/520 Entomology Principles and Practice
  • BIOL 681 Contemporary Environmental Concerns


Insect Plant Interactions, Insect Response to Invasive Plants, Biological Invasions, Chemical Ecology.

Current Research Projects

Characterization of invasive plant impact on insect populations, and trophic ricochet effects. Ellen Yerger with student.

Determination of the identity and extent of Arbuscular Mycorrhizal Fungi (AMF) symbiosis on native and invasive plants.

Biological control by the predatory beetle, Laricobius nigrinus, on Hemlock Wooly Adelgid (HWA) in hemlock forests


Kong, L., X. Chen, E.H. Yerger, Q. Li, F. Chen, H. Xu, F. Zhang. 2021. Arbuscular mycorrhizal fungi enhance the growth of the exotic species Ambrosia artemisiifolia. Journal of Plant Ecology. 

Zhang, Fengjuan, Qiao Li, Ellen Heininger Yerger, Xue Chen, Qing Shi, Fanghao Wan. 2018. AM fungi facilitate the competitive growth of two invasive plant species, Ambrosia artemisiifolia and Bidens pilosa. Mycorrhiza 28(8): 703-715. DOI: 10.1007/s00572-018-0866-4.

Godfrey, Rebekah K., Ellen H. Yerger, Tim J. Nuttle. 2018. Opposing deer and caterpillar foraging preferences may prevent reductions in songbird prey biomass in historically overbrowsed forests. Ecology and Evolution 8: 560-571.

Chips, Michael J., Ellen H. Yerger, Arpad Hervanek, Tim Nuttle, Alejandro A. Royo, Jonathan N. Pruitt, Terrence P. McGlynn, Cynthia L. Riggall, and Walter P. Carson. 2015. The Indirect Impact of Long-Term Overbrowsing on Insects in the Allegheny National Forest Region of Pennsylvania. Northeastern Naturalist 22(4): 782-797.

Wheatall, L., T. Nuttle, and E.H. Yerger. 2013. Indirect effects of
pandemic deer overabundance inferred from caterpillar-host relations.
Conservation Biology 27(5): 1107-1116.

Yerger, E. H. 2013. Student perspectives on introductory biology labs designed to develop relevant skills and core competencies. In: Robert E. Yager, editor. Exemplary College Science Teaching. National Science Teachers Association Press. pp. 75-89.

Dr. Yerger Research

Nuttle, T., E. H. Yerger, S. H. Stoleson, and T. E. Ristau. 2011. Legacy of top-down herbivore pressure ricochets back up multiple trophic levels in forest canopies over 30 years. Ecosphere 2: 1-11.

Yerger, E.H. 2008. Assessments that Assist in Motivating Students. In: Linda W. Crow, Donald French, and Tom Lord, editors. College Science Teacher's Guide to Assessment. National Science Teachers Association Press. pp.151-153.

Yerger, E.H., and M.C. Rossiter. 1996. Natural causes and rates of early larval mortality in gypsy moths (Lepidoptera: Lymantriidae) sampled from field populations in different density states. Environmental Entomology 25: 1002-1011.

Dr. Yerger DataGrazzini, R., D. Hesk, E. Yerger, D. Cox-Foster, J. Medford, R. Craig, R.O. Mumma. 1995. Species distribution of biochemical and morphological characters associated with small pest resistance in Pelargonium xhortorum. J. Amer. Soc. Hort. Sci. 120(2): 336-342.

Grazzini, R., D. Hesk, E. Yerger, D. Cox-Foster, J. Medford, R. Craig, R.O. Mumma. 1995. Distribution of anacardic acids associated with small pest resistance among cultivars of Pelargonium xhortorum. J. Amer. Soc. Hort. Sci. 120(2): 343-346.

Mumma, R.O., R. Craig, D. Cox-Foster, J. Medford, H. Grossman, R. Grazzini, D. Hesk, D. Walters, E. Yerger. 1992. Biochemistry and Genetics of Small Arthropod Resistance in Pelargonium. In R. Craig and J. Selchau, eds., Proceedings of the Third International Geranium Conference. Ball Publishing, Geneva, IL.

Mumma, R.O., R. Craig, D. Cox-Foster, J. Medford, R. Grazzini, E. Yerger, D. Hesk. 1992. Chemistry, Morphology, and Genetics of Small Pest Resistance in Geraniums. In J.A. Garbarino and P. Fiedler, eds., Actas: 1er Simposio Internacional Quimica de Productos Naturales y sus Aplicaciones. Division Quimica de Productos Naturales, Sociedad Chilena de Quimica, publisher. pp. 45-59.

Yerger, E.H., R.A. Grazzini, D. Hesk, D.L. Cox-Foster, R. Craig and R.O. Mumma. 1992. A Rapid Method for Isolating Glandular Trichomes. Plant Physiol. 99: 1-7.

Grazzini, R.A., E. Yerger, D. Hesk, D. Cox-Foster, J. Medford, R. Craig, and R.O. Mumma. 1991. Glandular trichome-specific lipid composition of geranium (abstract no. 711). HortScience 26: 167.

Grazzini, R.A., D. Hesk, E. Yerger, C.C. Reddy, G. Hildenbrandt, J. Medford, D. Cox-Foster, R. Craig, and R.O. Mumma. 1991. Inhibition of prostaglandin endoperoxide synthase and lipoxygenase by anacardic acids (abstract no. 694). HortScience 26: 165.

Grazzini, R., D. Hesk, E. Heininger, G. Hildenbrandt, C. C. Reddy, D. Cox-Foster, J. Medford, R. Craig, and R.O. Mumma. 1990. Inhibition of lipoxygenase and prostaglandin endoperoxide synthase by anacardic acids. Biochem. Biophys. Res. Commun. 176: 775-780.

Heininger, E.E. 1989. Effects of furocoumarin and furoquinoline allelochemicals on host plant utilization by Papilionidae. PhD thesis. University of Illinois at Urbana-Champaign, Urbana IL. Under the direction of May R. Berenbaum.

Tuveson, R.W., M.R. Berenbaum, and E.E. Heininger. 1986. Inactivation and mutagenesis by phototoxins using Escherichia coli strains differing in sensitivity to near- and far- ultraviolet light. J. Chem. Ecol. 12: 933-948.