Ann Hajek

Professor Emerita, Department of Entomology

Ann Hajek completed her PhD in Entomology at the University of California, Berkeley, and then moved to Ithaca and conducted research in the Boyce Thompson Institute on Cornell campus for 10 years. In 1994, she accepted a position as a professor, with the goal of conducting both research and teaching, in the Department of Entomology at Cornell University.

Dr. Hajek has authored or co-authored over 300 publications, including 2 books that she’s written, 4 books she’s edited and many book chapters. Throughout her career, a plethora of diverse invasive insects have been attacking and threatening North American forests and vegetable crops. Dr. Hajek has researched the associations of these invasive insects with microbes, often working on understanding their interactions and population dynamics, toward developing methods for environmentally safe control. Dr. Hajek’s research has involved many international collaborations, especially including numerous years of research on Asian longhorned beetle in China and five years as a visiting professor at the University of Copenhagen.

Throughout her 30 years at Cornell, Dr. Hajek has been involved in training graduate students and teaching undergraduates, with more than 200 people having spent time as part of her research group.

Education

BS, MS and PhD University of California, Berkeley

Recent Research

Research emphasis has focused on insect-microbial interactions, emphasizing entomopathogens but also investigating symbionts and vectored microbes
Insect species researched have been diverse invasive species, with a goal of understanding these pests in introduced environments, toward potential identification of environmentally safe methods for their control
Studies have expanded knowledge about the biodiversity of pathogens infecting insects, including some pathogens that change the behavior of hosts
Dr. Hajek and her research group have emphasized learning about the ecology of diseases caused by insect pathogens, to improve understanding and predictability of disease outbreaks

Selected Peer-Reviewed Publications (2013-2022):

Hajek, A.E., Scott, K., Sanchez-Pena, S., Tkaczuk, C., Lovett, B., Bushley, K. 2025. Annotated checklist of arthropod-pathogenic species in the Entomophthoromycotina (Fungi: Zoopagomycota) in North America. MycoKeys 114: 329-366.
Hajek, A.E., Everest, T.A., Clifton, E.H. 2023. Accumulation of fungal pathogens infecting the invasive spotted lanternfly, Lycorma delicatula. Insects 14: 912.
Fuller, A.K., Augustine, B., Clifton, E.H., Hajek, A.E., Blumental, A., Beese, J., Hurt, A., Brown-Lima, C.J. 2024. Effectiveness of dogs and humans at detecting invasive spotted lanternfly in vineyards and forests using occupancy models. Ecosphere 15: e70113.
Sacco, N.E., Hajek, A.E. 2023. Diversity and breadth of host specificity among arthropod pathogens in the Entomophthoromycotina. Microorganisms 11: 1658.
Clifton, E.H., Castrillo, L.A., Jaronski, S.T., Hajek, A.E. 2023. Cryptic diversity and virulence of Beauveria bassiana recovered from Lycorma delicatula (spotted lanternfly) in eastern Pennsylvania. Frontiers in Insect Science: Focus on Spotted Lanternfly 3: 1127682.
Gryganskyi, A.P., Golan, J., Hajek, A.E. 2022. Season-long infection of diverse hosts by the entomopathogenic fungus Batkoa major. PLOS ONE 17(5): e0261912.
Liebhold, A.M., Hajek, A.E., Walter, J.A., Haynes, K.J., Elkinton, J., Muzika, R.-M. 2022. Historical change in the outbreak dynamics of an invading forest insect. Biological Invasions 24: 879-889.
Hajek, A.E., Diss-Torrance, A.L., Siegert, N.W., Liebhold, A.M. 2021. Inoculative releases and natural spread of the fungal pathogen, Entomophaga maimaiga (Entomophthorales: Entomophthoraceae), into U.S. gypsy moth (Lepidoptera: Erebidae) populations. Environmental Entomology 50: 1007-1015.
Clifton, E.H., Castrillo, L.A., Gryganskyi, A., Hajek, A.E. 2019. A pair of native fungal pathogens drives decline of a new invasive herbivore. Proceedings of the National Academy of Science, USA 116 (19): 9178-9180.
Elkinton, J.S., Bittner, T.D., Pasquarella, V.J., Boettner, G.H., Liebhold, A.M., Gould, J.R., Faubert, H., Tewksbury, L., Broadley, H.J., Havill, N.P., Hajek, A.E. 2019. Relating aerial deposition of Entomophaga maimaiga conidia to mortality of gypsy moth (Lepidoptera: Erebidae) larvae and nearby defoliation. Environmental Entomology 48: 1214-1222.
Hajek, A.E., Henry, J.C., Standley, C.R., Foelker, C.J. 2017. Comparing functional traits and abundance of invasive versus native woodwasps. Neobiota 36: 39-55.
Hajek, A.E., van Nouhuys, S. 2016. Interactions among fatal diseases and parasitoids driven by density of a shared host. Proceedings of the Royal Society, B 283: 20160154.
Hajek, A.E., Hurley, B.P., Kenis, M., Garnas, J.R., Bush, S.J., Wingfield, M.J., van Lenteren, J.C., Cock, M.J.W. 2016. Exotic biological control agents: a solution or contribution to arthropod invasions? Biological Invasions 18: 953-969.
Fisher, J.J., Hajek, A.E. 2015. Maternal exposure of a beetle to pathogens protects offspring against fungal disease. PLoS ONE 10(5): e0125197.
Morris, E.E., Hajek A.E. 2014. Eat or be eaten: Fungus and nematode switch off as predator and prey. Fungal Ecology 11: 114-121.
Hajek, A.E., Nielsen, C., Kepler, R., Long, S.J., Castrillo, L. 2013. Fidelity among Sirex woodwasps and their fungal symbionts. Microbial Ecology 65: 753-762.

Awards & Honors

2024 Honorary Member, Society for Invertebrate Pathology (highest award for a senior member of this society)

2023 Honorary Award, International Organization for Biological Control, Nearctic Regional Section (highest award for a senior member of this section)

2019 Outstanding Accomplishments in Research, College of Agriculture and Life Sciences, Cornell University, (one research award is given by the college each year)

2018 Fellow, Entomological Society of America

2015 L. O. Howard Distinguished Achievement Award, Eastern Branch Entomological Society of America

2011 Distinguished Scientist Award, International Organization of Biological Control, Nearctic Regional Section

2011-16 Honorary Professor in Zoology, Department of Agriculture and Ecology, Faculty of Life Sciences, University of Copenhagen

2011-12 Velux Visiting Professor 2 years, University of Copenhagen (supported by the Villum Foundation)

2004 SUNY Chancellor's Award for Excellence in Scholarship

Courses Taught

Bugs in Bugs: The World of Pathogens, Symbionts and Vectored Microbes
Invasions: Trading Species in a Shrinking World
Ecology and Evolution of Infectious Disease
Invertebrate Pathology
Natural Enemies: An Introduction to Biological Control

Contact Information

6142 Comstock Hall

aeh4 [at] cornell.edu

Ann in the news

Cornell Cooperative Extension and New York State Integrated Pest Management are setting and monitoring traps at high traffic areas where the spotted lanternflies are most likely to appear.

News

July 26, 2022

Cornell partners with NYS to fight the spotted lanternfly

The devastating spotted lanternfly’s spread to upstate and western New York is not a matter of if, but when, experts say – and Cornell is a key player in helping slow the infestation.

Cornell Cooperative Extension
Cornell Integrated Pest Management
Department of Entomology

News

July 1, 2020

Cornell Atkinson awards $1.1M to innovative projects

The Cornell Atkinson Center for Sustainability has awarded seven Academic Venture Fund (AVF) interdisciplinary seed grants, totaling $1.1 million, for projects that engage faculty from eight Cornell colleges and 16 academic departments. In its...

Cornell Atkinson
Lab of Ornithology
Biological and Environmental Engineering