Tonya Bittner
Research Associate, Natural Resources and the Environment

I’ve always been interested in the ecology and evolution of animal populations; my early interest was color variation in snakes. I enjoy using molecular tools and manipulative experiments. At Cornell, I have worked with invasive insects, their pathogens, symbionts, and predators. These include a wood borer (Sirex noctilio), a defoliator (Lymantria dispar), and a plant-sucking insect (Adelges tsugae), all attacking North American trees. The complex ecological interactions of forest invasives are fascinating and understanding them is necessary for management efforts. As a Research Associate in the New York State Hemlock Initiative (NYSHI), I work with classical biological control agents of the invasive hemlock woolly adelgid (HWA, Adelges tsugae), an introduced pest infesting eastern and Carolina hemlock trees in North America, frequently causing tree mortality.
Education
- PhD in Biological Sciences, Northern Illinois University, 2000
- BA in Biology, North Central College, 1993
Recent Research
My current research on two predatory flies in the genus Leucotaraxis (formerly Leucopis) is part of a collaborative effort across the eastern US to establish biological control of the hemlock woolly adelgid. The small but mighty fly larvae puncture and drain prey eggs, often displacing adult HWA from the feeding site, thus killing the adults as well. I collaborated on a genetic survey of North American Leucotaraxis lineages to better understand their evolutionary history and distributions. Recently I finished rearing hundreds of flies at different temperatures to produce models of development rates. These will inform predictive models of predator population phenology and population growth across the range of eastern hemlocks. I am also leading a team developing species-specific environmental DNA (eDNA) sampling approaches in the forest, to detect activity of biocontrol predators and for early detection of the pest. You can find all of our lab’s publications on our website.
Selected Publications
Havill NP, Bittner TD, Andersen JC, Dietschler NJ, Elkinton JS, Gaimari SD, Griffin BP, Zembrzuski D, Whitmore MC (2023). Prey-associated genetic differentiation in two species of silver fly (Diptera: Chamaemyiidae), Leucotaraxis argenticollis and L. piniperda. Insect Systematics and Diversity 7(3), https://doi.org/10.1093/isd/ixad007
Bittner TD, Havill NP, Caetano IAL, Hajek AE (2019) Efficacy of Kamona strain Deladenus siricidicola nematodes for biological control of Sirex noctilio in North America and hybridisation with invasive conspecifics. NeoBiota 44:39-55. doi:10.3897/neobiota.44.30402
- Bittner TD, Hajek AE, Liebhold AS, Thistle H (2017) Modification of a pollen trap design to capture airborne conidia of Entomophaga maimaiga and detection of conidia by quantitative PCR. Applied and Environmental Microbiology 83(17) https://doi.org/10.1128/AEM.00724-17
- Bittner TD, Hajek AE, Haavik L, Allison J, Nahrung H (2017) Multiple introductions of Sirex noctilio (Hymenoptera: Siricidae) in northeastern North America based on microsatellite genotypes, and implications for biological control. Biological Invasions, doi:10.1007/s10530-016-1365-1
Contact Information
B31 Morrison Hall
Ithaca, NY 14853
tdb68 [at] cornell.edu
Additional Links