My research interests and activities fall into several broad areas. All involve efforts to discern mechanisms of behavior:
- Movement and mating of western corn rootworm beetles in refuge and Bt-transgenic corn. I am currently working on a study focused on discovering how well our expectations about rootworm behavior match with what really happens when we plant refuges in Bt corn.
- Egg-laying behavior and movement/dispersal of field crop insect pests.
- Effects of diet and physiological status on activity, behavior, egg-laying and movement of rotation-resistant western corn rootworm beetles.
- Monitoring abundance of beetles in Illinois soybean fields.
- Intra- and interfield movement by WCR adults in non-transgenic refuges and transgenic corn.
- Contribution of WCR gut physiology to evolution and spread of rotation-resistant WCR.
- Impact of proposed biomass crops on behavior and ecology of key field crop pests.
- Ecology and movement of noisy prairie insects.
My approach to the study of insects is colored by an abiding interest in behavior and an appreciation for the constraints physiology can impose on behavior. In my experience, direct observation of insects is necessary to truly understand their impact on our world; knowing what happened to produce a result is all the more valuable when we know how it happened as well.
My current research focuses on the behavioral, physiological, and ecological mechanisms that underlie western corn rootworm (WCR) resistance to crop rotation. I am particularly interested in the role of diet and reproductive behavior on short and long-distance movement of WCR adults within and between fields. These studies currently focus on assessing movement of mate-seeking WCR males from refuges into transgenic portions of cornfields and the likelihood than refuge males actually mate with potentially resistant WCR females that emerged from transgenic corn. Testing assumptions about the design and functioning of refuges for insect resistance management (IRM) in transgenic crops contributes to their improved design and sustainable deployment.
I am also currently evaluating a method to measure and study rotation-resistant WCR activity that uses evidence of soybean herbivory. This project is testing a new method to monitor rotation-resistant WCR activity. If successful, it could be adapted for grower use as a quick tool to measure the local risk of WCR economic larval injury in rotated corn.
I remain fascinated by the synergy between host specific chemical stimuli and other features like epicuticular waxes and physical characteristics which stimulate host-oriented behaviors of many insects.
I believe that a willingness to sometimes let your insect subject lead the way is a trait which all behaviorists share, and that it is a prerequisite for discovery. If we are patient enough to listen, insects will not fail to tell us amazing stories.
PhD, Entomology, Michigan State University, 1994
MS, Entomology, Michigan State University, 1990
BS, Biological Sciences, Michigan State University, 1987
Awards and Honors
Recipient of the College of Agricultural, Consumer and Environmental Sciences 2003 Team Award for Excellence as a member of the Western Corn Rootworm Research Group
Additional Campus Affiliations
Principal Insect Behaviorist, Illinois Natural History Survey
Adjunct Assistant Professor, Entomology
Adjunct Assistant Professor, Crop Sciences
Spencer, J. L., & Hughson, S. A. (2022). Insect resistance to crop rotation. In D. W. Onstad, & L. M. Knolhoff (Eds.), Insect Resistance Management: Biology, Economics, and Prediction (3 ed., pp. 191-244). Academic Press. https://doi.org/10.1016/B978-0-12-823787-8.00014-3
Spencer, J. L., Mabry, T. R., Levine, E., & Isard, S. A. (2021). Soybean Foliage Consumption Reduces Adult Western Corn Rootworm (Diabrotica virgifera virgifera)(Coleoptera: Chrysomelidae) Survival and Stimulates Flight. Journal of economic entomology, 114(6), 2390-2399. https://doi.org/10.1093/jee/toab167
Coyle, D., Brosius, T., Devries, Z., Schmidt-Jeffris, R., Gott, R. C., Loudon, C., Saguez, J., Simonsen, T., Van Den Berg, J., McDonnell, R., Ronai, I., Zhu, L., Siebert, M., Wessels, F., Hamm, R., Higgins, L., Thompson, S., Serikawa, R., Spomer, N., & Spencer, J. L. (2020). COVID-19: Reflections from Entomologists Who Rose to the Occasion. American Entomologist, 66(3), 34-41. https://doi.org/10.1093/ae/tmaa040
Spencer, J. L. (2020). Getting High with the Beetles. American Entomologist, 66(4), 28-32. https://doi.org/10.1093/ae/tmaa058
Spencer, J. L., & Orellana, L. R. (2020). Western corn rootworm (Diabrotica virgifera virgifera LeConte) (Coleoptera: Chrysomelidae) oviposition can be released by decapitation. Journal of Applied Entomology, 144(6), 534-541. https://doi.org/10.1111/jen.12756