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Heath MacMillan

Associate Professor

Current Research

Environmental stressors set limits to animal performance (e.g. movement, growth, and reproduction) and thereby limit fitness. These effects of stressors are all mediated through molecular biology, biochemistry, and physiology. If we want to fully understand the impacts of stressors on animal distribution and abundance, or plan for the best ways to mass rear animals, we need to understand the mechanisms of stress tolerance.

In the MacMillan Lab, we study how and why different variables in an animal’s environment, like extreme temperatures, plastic pollution, or diet, set limits to individual performance and survival, and how differences in tolerance to these stressors among individuals, populations, and species arise. To do this, we use several insects as models, like crickets, fruit flies, and mosquitos.

By integrating observations at the molecular, cellular, tissue, organ, and whole animal levels we build and test conceptual models that can explain performance. Using these models as a backbone for new questions, we study the mechanisms that allow for the wide variation in performance and fitness we observe among individuals, populations, or species in nature.

Heath welcomes inquiries from talented and motivated scientists looking to start a project on insect physiology, biochemistry, and/or molecular biology. See the lab website for details on available positions.

Selected Publications

Cheslock, A., Provencher, J., Campeau, W., MacMillan, H.A. (2025) The impact of microplastics on tissue-specific gene expression in the tropical house cricket, Gryllodes sigillatus. Environmental Pollution 381: 126475.

Kong, J.D., Vadboncoeur, E. Bertram, S.M., MacMillan, H.A. (2025) Temperature-dependence of life history in an edible cricket: Implications for optimising mass rearing. Current Research in Insect Science 7, 100109.

Kasdorf, S.Y., Muzzatti, M.J., Haider, F., Bertram, S.M., MacMillan H.A. Brewery waste as a sustainable protein source for the banded cricket (Gryllodes sigillatus). Journal of Insects as Food and Feed 11(8): 1417-1429.

Andersen, M.K., Roe, A.D., Liu, Y., Musso, A.E., Fudlosid, S., Haider, F., Evenden, M.L, MacMillan, H.A. (2024). The freeze-avoiding mountain pine beetle (Dendroctonus ponderosae) survives prolonge exposure to stressful cold by mitigating ionoregulatory collapse. The Journal of Experimental Biology 227, jeb247498.

Ritchie, M.W., Provencher, J.F., Allison, J.E., Muzzatti, M.J., MacMillan, H.A. (2024) The digestive system of a cricket pulverizes polyethylene microplastics. Environmental Pollution 343: 123168.

Carrington, J., Andersen, M.K., Brzezinski, K., MacMillan, H.A. (2020) Hyperkalemia, not apoptosis, accurately predicts chilling injury in individual locusts. Proceedings of the Royal Society B: Biological Sciences. 287: 20201663.

Full list of publications