Rosemarie De Clerck-Floate, Ph.D.

Image Rosemarie De Clerck-Floate
Research Scientist - Weed Biological Control

Research on:

- Biological control of weeds

- Plant-insect interactions

- Insect and plant ecology


Current research and/or projects

  • Effects of soil moisture and nitrogen (climate change) on efficacy of weed biological control

  • Development of release strategies for predictable establishment and impact of weed biocontrol agents

  • Development of methods for biocontrol agent mass-production

  • Assessment of biological control safety and efficacy via studies of insect-plant ecological and evolutionary associations, insect and plant behaviour, insect impact on plant individuals and populations

Research and/or project statements

Biological control is a valuable tool in the mitigation of agricultural and environmental impacts from pest threats such as weeds. When effective, the strategy provides a sustainable, long-term and low-cost solution to pest management, especially in areas where chemical control may be unfeasible for economic and/or environmental reasons (e.g., weed control on native rangelands). Canada is seen as a world leader in the discovery, development and safe use of biological control agents for weeds, and since the AAFC program’s initiation in 1951, has produced several notable successes. Our program partners with regional governments, industry (cattle producers), academia, and international experts (e.g. CABI) in the assessment, release, and knowledge development for new biocontrol agents against emerging weed problems in Canada.

Professional activities / interests

  • Adjunct Professor, University of British Columbia - Okanagan

  • Adjunct Professor, University of Lethbridge

  • President, Entomological Society of Canada (2013)

  • Member, AAFC National Containment, Biosafety and Biosecurity Committee

  • Member, AAFC Biological Control Working Group

  • Student training

  • Science and art collaborations

Education and awards

  • Ph.D. (Botany/Entomology) – Northern Arizona University

  • M.Sc. (Biology) - University of Saskatchewan

  • B.Sc. (Biology) – Laurentian University

  • Federal Government 5-NR Science Award for Leaders in Sustainable Development (with R. Bourchier )for Weed Biocontrol Research 2001

International experience and/or work

  • Scientific Advisor – International weed biological control projects (e.g. toadflax, houndstongue, hawkweeds).

  • Transfer of Work (weed biological control)– CSIRO Brisbane, Australia (2004 – 2005)

Key publications

  1. Moffat, C.E., R.S. Bourchier, R.A. De Clerck-Floate, P.G. Mason, and D.J. Ensing. 2021. How do we know biocontrol agents are safe? An overview of the Canadian research and regulatory process for new biocontrol agents. British Columbia Invasive Species Council. Invasives 2021 Conference (virtual). 9 Februrary, 2021.

    2021 - View publication details

  2. Ensing, D.J., R. Bourchier, R. De Clerck-Floate, T.D. Nelson, V. Miller, S. Turner, C.E. Moffat. 2020. Classical biological control leads to long term declines in the rangeland invasive spotted knapweed. Entomological Society of America (virtual), 16-19 November, 2020.

    2020 - View publication details

  3. Ensing, D.J., T.D. Nelson, R. Bourchier, R. De Clerck-Floate, V. Miller, S. Turner, C.E. Moffat. 2020. Contemporary ecology of historical weed biological control programs: Re-evaluating spotted knapweed biocontrol in BC. Entomological Society of British Columbia (virtual), 26-28 October, 2020.

    2020 - View publication details

  4. De Clerck-Floate, R. 2019. Weevils from Serbia show promise in yellow toadflax biological control in Canada. Agriculture and Agri-Food Canada, Lethbridge, Alberta, Canada. Catalogue No. A22-631/2019E-PDF, ISBN No.978-0-660-32854-6, AAFC No. 12990E. 4 pp.

    2019 - View publication details

Research facility

5403 1st Avenue South
Lethbridge, AB T1J 4B1


  • Member, Entomological Society of Canada

  • Member, Entomological Society of Alberta

  • Member, Canadian Botanical Association

  • Member, Entomological Society of America

  • Member, Canadian Society of Ecology and Evolution