Prof. Julie Coetzee

Aquatic Weeds Programme Manager

Julie profile

Prof Julie Coetzee is currently the Deputy Director of the Centre for Biological Control at Rhodes
University in South Africa and the President of the Entomological Society of Southern Africa -

Prof Coetzee research focuses on understanding the interactions between freshwater aquatic plants and insects and applying this knowledge to develop sustainable management strategies for invasive species in aquatic ecosystems. Her work has been instrumental in developing biological control programs for water hyacinth and water lettuce in South Africa and other regions. In recognition of her contributions to the field, Prof Coetzee has been awarded the prestigious DSI/NRF SARChI Tier 1 Chair in Biological Control and Freshwater Alien Invasive Species Management, which she shares with Rhodes University. Her innovative research and dedication to preserving aquatic ecosystems make her a leader in her field.

In recent years, Prof Coetzee has shifted her research focus from floating aquatic plants to
submerged and emergent species. This change in focus is driven by the success of biological control programs in managing floating aquatic plants such as water hyacinth and water lettuce, which has opened up new habitats for other invasive species to thrive. These new invasive species, including submerged and emergent plants, pose a significant threat to indigenous aquatic flora and fauna, and tackling them is a complex challenge.

Research interests

  • Biological control of weeds
  • Plant-insect interactions
  • Invasion biology
  • Insect thermal ecology
  • Aquatic plant ecology
  • Biostatistics


Recent Publications

1. Minuti, G., Stiers, I. and Coetzee, J.A., 2022. Climatic suitability and compatibility of the invasive Iris pseudacorus L. (Iridaceae) in the Southern Hemisphere: Considerations for biocontrol. Biological Control, 169, p.104886.

2. Smith, R., Coetzee, J.A. and Hill, M.P. 2022. Best of both worlds: The thermal physiology of Hydrellia egeriae, a biological control agent for the submerged aquatic weed, Egeria densa in South Africa. BioControl.

3. Goddard, M., Owen, C.A., Martin, G. and Coetzee, J.A., 2022. The thermal physiology of Lysathia sp.(Coleoptera: Chrysomelidae), a biocontrol agent of parrot’s feather in South Africa, supports its success. Biocontrol Science and Technology

4. Motitsoe, S.N, Hill, J.M., Coetzee, J.A & Hill, M.P. 2022. Invasive alien aquatic plant species management drives aquatic ecosystem community recovery: An exploration using stable isotope analysis. Biological Control 173, 104995.

5. Coetzee, J.A., Paper, M.K., Miller, B.E., Kinsler, D., Cilliers, C.J. & Hill, M.P. 2022. Into Africa: Salvinia minima Baker (Salviniaceae) invades South Africa. Bioinvasions Records 11: 1011–1018.

6. Coetzee, J.A., Miller, B.M., Kinsler, D., Sebola, K. & Hill, M.P. 2022. It's a numbers game: Inundative biological control of water hyacinth (Pontederia crassipes) yields success at a high elevation, hypertrophic impoundment in South Africa. Biocontrol Science and Technology 32: 1302-1311.

6. Wansell, S.N.L., Geerts, S. & Coetzee, J.A. 2022. Where are the seeds? Lack of floral morphs limit invasion by the tristylous Pontederia cordata in South Africa. Ecology and Evolution 12 e9366. 

7. Misteli, B., Pannard, A., Aasland, E., Harpenslager, S.F., Motitsoe, S., Thiemer, K., Llopis, S., Coetzee, J., Hilt, S., Köhler, J. and Schneider, S.C., 2023. Short-term effects of macrophyte removal on aquatic biodiversity in rivers and lakes. Journal of Environmental Management, 325, p.116442.

8. Thiemer, K, Immerzeel, B, Schneider, S, Sebola, K, Coetzee, J, Baldo, M, Thiebaut G, Hilt, S, Köhler, J, Harpenslager, S-F, Vermaat, J.E. 2023. Integrating aquatic plant nuisance perception into a probabilistic management decision tool. Environmental Management, 71, 1024–1036.

9. Nqayi, S.B., Zachariades, C., Coetzee, J.A., Hill, M.P., Chidawanyika, F., Uyi, O., McConnachie, A. 2023. Do thermal requirements of Dichrorampha odorata, a shoot-boring moth for the biological control of Chromolaena odorata explain its failure to establish in South Africa? African Entomology, 31: e13597.

10. Paper, M.K., Righetti, T., Raubenheimer, S.L., Coetzee, J.A., Sosa, A.J., and Hill, M.P. 2023. Effects of elevated CO 2 on feeding responses of biological control agents of Pontederia crassipes. Entomologia Experimentalis et Applicata, 00: 1– 11.

11. Britton, J.R., Lynch, A.J., Bardal, H., Bradbeer, S.J., Coetzee, J.A., Coughlan, N.E., Dalu, T., Tricarico, E., Gallardo, B., Lintermans, M. and Lucy, F., 2023. Preventing and controlling nonnative species invasions to bend the curve of global freshwater biodiversity loss. Environmental Reviews. e-First

12. Gervazoni, P., Minuti, G., Fuentes-Rodriguez, D., Coetzee, J., Sosa, A., Sabater, L. and
Franceschini, C., 2023. Citizen science improves the known and potential distribution of a strong wetland invader: implications for niche modeling and invasion management. Environmental Management 71: 1176-1187.

13. Miller, B., Coetzee, J. and Hill, M., 2023. Evaluating the establishment of a new water hyacinth biological control agent in South Africa. African Entomology, 31.

14. Mnciva, S.T., Coombes, C. and Coetzee, J.A., 2023. Morphological and molecular
characterisation of naturally occurring pathogenic fungi for Pontederia crassipes (water hyacinth) in South Africa. Biocontrol Science and Technology, 33(9), 869-884.

15. Minuti, G., Coetzee, J.A. and Stiers, I., 2023. Contrasting effects of climate change on the invasion risk and biocontrol potential of the invasive Iris pseudacorus L. between Northern and Southern Hemisphere. Biological Control, 184, 105290.

15. Reid, M.K., Paterson, I.D., Coetzee, J.A., Gettys, L.A. and Hill, M.P., 2023. Know thy enemy: Investigating genetic contributions from putative parents of invasive Nymphaea mexicana hybrids in South Africa as part of efforts to develop biological control. Biological Control, 184, 105291.

16. Paterson, I.D., Motitsoe, S.N., Coetzee, J.A. and Hill, M.P., 2023. Recent post-release evaluations of weed biocontrol programmes in South Africa: a summary of what has been achieved and what can be improved. BioControl, pp.1-13.

17. van Steenderen, C.J., Sutton, G.F., Owen, C.A., Martin, G.D. and Coetzee, J.A., 2023. Sample size assessments for thermal physiology studies: An R package and R Shiny application. Physiological Entomology.

18. Thiemer, K., Immerzeel, B., Schneider, S., Sebola, K., Coetzee, J., Baldo, M., Thiebaut, G., Hilt, S., Köhler, J., Harpenslager, S.F. and Vermaat, J.E., 2023. Drivers of Perceived Nuisance Growth by Aquatic Plants. Environmental Management, 71(5), pp.1024-1036.

19. Franceschini, M.C., Hill, M., Fuentes‐Rodríguez, D., Gervazoni, P.B., Sabater, L.M. and Coetzee, J.A., 2023. Performance and field host range of the life stages of Cornops aquaticum, a biological control agent of water hyacinth. Entomologia Experimentalis et Applicata.

20. Reid, M.K., Hill, M.P. and Coetzee, J.A., 2023. Love at first bite? Pre-release surveys reveal a novel association between a native weevil and the invasive Nymphaea mexicana Zuccarini (Nymphaeaceae) in South Africa. African Entomology, 31, pp.1-8.

Last Modified: Tue, 19 Mar 2024 11:24:26 SAST