Rhodes>Botany>Staff>Julie Coetzee

Julie Coetzee

PhD. (Wits)Julie Coetzee

Associate Professor

Julie’s primary interest is plant-insect interactions, in the applied context of biological control of invasive species. She works on both floating and submerged aquatic weeds, and currently focuses on regime shift and resilience aspects of the invasion ecology of this suite of plants. Other interests include insect physiology, species distribution modelling, aquatic plant ecology and biostatistics. Further information about her research can be found here.

Julie teaches undergraduate courses in cell biology, as well as invasion biology and systems ecology.

Post-graduate supervision

Current students


Emily Strange (Rhodes, 2014-current). A study into the mechanisms driving submerged aquatic invasions in South Africa.

Samuel Motitsoe (Rhodes, 2016-curent). Does biological control drive regime shifts and trophic cascades in freshwater ecosystems?        


Zolile Maseko (Rhodes, 2014-current). Nutrient dynamics of Salvinia molesta in shade and open sites: is plant quality affecting the success of biological control by Cyrtobagous salviniae.

Nomvume Petela (Rhodes, 2014-current). Interactions between Megamelus scutellaris and Eccritotarsus catarinensis, control agents of water hyacinth.

Sisanda Mvandaba (Rhodes, 2014-current). The thermal physiology of Stenopelmus rufinasus Gyllenhal (Coleoptera: Curculionidae and Neohydronomus affinis Hustache (Coleoptera: Curculionidae), biological control agents of floating aquatic weed in South Africa.

Rosali Smith (Rhodes, 2015-current). Developing a  biological control programme for the submerged aquatic weed, Egeria densa, in South Africa.

Tamzin Griffith (Rhodes, 2016-current). Phenotypic plasticity or adaptation in the mirid, Eccritotarsus catarinensis.

Prinavin Naidu (Rhodes, 2016-current). Invasion ecology of Nymphaea mexicana in South Africa.


Past students


Grant Martin (2013). Potential for the introduction, establishment and spread of submerged invasive aquatic plants in South Africa.

Philip Weyl (2015). Investigating the origins of a suspected weed, Myriophyllum spicatum Linnaeus (Haloragaceae), in South Africa

Bronwen May (2015). To compensate or defend: investigations into insect-induced aquatic plant defences.

Candice Owen (2016). Life history of the maritime Platygastrid Echthrodesis lamorali Masner (Hymenoptera: Scelionidae).




Luke Schutz (Wits, 2007). A pre-release survey of the invasive water weed Hydrilla verticillata, and its associated insects on Pongolapoort Dam, KwaZulu-Natal, South Africa.

Taryn Morris (Wits, 2008). The impacts of invasive alien plant clearing on riparian vegetation recovery along the SabieRiver in the KrugerNational Park.

Kyle Harris (UP, 2009). Assessing and monitoring local scale impacts of Opuntia stricta on arthropod assemblages in the Kruger National Park, South Africa.

Colin Fordham (Rhodes, 2011). Mapping the Myriophyllum spicatum L. infestation in the VaalRiver, and recommendations for control.

Louise Stafford (Rhodes, 2014). The ecological and socio-economic impacts of aquatic weed biological control in the CapeMetro.

Some recent publications include:

Coetzee JA & Hill MP. 2012. The role of eutrophication in the biological control of water hyacinth, Eichhornia crassipes, in South Africa. BioControl 57:247–261.

Coetzee JA. 2012. Meteorological weather station data can be used in climate matching studies of biological control agents. Biocontrol Science and Technology 22: 419-427

Martin GD, Coetzee JA & Baars J-R. 2013. Hydrellia lagarosiphon Deeming (Diptera: Ephydridae), a potential biological control agent for the submerged aquatic weed, Lagarosiphon major (Ridl.) Moss ex Wager (Hydrocharitaceae). African Entomology 21: 151-160.

May B & Coetzee JA. 2013. Comparisons of the thermal physiology of water hyacinth biological control agents: predicting establishment and distribution pre- and post-release. Entomologia Experimentalis et Applicata. 147: 241-250.

Martin GD & Coetzee JA. 2014. Competition between two aquatic macrophytes, Lagarosiphon major (Ridley) Moss (Hydrocharitaceae) and Myriophyllum spicatum Linnaeus (Haloragaceae) as influenced by substrate sediment and nutrients. Aquatic Botany 114: 1-11.

Coetzee JA, Jones RW & Hill MP. 2014. Water hyacinth, Eichhornia crassipes Pontederiaceae), reduces benthic macroinvertebrate diversity in a protected subtropical lake in South Africa. Biodiversity and Conservation, 23:1319–1330.

Owen C A, Coetzee JA & van Noort S. 2015. Distributional range of the South African maritime spider-egg parasitoid wasp, Echthrodesis lamorali (Hymenoptera: Platygastridae: Scelioninae). African Invertebrates 55: 323-332.

Weyl PSR & Coetzee JA. 2015. Morphological variations in the southern African populations of Myriophyllum spicatum: phenotypic plasticity or local adaptation? South African Journal of Botany, in press.

Weyl PSR, Thum RA, Moody ML, Newman RM & Coetzee JA. 2016. Was Myriophyllum spicatum L. (Haloragaceae) recently introduced to South Africa from Eurasia? Aquatic Botany, 128: 7-12.

Madeira PT, Hill MP, Dray Jr FA, Coetzee JA, Paterson I, & Tipping PT. 2016. Molecular identification of Azolla invasions in Africa: the Azolla specialist, Stenopelmus rufinasus proves to be an excellent taxonomist. South African Journal of Botany, in press.

Last Modified: Tue, 27 Jun 2017 11:59:53 SAST