Junior Research Officer

Fiona Impson


Office: Based off campus, Vredenberg Farm, ARC-PPRI Stellenbosch





MSc (University of Cape Town); BSc (Hons) Entomology (Rhodes University); BSc Entomology and Zoology (Rhodes University)

Activities and Research Interests:

Fiona is an entomologist by training with an interest in ecology and plant insect interactions. She has worked in the field of biological control of weeds for the past 27 years and has been involved in projects against weeds such as Sesbania punicea, Prosopis species, Opuntia stricta, with most focus on invasive Australian Acacia species.

Fiona has travelled extensively to Australia to survey for and collect insects against several of the most invasive Acacia species in South Africa, and has been involved in all aspects of a biological control programme. Her research focuses on the post release evaluation of some of these insects, as well as the seed dynamics (seed rain and seed banks) of the plants. She is also involved in the management and training of two biological control implementation teams who have been employed through NRMPs, Expanded Public Works Programme.

Fiona joined the PCU in 2014 when the weed biocontrol research group became affiliated with the unit. She is based away from campus, at the ARC-PPRI’s research facility at Vredenberg Farm, Stellenbosch, where there has been a long history of close collaboration with biocontrol research staff.

Related Work Experience:

1989-1999 - Research Assistant to John Hoffmann, Zoology Department, University of Cape Town.

2000-2010 - Scientific officer, University of Cape Town (based at ARC PPRI, Stellenbosch).

2011-present - Junior Researcher, University of Cape Town (based at ARC PPRI, Stellenbosch).

Peer Reviewed Publications:

Compton, S.G. and Mclaren, F.A.C. 1989.  Respiratory adaptations in some male fig wasps. Proceedings of the Koninklijke Nederlands Akademie van Wetenschappen. Series C, 92(1): 57-71. March 20 1989.

Hoffmann, J.H., Impson, F.A.C. and Moran, V.C. 1993.  Biological control of mesquite weeds in South Africa using a seed feeding bruchid, Algarobius prosopis: Initial levels of interference by native parasitoids. Biological Control 3: 17-21.

Hoffmann, J.H., Impson, F.A.C. and Moran, V.C. 1993.  Competitive interactions between two bruchid species (Algarobius spp.) introduced into South Africa for the biological control of mesquite weeds (Prosopis spp.). Biological Control 3: 215-220.

Moran, V.C., Hoffmann, J.H., Impson, F.A.C. and Jenkins, J.F.G. 1994.  Herbivorous insect species in the tree canopy of a relict South African forest. Ecological Entomology 19: 147-154.

Hoffmann, J.H., Moran, V.C. and Impson, F.A.C. 1998.  Promising results from the first biological control programme against a solanaceous weed (Solanum elaeagnifolium). Agriculture, Ecosystems & Environment 70: 145-150.

Impson, F.A.C. and Hoffmann, J.H. 1998.  Competitive interactions between larvae of three bruchid species (Coleoptera) in mesquite seeds (Prosopis spp.) under laboratory conditions. African Entomology 6(2): 376-378.

Impson, F.A.C., Moran, V.C. and Hoffmann, J.H. 1999.  A review of the effectiveness of seed-feeding bruchid beetles in the biological control of mesquite, Prosopis species (Fabaceae), in South Africa. African Entomology Memoir No. 1: 81-88.

Dennill, G.B., Donnelly, D., Stewart, K. and Impson, F.A.C. 1999.  Insect agents used for the biological control of Australian Acacia species and Paraserianthes lophantha (Willd.) Nielsen (Fabaceae) in South Africa. African Entomology Memoir No. 1: 45-54.

Olckers, T., Hoffmann, J.H. Moran, V.C., Impson, F.A.C. and Hill, M. 1999.  The initiation of biological control programmes against Solanum elaeagnifolium Cavanilles and S. sisymbriifolium Lamarck (Solanaceae) in South Africa. African Entomology Memoir No. 1: 55-63.

Impson, F.A.C., Moran, V.C., Hoffmann, J.H., Donnelly, D. and Stewart, K. 1999.  Recent developments in the biological control of invasive acacias in South Africa: Melanterius ?servulus (Coleoptera: Curculionidae) against Acacia cyclops.  Proceedings of the X International Symposium on Biological Control of Weeds. N. Spencer (ed.). 4th-9th July 1999, Bozeman, Montana, USA.

Hoffmann, J.H., Impson, F.A.C., Moran, V.C. and Donnelly, D. 2002. Biological control of invasive golden wattle trees (Acacia pycnantha) by a gall wasp, Trichilogaster sp. (Hymenoptera: Pteromalidae), in South Africa. Biological Control 25: 64-73.

Hoffmann, J.H., Impson, F.A.C. and Volchansky, C.R. 2002. Biological control of cactus weeds: implications of hybridisation between control agent biotypes. Journal of Applied Ecology 39: 900-908.

Impson, F.A.C. and Moran, V.C. 2004. Thirty years of exploration for and selection of a succession of Melanterius weevil species for biological control of invasive Australian acacias in South Africa: should we have done anything differently? In: Proceedings of the XI International Symposium on Biological Control of Weeds (J.M. Cullen, D.T. Briese, D.J. Kriticos, W.M. Lonsdale, L. Morin, and J.K. Scott, eds), pp. 127-134. 27 April – 2 May 2003 CSIRO Entomology, Canberra, Australia.

Impson, F.A.C., Moran, V.C. and Hoffmann, J.H. 2004. Biological control of an alien tree, Acacia cyclops, in South Africa: impact and dispersal of a seed-feeding weevil, Melanterius servulus. Biological Control 29: 375-381.

Impson, F.A.C.; Moran V.C., Kleinjan, C.; Hoffmann, J.H. and Moore, J.A.  2007. Multiple-species introductions of biological control agents against weeds: look before you leap. In: Proceedings of the XII International Symposium on Biological Control of Weeds (eds. Julien, M.H., Sforza, R., Bon, M.C., Evans, H.C., Hatcher, P.E., Hinz, H.l. and Rector, B.G.), pp. 22-27 April 2007, La Grande Motte, Montpellier, France. CAB International Wallingford, UK.

Impson, F.A.C., Kleinjan, C.A., Hoffmann, J.H. and Post, J.A. 2008. Dasineura rubiformis (Diptera: Cecidomyiidae), a new biological control agent for Acacia mearnsii in South Africa. South African Journal of Science, 104: 247-248.

Post, J.A., Kleinjan, C.A., Hoffmann, J.H. and Impson, F.A.C. 2010. Biological control of Acacia cyclops in South Africa: The fundamental and realized host range of Dasineura dielsi (Diptera: Cecidomyiidae). Biological Control 53: 68-75.

Impson, F.A.C., Kleinjan, C.A., Hoffmann, J.H., Post, J.A. and Wood, A.R. 2011. Biological control of Australian Acacia species and Paraserianthes lophantha in South Africa. African Entomology, 19(2), 187-207.

Wilson, J.R.U., Gairifo, C., Gibson, M.R., Arianoutsou, M., Bakar, B.B., Baret, S., Celesti-Grapow, L., DiTomaso, J.M., Dufour-Dror, J.M., Kueffer, C., Kull, C.A., Hoffmann, J.H., Impson, F.A.C., Loope, L.L., Marchante, E., Marchante, H., Moore, J.L., Murphy, D.J., Tassin, J., Witt, A., Zenni, R.D. & Richardson, D.M. 2011. Risk assessment, eradication, and biological control: global efforts to limit Australian acacia invasions. Diversity and Distributions, 17(5), 1030-1046.

Richardson, D.M., Carruthers, J., Hui, C., Impson, F.A.C., Miller, J.T., Robertson, M.P., Rouget, M., Le Roux, J.J. & Wilson, J.R.U. 2011. Human-mediated introductions of Australian acacias – a global experiment in biogeography. Diversity and Distributions 17(5), 771-787.

Hirsch, H., Gallien, L., Impson, F.A.C., Kleinjan, C., Richardson, D.M., Le Roux, J.J. 2017. Unresolved native range taxonomy complicates inferences in invasion ecology: Acacia dealbata Link as an example. Biological Invasions 1-8. 10.1007/s10530-017-1381-9. 

Hirsch, H., Richardson, D.M., Impson, F.A.C., Kleinjan, C., Le Roux, J.J. 2018. Historical range contraction, and not taxonomy, explains the contemporary genetic structure of the Australian tree Acacia dealbata Link Tree Genetics & Genomes 14:49

Book Chapters:

Impson, F., Hoffmann, J.H. and Kleinjan, C. 2009. Australian Acacia species (Mimosaceae) in South Africa. In: Biological control of tropical weeds using arthropods (eds R. Muniappan, G.V. Reddy and A. Raman) pp. 38-62. Cambridge University Press.

Impson, F.A.C., Purcell, M.F. & Gordon, A.J. 2012. Biological control of Australian plants: a South African and U.S.A. perspective. In: Biological control of weeds in Australia 1960 to 2010 (M. Julien, R. McFadyen and J. Cullen Eds), pp. 1-17. CSIRO Publishing.

Wood, A.R. & Impson F.A.C. 2010. Threats to the flora. In: Oberholzer L. Lime stone fynbos of the Vermaklikheid area.

Edited Proceedings:

Impson FAC, Kleinjan CA and Hoffmann JHH (Eds.) 2014. Proceedings of the XIV International Symposium on the Biological Control of Weeds.  232pp.  Skukuza, Kruger National Park, South Africa. 2-7 March 2014.