Biological control as a management tool for suppression of terrestrial invasive alien plants in South Africa

Biological control as a management tool for suppression of terrestrial invasive alien plants in South Africa
Costas Zachariades1,2, Iain D. Paterson3, Lorraine W. Strathie1, Brian W. van Wilgen4
1ARC-Plant Protection Research, Private Bag X6006, Hilton 3245, South Africa
2School of Life Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville 3209, South Africa
3Department of Zoology and Entomology, Rhodes University, PO Box 94, Grahamstown 6140, South Africa
4Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa

Biological control of invasive alien plants has the ability to contribute significantly to sustained, cost-effective management of natural resources of South Africa. The status of and prospects for the biological control of terrestrial plants in South Africa is therefore integral to the National Status Report. Considerable advances in the processing of new agents for release and successes in field on a number of invasive alien plants have been achieved in South Africa in recent years. The highlights and constraints in the biological control of major terrestrial IAPs within South Africa, as well as the prospects for success, are discussed. Major IAPs include those species that are currently considered the most damaging in the country as well as those of historical importance that would be major problems if biological control had not been implemented. The role of biological control in the management of both established and emergent terrestrial IAPs (in some cases grouped according to taxonomy or growth habit) is also discussed. Candidate terrestrial IAP targets for management using biological control are prioritised. An opinion is provided on where biological control might facilitate a change in the NEMBA categorisation for some terrestrial species. The implications of implementing recommendations contained in the National Strategy on Biological Invasions in South Africa that explicitly call for improvements to the capacity for research and implementation of weed biological control, are explored. The need for broader understanding and adoption of the practice of biological control of IAPs is emphasised as essential to the realisation of the full benefits of investment of resources.