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BIOLOGICAL CONTROL

The identification, screening, release and monitoring of biological agents for long term, cost-effective control of invading alien plants.

Effective biological control is an essential element in the sustainable management of invading alien plants, as in many cases it provides the only guaranteed long-term effective solution to problems of invasion. In South Africa, biological control research has been practised for more than 85 years, and more than 103 biological control agents have been released against 46 weed species. These control agents have already saved millions of Rands in control costs and reduced impacts.

The relatively large size of the budget (60%) should be interpreted in this light. Preliminary estimates indicate that the ongoing biological control programmes will reduce the financial commitment of the Working for Water programme for clearing costs by between 19.8% (R1.38 billion) and 41.4% (R2.89 billion) over the next 20 years. If the impacts of invading alien plants on water and other resources are taken into account, the potential returns on investment are even more substantial. This budget is therefore not only a research investment, it is an investment into the development and implementation of one of the essential pillars of alien plant control.

The current biological control research programme focuses on a number of priority weed species. The research programme is based in part on historic work on invasive weeds, but efforts have been made to phase out or rationalize work on less promising agents or weeds of lower priority, and to introduce new projects aimed at priority weeds, such as pines, Australian myrtles, and Australian Acacias. The review panel for biological control research has played a crucial role in guiding this rationalization process over the past year.

Extremely good progress with work on the potential control of Australian Acacia species was a feature of the work carried out during the 2000/2001 financial year. This genus has produced some of the most widespread and troublesome weeds in South Africa today, but there is a huge potential to reduce their seed output by means of seed-feeding and flower-galling insects. The attractive aspect of these solutions is that the trees themselves are not affected by the insects, and it will be possible to grow them and benefit from their products after the insects have been released. A number of insects have already been released. In addition, good progress was made with the identification and testing of several insects that could potentially reduce the seed output of pine trees, with similar advantages. In the case of both pines and acacias, there is ongoing consultation with the forest industry through steering committees.

Another notable feature was the creation of a project to initiate a biological control implementation programme. This project has progressed extremely well, and a large number of biocontrol agents have been reared in the field and released. In some cases, the initial impacts have been extremely promising. The project is unique, as the concept of active rearing and optimal release of biocontrol agents on a large scale has not been attempted against environmental weeds anywhere in the world before.

Biological control obviously relies on collaboration with countries where the weed species originates, and this often necessitates collaborative contracts in these countries. The recent declines in the value of the Rand against other major currencies will continue to put significant pressure on the research budget.

Biological Control Research Review Panel

Name	Organisation
Dr Brian van Wilgen (Chair)	Council for Scientific and Industrial Research (CSIR)
Mr Hennie Bosman	Department of Water Affairs and Forestry
Dr Dave Everard	South African Pulp and Paper Industries (SAPPI)
Dr Dumisani Magadlela	Working for Water
Prof. Cliff Moran	Retired (former Dean of Science at the University of Cape Town.
Dr Mike Morris	Private consultant in plant pathology
Dr Shadrack Moephuli	National Department of Agriculture
Mr Tyl Willems	Department of Water Affairs and Forestry
Dr Helmuth Zimmermann	Plant Protection Research Institute

Biological Control Research projects 2000/2001

Project	Budget (Rands)	Service Provider
Use of fungi for the bio-control of Prosopis species in South Africa	244 571	Plant Protection Research Institute (Stellenbosch)
The release, establishment and post-release evaluation studies of the leaf pathogen Mycovellosiella lantanae for Lantana camara.	169 373	Plant Protection Research Institute (Stellenbosch)
Screening, host specificity studies, release and post-evaluation studies of plant pathogens for the bio-control of Chromolaena odorata.	154 404	Plant Protection Research Institute (Stellenbosch)
Bio-control of Lantana camara using insect agents.	779 395	Plant Protection Research Institute (Pretoria)
Release and establishment of 2 new agents on Silky hakea, Hakea seriacea, and the evaluation of the dispersal ability of the existing agents.	299 504	Plant Protection Research Institute (Stellenbosch)
Host-specificity testing, establishment and evaluation of the insect agents imported to reduce the invasiveness of Bugweed, Solanum mauritianum.	547 730	Plant Protection Research Institute (Cedara)
Biological control of Chromolaena odorata: host-range testing, release and monitoring of selected insect agents.	419 118	Plant Protection Research Institute (Cedara)
Study of 2 new insect natural enemies for the bio-control of Water hyacinth, Eicchornia crassipes	430 331	Plant Protection Research Institute (Pretoria)
The introduction, release and evaluation of 3 new Melantarius species on Acacia dealbata, Acacia decurrens, A. saligna and the evaluation of Melanterius maculatus on Acacia mearnsii and Melanterius servulus on A. cyclops.	631 378	Plant Protection Research Institute (Stellenbosch)
The biological control of invasive Australian Acacia species. using seed-preventing Cecidomyiidae.	572 503	Plant Protection Research Institute (Stellenbosch)
The biological control of Pinus species in South Africa: Exploration of potential agents in Europe.	281 580	Instituto Nationale Recherche Agronomique (Orleans, France)
Biological control of golden wattle, Acacia pycnatha using a gall wasp Trichilogaster species.: Evaluation studies of the performance of the agent.	106 000	University of Cape Town
Host-range testing of the leaf mining moth Acrocercops hyphantica, a natural enemy of Mauritius thorn, Caesalpinia decapetala.	151 528	Plant Protection Research Institute (Pretoria)
Development of a bio-herbicide to control the invasive species Acacia Cyclops.	201 164	Plant Protection Research Institute (Stellenbosch)
Studies on the identity and host ranges of Bruchophagus spp., with a view to curbing seeding by Australian acacias.	337 544	Plant Protection Research Institute (Pretoria)
The redistribution and an evaluation of the efficacy of the leaf-mining moth, Parectopa thallasias and an unidentified gall-forming midge introduced to reduce the invasiveness of Australian myrtle, Leptospermum laevigatum.	225 800	Plant Protection Research Institute (Stellenbosch)
Implementation of biological control by the Working for Water programme.	306 130	Plant Protection Research Institute (Stellenbosch)
Study on the risks and benefits of using either biological control agents or herbicides in the fight against Water hyacinth.	65 000	Council for Scientific and Industrial Research (Pretoria)
Use of fungi for the bio-control of Prosopis species in South Africa	244 571	Plant Protection Research Institute (Stellenbosch)
The release, establishment and post-release evaluation studies of the leaf pathogen Mycovellosiella lantanae for Lantana camara.	169 373	Plant Protection Research Institute (Stellenbosch)
Screening, host specificity studies, release and post-evaluation studies of plant pathogens for the bio-control of Chromolaena odorata.	154 404	Plant Protection Research Institute (Stellenbosch)
Bio-control of Lantana camara using insect agents.	779 395	Plant Protection Research Institute (Pretoria)
Release and establishment of 2 new agents on Silky hakea, Hakea seriacea, and the evaluation of the dispersal ability of the existing agents.	299 504	Plant Protection Research Institute (Stellenbosch)
Host-specificity testing, establishment and evaluation of the insect agents imported to reduce the invasiveness of Bugweed, Solanum mauritianum.	547 730	Plant Protection Research Institute (Cedara)
Biological control of Chromolaena odorata: host-range testing, release and monitoring of selected insect agents.	419 118	Plant Protection Research Institute (Cedara)
Study of 2 new insect natural enemies for the bio-control of Water hyacinth, Eicchornia crassipes	430 331	Plant Protection Research Institute (Pretoria)
The introduction, release and evaluation of 3 new Melantarius species on Acacia dealbata, Acacia decurrens, A. saligna and the evaluation of Melanterius maculatus on Acacia mearnsii and Melanterius servulus on A. cyclops.	631 378	Plant Protection Research Institute (Stellenbosch)
The biological control of invasive Australian Acacia species. using seed-preventing Cecidomyiidae.	572 503	Plant Protection Research Institute (Stellenbosch)
The biological control of Pinus species in South Africa: Exploration of potential agents in Europe.	281 580	Instituto Nationale Recherche Agronomique (Orleans, France)
Biological control of golden wattle, Acacia pycnatha using a gall wasp Trichilogaster species.: Evaluation studies of the performance of the agent.	106 000	University of Cape Town
Host-range testing of the leaf mining moth Acrocercops hyphantica, a natural enemy of Mauritius thorn, Caesalpinia decapetala.	151 528	Plant Protection Research Institute (Pretoria)
Development of a bio-herbicide to control the invasive species Acacia Cyclops.	201 164	Plant Protection Research Institute (Stellenbosch)
Studies on the identity and host ranges of Bruchophagus spp., with a view to curbing seeding by Australian acacias.	337 544	Plant Protection Research Institute (Pretoria)
The redistribution and an evaluation of the efficacy of the leaf-mining moth, Parectopa thallasias and an unidentified gall-forming midge introduced to reduce the invasiveness of Australian myrtle, Leptospermum laevigatum.	225 800	Plant Protection Research Institute (Stellenbosch)
Implementation of biological control by the Working for Water programme.	306 130	Plant Protection Research Institute (Stellenbosch)
Study on the risks and benefits of using either biological control agents or herbicides in the fight against Water hyacinth.	65 000	Council for Scientific and Industrial Research (Pretoria)
TOTAL	5 923 053

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