In this section:
Community implementation of biological control of weeds across south-eastern Australia
Principal Investigator: Ken Henry
Research Officers: Susan Ivory, Joanne Kent
Target weeds: Boneseed Chrysanthemoides monilifera ssp monilifera, English broom Cytisus scoparius, Cape broom Genista monspessulana, blackberry Rubus fruticosus aggregate and gorse Ulex europaeus.
Target agents: Blackberry leaf rust Phragmidium violaceum, gorse thrips Seriocothrips staphylinus, boneseed leaf buckle mite Aceria sp., Cape broom psyllid Arytinnis hakani, English broom gall mite Aceria genistae.
PROJECT SUMMARY
The primary aim of the project is to increase the involvement of community groups in the distribution of biological control agents across New South Wales, Victoria, Tasmania and South Australia.
BIOLOGICAL CONTROL
Biological control uses the natural enemies of a weed to restrict its spread and reduce its population to a level that has minimal impact on the environment and the economy. In most cases this involves a suite of insects and pathogens working on different parts of the plant, from root to flower-head and seed. Ideally, agents will have overlapping climatic and environmental preferences to enable a degree of biological control across the full geographical range of the weed.
Biological control becomes part of the integrated weed management program, used in conjunction with more traditional control methods, as well as cultural changes, to control the weed across the complete landscape.
Biological control offers long term control for low priority management areas, for difficult to access locations and in places that are too sensitive for other forms of control.
COMMUNITY PARTICIPATION
Community participation ensures the long term knowledge and management of release sites. Community participation in biological control programs for weeds, such as salvation Jane and bridal creeper, has greatly strengthened the distribution effort and enabled the early establishment and spread of biological control agents across most of the relevant areas of South Australia.
In addition to involving the community in releases of biological control this project is aiming to encourage community groups to cultivate their own boneseed leaf buckle mite (BLBM) Aceria species on potted boneseed plants. Boneseed Biocontrol Community Nursery Factsheet (.PDF). The benefits of establishing this type of community nursery include:
- A convenient and continuous supply of BLBM
- A greater supply of mites and greater quantity of releases
- Reduced risk of mite loss caused by accidental destruction of field sites through grazing, spraying, weeding or burning
TARGET WEEDS
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Figure 1. Blackberry Rubus fruticosus. |
Blackberry (Fig. 1), boneseed (Fig. 2) and gorse (Fig. 3) are all Weeds of National Significance (WoNS), each with their own national management strategy, national taskforce and national coordinator. Cape broom (Fig. 4) and English broom (Fig. 5) are both important and highly recognised weeds across south-eastern Australia. |
Figure 2. Boneseed Chrysanthemoides monilifera ssp. Monilifera. |
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Figure 3. Gorse Ulex europaeus. |
Figure 4. Cape broom Genista monspessulana. |
Figure 5. English broom Cytisus scoparius. |
SELECTED BIOLOGICAL CONTROL AGENTS
The agents selected for this project are relatively new and, in most cases, are slow to disperse naturally. Information on individual agents can be found at the links list below.
Cape broom
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Figure 6. Arytinnis hakani adult. |
The Cape broom psyllid, Arytinnis hakani Loginova, 1972 (Hemiptera: Psyllidae) (Fig. 6), is a sap-sucking insect. Up to five generations can occur per year, with four generations developing in spring and possibly one in autumn. Nymph and adult A. hakani insert their mouthparts into Cape broom plants, injecting saliva and then sucking plant cells and sap. Damage to heavily infested plants includes shoot-blackening, reduced growth and flowering. |
Blackberry
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The fungus, Phragmidium violaceum (Schultz) G. Winter (1880) (Uredinales: Phragmidiacae) (Fig. 7 and 8), appears on the upper side of the leaves as purple-brown blotches and causes defoliation of the blackberry plant, attacking leaves, unripe fruit, flower buds and green parts of growing stems. Heavily infected leaves turn brown, shrivel and fall from the plant. |
Figure 7. Blackberry leaf rust Phragmidium violaceum: over-wintering spores. |
Figure 8. Phragmidium violaceum: golden summer spores.
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Boneseed
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Figure 9. Boneseed leaf buckle mite Aceria sp. Photo courtesy of Charmie Craemer, Plant Protection Research Institute, Pretoria, and Alan Hall, University of Pretoria, South Africa. |
The boneseed leaf buckle mite Aceria (Keifer, 1944) sp. (Acari: Eriophyidae) (Fig. 9) life cycle consists of egg, larva, nymph and adult, taking possibly up to 20 days. The adults are 0.15mm long and 0.05mm wide and have piercing and sucking mouthparts, extracting cell contents. Damage is caused by the formation of specialised galls (erinea, pl. and erinaeum, sing.), consisting of abnormal hair growth associated with distorted area of the leaf. A colony of mites lives in each erineum. The distortion of the leaves results in a reduction of photosynthetic tissue and hence, reduction in plant vigour.
More Information VicDPI |
English broom
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Figure 10. Aceria genistae adult. Source: http://new.dpi.vic.gov.au Aceria genistae (Nalepa) Castagnoli (Acari: Eriophyidae) gall mite (Fig. 10) feeding induces abnormal plant tissue growth, into a rosette-shaped gall. Mites cause flower deformation, preventing plant reproduction. |
Figure 11. Arytainilla spartiophylla adult. Arytainilla spartiophylla (Förster) (Hemiptera: Psyllidae) psyllid (Fig. 11) adults cause sucking damage, preventing flowering and also causes damage to leaves. |
Figure 12. Bruchidius villosus adult. Bruchidius villosus Fabricius (Coleoptera: Bruchidae) seed beetle |
Figure 13. Leucoptera spartifoliella adult. Leucoptera spartifoliella (Hübner) (Lepidoptera: Lyonetiidae) twig-mining moth (Fig. 13) larvae mine up and down stems of previous season’s growth in plant. Stunted plant growth and stem death results from heavy moth larvae infestation. |
More Information VicDPI
Gorse
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Source: http://www.dpi.vic.gov.au Seriocothrips staphylinus Haliday (Thysanoptera: Thripidae) (Fig. 14) larvae and adults pierce the plant epidermis, suck out contents of cells underneath, causing foliar damage to the plant. |
Figure 15. Tetranychus lintearius adult. Tetranychus lintearius Dufour (Acari: Tetranychidae), the gorse spider mite (Fig. 15), extracts plant cell contents, causing the foliage to appear bleached or brown. Extensive feeding kills shoots, reduces plant growth and stops flower production and development. |
Figure 16. Exapion ulicis adult. Exapion ulicis Förster (Coleoptera: Brentidae), the gorse seed weevil (Fig. 16) larvae feed on the developing seed and the adults feed on the soft tissue of stem and spines, creating holes in the plant. |
More Information VicDPI and Weeds Australia
Collaborators
Department of Primary Industries Victoria
Department of Primary Industries New South Wales
Tasmanian Institute of Agricultural Research (TIAR)
South Australian Department for Environment and Heritage – SA State Herbarium
Adelaide Mount Lofty Ranges Natural Resources Management Board
South Australian Murray Darling Basin Natural Resources Management Board
South East Natural Resources Management Board
Funding Sources
Caring for our Country – Australian Government, Vic DPI, TIAR, NSW DPI
