Biological Control (Biocontrol)
Biological control involves introducing natural enemies of a weed, usually an insect or disease, to help to manage it. Biocontrol is an attempt to restore balance so that the weed does not have such an advantage over native plants. It is not an attempt to eradicate the weed.
A biocontrol program involves searching plants in their native country for any insects or diseases that appear to be damaging the plant. Any promising agents are then tested for several years to ensure that they feed only on the target weed. Agents can only be released in Australia if they have gone through a very strict screening process.
Biological control options for invasive weeds are expanding at a rapid rate. However, scientists caution that biocontrol will never be a 'cure-all' or replacement for existing control methods.
Scientists stress that the successful long-term management of weeds depends on a combination of biological, chemical and physical methods. Ideally these methods should be applied in conjunction with appropriate quarantine procedures and improved land management techniques.
For example, biological control of salvinia has been very successful, and only small amounts of herbicide are now required to manage the weed.
The Northern Territory biological control program is a cooperative project between the Department of Natural Resources, Environment and the Arts and CSIRO Entomology.
Biological control in the NT has mainly focused on the following species:
- Mimosa (Mimosa pigra)
- Bellyache bush (Jatropha gossypiifolia)
- Spinyhead Sida (Sida acuta)
- Salvinia (Salvinia molesta)
- Parkinsonia (Parkinsonia aculeata)
- Noogoora burr (Xanthium occidentale)
- Hyptis (Hyptis suaveolens)
- Mexican poppy (Argemone orchroleuca)
Agonosoma adult on bellyache bush fruit
A table outlining The research and development of biological control agents in the NT is available for download.
