Biological control
https://archive.gw.govt.nz/biological-control
Biological control
Most pest plants have arrived in New Zealand without their natural enemies that may have kept them in check in their own countries.
Biological control or 'biocontrol' involves bringing some of those natural enemies to New Zealand to help control the plant. Biocontrol organisms are usually insects but can also be animals, rusts or viruses.
Biocontrol agents provide assistance in the control of pest plants that are widespread. It is a very long term approach to pest control.
Before any new organism is brought into New Zealand, strict testing procedures are followed, often over a period of years, to ensure that the new organism poses no risk to valued species.
The biocontrol agent has to be proven to attack only the pest plant and no other plant species.
Buddleia weevil larvae
Manaaki Whenua Landcare Research undertakes the research and trialling of such biocontrol organisms which are then released by either regional council or Department of Conservation (DOC) staff (after approval from the Environmental Protection Authority (EPA)). Release sites are studied further to ascertain the success of the release and to guide future releases.
Greater Wellington contributes towards the biological control collective which includes the majority of regional councils, DOC and several district councils. Greater Wellington biosecurity officers currently release biocontrol agents in the Wellington region. When agent populations are high enough, they may distribute them on to new sites.
Biocontrol agents released in the Wellington Region
Pest plant and biocontrol agents |
First released |
Total number of known sites |
Overall agent status |
|
Boneseed agents |
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Boneseed leaf roller |
2007 |
8 |
No evidence of population establishing |
|
Broom agents |
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|
Broom gall mite |
2009 |
800+ |
Agent established |
|
Broom leaf beetle |
2009 |
3 |
We are unsure if the agent has established a population yet |
|
Broom psyllid |
1995 |
1000+ |
Now widespread in our region |
|
Broom seed beetle |
1994 |
600+ |
Now widespread in our region |
|
Broom shoot moth |
2008 |
3 |
We are unsure if agent has established a population yet |
|
Buddleia agents |
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|
Buddleia leaf weevil |
2007 |
100+ |
Agent established and becoming widespread |
|
Darwin’s barberry agents |
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|
Darwin’s barberry seed weevil |
2016 |
4 |
We are unsure if the agent has established a population yet |
|
Gorse agents |
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|
Gorse colonial hard shoot moth |
2002 |
5 |
Agent failed to establish any populations in our region |
|
Gorse pod moth |
1997 |
abundant |
Now widespread in our region |
|
Gorse soft shoot moth |
2007 |
12 |
We are unsure if the agent has established a population yet |
|
Gorse spider mite |
1989 |
abundant |
Now widespread in our region |
|
Gorse thrips |
1990 |
abundant |
Now widespread in our region |
|
Japanese Honeysuckle |
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|
Japanese Honshu white admiral butterfly |
2017 |
7 |
We are unsure if the agent has established a population yet |
|
Mistflower agents |
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|
Mistflower gall fly |
2001 |
2 |
Agent established |
|
Mistflower fungus |
2009 |
1 |
Agent established |
|
Old man’s beard agents |
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|
Old man’s beard leaf fungus |
1997 |
3 |
Agent failed to establish any populations in our region |
|
Old man’s beard leaf miner |
1995 |
abundant |
Now widespread in our region |
|
Old man’s beard sawfly |
2002 |
2 |
Agent failed to establish any populations in our region |
|
Privet agents |
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|
Privet lace bug |
2015 |
- |
Agent failed to establish any populations in our region |
|
Ragwort agents |
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|
Cinnabar moth |
2006 |
abundant |
Now widespread in our region |
|
Ragwort plume moth |
2012 |
6 |
Agent established |
|
Ragwort flea beetle |
1988 |
abundant |
Now widespread in our region |
|
Thistle agents |
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|
Californian thistle flea beetle |
1994 |
2 |
Agent failed to establish any populations in our region |
|
Californian thistle gall fly |
2006 |
1 |
Agent failed to establish any populations in our region |
|
Californian thistle leaf beetle |
1993 |
2 |
Agent failed to establish any populations in our region |
|
Californian thistle stem miner |
2010 |
2 |
We are unsure if the agent has established a population yet |
|
Green thistle beetle |
2008 |
229 |
Established and becoming widespread |
|
Nodding thistle receptacle weevil |
1972 |
9 |
Now widespread in our region |
|
Nodding thistle crown weevil |
1990 |
4 |
Agent established |
|
Nodding thistle gall fly |
2005 |
12 |
Agent established |
|
Scotch thistle gall fly |
2005 |
79 |
Agent established |
|
Tradescantia agents |
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|
Tradescantia leaf beetle |
2011 |
9 |
Agent established |
|
Tradescantia stem beetle |
2012 |
10 |
We are unsure if the agent has established a population yet |
|
Tradescantia tip beetle |
2013 |
7 |
We are unsure if the agent has established a population yet |
|
Tradescantia yellow leaf spot fungus |
2018 |
5 |
We are unsure if the agent has established a population yet |
|
TOTALS: |
|
3000+ |
|
Biocontrol agents are currently being researched for a wide range of common pest plants including banana passionfruit, wild ginger, Japanese honeysuckle and Darwin's barberry.
For more information contact us on 0800 496 734, email pest.plants@gw.govt.nz or visit the Landcare Research website.
