WWF's Conservation Innovation Awards

Gathering votes
Gathering votes


Idea in a nutshell: Using target specific bio-control agents to reduce the negative impact of weeds on NZ biodiversity.

Aim: To implement a plant pest control programme to target some of the major plant pests in New Zealand that was cheaper, more efficient, healthier, more environmentally friendly and more target specific than the traditional use of herbicide sprays.

Environmental opportunities: This programme has found a better way to deal with some of the most aggressive pest plants in New Zealand. Biocontrol is more cost effective than spraying, it is safer for the environment and handlers, it is a long term solution and is very target specific. This control method offers the opportunity to improve native biodiversity throughout New Zealand by getting effective control over a number of the most significant weeds affecting our natural habitats.

What conservation problem are you trying to solve?

Conservation problem: Trying to find a better way to deal with major plant pests affecting biodiversity in New Zealand that was cheaper, more efficient, healthier, more environmentally friendly and more target specific than the traditional use of herbicide sprays. Pest plants (weeds) are a major threat to natural areas and native biodiversity In NZ.  

Weed control problem: Weeds tend to be fast growing, hardy, spread quickly and are hard to eradicate.  The initial cost of a biocontrol release is substantial, but a successful release is a gift that keeps on giving, so when compared to the use of chemical control, which is temporary and tends to need to be repeated year after year, as well as often leading to unwanted side effects, the business case becomes very robust.

H&S problem: Additionally, as we become aware of the Health & Safety risks of using toxic chemicals, both for the environment and humans, the option of using non-toxic insects becomes more attractive.

How are you going to solve this conservation problem?

Problem: Weeds are taking over New Zealand.

Idea: Using target specific bio-control agents to reduce the negative impact of weeds on NZ biodiversity.

Biggest challenges: Convincing decision makers to allow novel biocontrol organisms to be used as an alternative to the methods people are accustomed to (chemical spraying) was the biggest challenge. 

I am working with partners in the Waikato Regional Council and Landcare Research to implement a pest plant biological control programme. Biological control agents approved by the Environmental Protection Authority were selected for three of the most serious plant pests; wandering dew, woolly nightshade  and Chinese privet. Initial releases was undertaken in a high value native bush reserve where chemical control would have caused unwanted collateral damage to the habitat.

We hope to have a comprehensive control programme using biological control methods in the next established in 5-10 years.

What makes your idea new and unique?

What makes your idea new and unique?

The beauty of biological control agents is that they are designed by nature and fit in to very specific ecological niches. Being living organisms they will increase and decrease their populations in response to the amount of host organism in the environment. So a small release in a large weed infestation can multiply to levels to effectively reduce the weed infestation, and then reduce correspondingly in population numbers as the weed is reduced. Also, being living organisms they will actively seek out hosts and therefore a release at any point in a catchment is likely to spread throughout the catchment to deal will all weeds in the area. This programme has found a better way to deal with some of the most aggressive pest plants in New Zealand. Biocontrol is more cost effective than spraying, it is safer for the environment and handlers, it is a long term solution and is very target specific. 

Who will use your idea, and how will they benefit?

Anyone can use the idea! The benefits to the community are already becoming evident, with landowners and project managers asking to become involved and looking for biocontrol agents for their sites. As populations become established, the aim is to be able to have enough biocontrol agents to be able to establish releases everywhere there is a need. Biological control of Tradescantia is cheaper, longer lasting and causes no damage to native species.

Chemical control is more expensive, needs to be repeated every year and has the potential to damage native species. Certain countries have already banned certain chemical sprays due to their health risks to humans.

Biological control is much cheaper and less damaging than chemical control over the life of the programme. It takes longer to see a result, but lasts forever. 

What tasks or activities do you need investment for? How would you spend a $25,000 grant?

Tasks and activities: The strategy for the programme is twofold, with the first plan to continue monitoring and establishing release sites throughout the District, and the second plan is to work with Landcare Research to utilize other biological control agents for release in the Waikato. We are looking at a butterfly to control Japanese honeysuckle which is a major weed pest affecting biodiversity in the region.

Grant usage: A $25,000 grant would be used improve the biocontrol project, for example by purchasing more biocontrol agents to increase the speed of spread in the environment and thereby achieve greater success sooner. A considerable amount of education and interest has been achieved through this project, especially with regard to the ease of use of the biological control agent and its many positive attributes. Everyone we speak to wants some of the bugs!

Are you a New Zealand citizen or resident?


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List five other ideas posted in the challenge that excite you. Why?

There are more than 5 other ideas that excite. Here the top ones and why:

Swimming with e-coli - a hot topic and this idea will provide live information on an important indicator of water quality.

Subscribe to a marine reserve - using social media type apps to raise awareness and profile marine reserves is a great idea.

The Baleen filter - micro plastics are a major negative impact in the environment. This idea deals with smaller fragments.

Restoration drone for polluted waterways - plastics again; this time dealing with the front end of plastics ending up in the environment.

One self re-setting trap that kills both possums and rats - an improvement on existing designs.


X-specs - aims to bring diffuse environmental information together in an organised way.

How could you improve your idea?

Plant pest control is only one element in a native biodiversity improvement programme. The best ecological enhancement plans incorporate all facets of natural resource management. To improve the idea, one has to realise that the use of autonomous weed eaters is only part of a wider programme that aims to improve native biodiversity. Other facets of this programme include mammalian pest control, planting of native species, stock proofing, water quality improvement initiatives and working with others to add value and develop positive outcome synergies. Putting this project forward under the WWF Conservation Innovation Awards is only one of a number of initiatives to improve on the habitat restoration programme. An approach is being made to the Predator Free 2050 programme to increase effort in that space, as well as other collaborative and funding applications for ecological enhancement. Some of the other ideas being generated here may provide opportunity for collaboration. Together we can make the difference and turn the tide on biodiversity loss in NZ.

edited on Oct 17, 2017 by EcologistBW

Nigel Binks Oct 5, 2017

How target-specific will the biocontrols be and how do you propose to validate their specificity? Biocontrol wasps (Microtonus spp) were introduced by AgResearch in the 1990's to combat pasture pests, Clover Root Weevil and the Argentine Stem Weevil populations. However long-terms data and publications have determined that, as with many biocontrol programs, prey specificity which was determined in controlled conditions did not account for the adaptability of the biocontrol organisms. Often this translates to non-target taxa becoming prey and pressured by these introduced species. Unless successful at eradication short-term, there is a concern that over time biocontrol organisms just become background mediators.


EcologistBW Oct 6, 2017

Hi everyone,
With regards to the question around target specificity that SpiderGuyNige posted:
Rigorous research into weed biocontrol host range testing internationally has shown that testing undertaken in accordance with best practice protocols (which Landcare Research follow) is a highly reliable predictor of agent behaviour in the field. Only agents with a suitably narrow host-range are selected and put forward to the EPA for permission to release. Weed biocontrol has an excellent safety record in New Zealand. For example, Japanese honeysuckle is only very distantly related to native New Zealand plants, further reducing the risk of non-target attack, which is considered to be infinitesimally low. SpiderGuyNige is correct that introduced Microctonus species do attack native beetles in New Zealand, with M. aethiopoides being the worst offender. This species was introduced into New Zealand in 1981 following minimal host specificity testing. Retrospective specificity testing indicated that non-target attack would have been predictable, had it been done, and so it is not a case of changing host post release. The release of M. aethiopoides in New Zealand would not be sanctioned under today’s regulatory system.
Oh, and SpiderGuyNige - please ask your spiders not to eat our biocontrol agents! Have a nice weekend.


Fiona Edwards Oct 8, 2017

Kia ora, I agree that biocontrol is a great tool for weed control. Can you please clarify what is game changing about this project, as biocontrol is already in use for some weed species? How does this project differ from other biocontrol projects?


EcologistBW Oct 9, 2017

Kia ora Fiona,
Biocontrol is a cutting edge game changer – we are constantly looking for new biocontrol agents that are suitable for use in NZ. The difference in this project is that it is looking for the newest and most suitable innovations in biocontrol, looking for pest plant reduction without collateral damage, working towards a comprehensive, large scale weed control programme, working with partners and trying to add value to existing ecological enhancement activities, encouraging others to give it a try. The game changer is in changing deep rooted mindset about how to deal with weeds, i.e. ditch the spray and let nature have a go! Putting this idea forward in the WWF Conservation Innovation Awards is a high profile way to promote the use and benefits of biocontrol (as well as hopefully getting some more resource to grow the programme). Thanks for your support!


Becky Wilson Oct 9, 2017

The idea has been progressed to the next milestone


Jonathan Boow Oct 15, 2017

Hi there, I'm still a little unclear what you're proposing that's 'innovative' here. It looks like you're asking for funding to release more individuals of biocontrol agents that are already approved for release in NZ by the EPA. Further releases of these agents is obviously a good thing and you've rightly identified funding is a current limitation. However, I don't see purchasing of more agents as necessarily innovative (getting community groups or landowners involved in rearing agents for wider release would be), nor telling people that it's an 'either/or' between biocontrol agents and herbicide use - but that's a longer discussion that we probably can't resolve via this comments thread(!)


EcologistBW Oct 16, 2017

Hi Jonathan,
Thanks for your suggestion about adding innovation by getting landowners involved in rearing biocontrol agents. Actually, this is an existing part of the idea and already in motion. For example, we are finding that this works really well with woolly nightshade lacewings – they are easy to spot, breed well and easy to catch for translocation. As for herbicides, the discussion is around the benefits of biocontrol versus the negative effects of chemicals, not an either/or stance. Another discussion point is that every unit of chemical costs money, whereas once you have undertaken the initial investment, every new unit of biocontrol is essentially free. That kind of innovation is worthy of support and one of the reasons we put this idea forward. Regarding money, I guess like all the ideas being put forward, a cash injection would help; but even just being part of the conservation conversation and getting people interested is healthy and positive. Thank you for supporting biocontrol agents – I think they are a good thing too!