Editorial: Developing better tools for managing pests
Possum with young
In November 2016, the International Union for Conservation of Nature (IUCN) launched the ‘Honolulu Challenge on Invasive Species’. Coming out of the September 2016 IUCN World Congress, the Challenge recognises the losing battle being fought against invasive species globally, and calls for an international increase in efforts and initiatives to both stop new incursions (such as myrtle rust) and better manage legacy pests (such as weeds and invasive predators). New Zealand is helping spearhead this international challenge, with our Predator Free 2050 goals to eradicate rats, possums and stoats from the country being a lead initiative. Landcare Research and our collaborators are helping spearhead the research needed to achieve both these local pest management goals and the wider global vision.
And for just rats, possums and stoats, the research needs are broad. I’ve been pulling material together for an overview talk on ‘Predator Free 2050’ that I gave at the 17th Australasian Vertebrate Pest Conference in Canberra last April. This exercise brought home three key realisations. First, local pest managers and researchers have made amazing advances in their ability to manage invasive predators in the past 60+ years. They have gone from eradicating rats off islands of a few hectares in the Hauraki Gulf in the 1960s, to eradicating them off Campbell Island (112,700 ha) in the 2000s. Second, notwithstanding this progress, Predator Free 2050 is an audacious goal. It’s audacious in a good sense – the global community find what is being achieved is inspirational, and is once again looking to New Zealand to lead the way. But pest managers now need to scale up their plans to the eradication of predators from the 27 million ha of New Zealand.
And this is where the third realisation comes in. Multiple research streams on traps, toxins, making old approaches better, identifying new approaches, detection devices, and understanding the ecology and behaviour of target pest species have enabled an increase in the areas eradicated from the 20th to the 21st century not in a linear fashion but in a logarithmic fashion. This means that the capability to get the job done has been accelerating, and it’s been combinations of tools and approaches, each with their own strengths and weaknesses, that has allowed this. So, this is the challenge now. This broad range of research must be kept going to support the accelerating pace of pest management.
In this issue of Kararehe Kino, some of the latest advances are showcased. Many of Landcare Research staff are working with the New Zealand’s Biological Heritage National Science Challenge. Patrick Garvey and colleagues discuss a new type of stoat lure being developed with the Challenge, based on higher-order predator rather than food or mating odours, which could enhance the detection and trapping of these devastating pests of native fauna. And the Biological Heritage Challenge is not just about invasive vertebrates. Bob Brown and Ronny Groenteman present work on using infectious mites and parasitoids to control invasive wasps, predators in their own right (of native invertebrates and honey bees).
Helping the Biological Heritage Challenge with its mission to “reverse the decline of New Zealand’s biological heritage” is a wide range of other research projects. Advances are still being made in the optimisation of conventional approaches to pest management. Graham Nugent and colleagues show how aerial 1080 can be used not only for the eradication of bovine tuberculosis, but also how with modern application methodology it comes very close to also eradicating possums and rats. Further advancement could very well take this up to 100% control. Recognising that much of the cost of deploying traps and surveillance devices for pest management is people’s time, Bruce Warburton and colleagues discuss the utility of wireless networks for reporting device triggering. Bruce and colleagues also discuss how advances in thermal imaging camera technology can be put to use for animal pest surveillance.
Large gains in pest management can also be achieved by empowering end-users and stakeholders actively involved in operations to make the decisions themselves, about the best approaches to take for their circumstances, and how to optimise management impact (and subsequent benefit) from the resources that they have available. Dean Anderson and colleagues present a user-friendly web-based tool for rapidly assessing the success of an eradication attempt. Andrew Gormley and Graham Nugent detail a similar tool for use by OSPRI (TBfree New Zealand) vector control managers in their planning of post-control surveillance to demonstrate TB freedom – JESS (Just Enough Surveillance Sensitivity).
Finally, ground-breaking advances in the understanding of genetics being made in other disciplines, most notably human medicine, offer potential for a new set of tools and approaches for pest management. Not all of these necessarily involve genetic modification (GM). For example, Brian Hopkins and colleagues discuss how an understanding of the genetic code of pests and approaches from the pharmaceutical industry, can be used to develop new host-specific toxins for target pests. Damian Dowling and colleagues demonstrate laboratory proof-of-concept for a novel approach that has been in development just since 2012 – the Trojan Female Technique – based on the selective breeding of naturally occurring mutations in mitochondrial DNA that reduce male fertility.
The role as pest management researchers in New Zealand is to present the public and policy makers, stakeholders and end-users, with the best range of approaches to achieve the country’s pest management goals. Internationally, GM is offering large advances in pest management for both human health and conservation benefit. For example, the Gates Foundation is funding ‘Target Malaria’, a large program including genetic modification of mosquitoes to eradicate human malaria. Researchers in New Zealand are thus also starting to explore these options, to provide the necessary information based on which decisions regarding their use can be made. Brian Hopkins discusses how GM can be used in the laboratory setting, to rapidly accelerate the discovery of pest-selective toxins. To explore the use of GM to directly control animal pest populations in a safe and socially responsible manner, Landcare Research has joined a partnership of leading international agencies investigating all aspects of such approaches for rodent management – Genetic Biocontrol of Invasive Rodents (GBIRDd).
Through maintaining a broad research portfolio, and considering how different pest management approaches can best complement one another, New Zealand’s environmental goals such as Predator Free 2050 are likely to be achieved in a responsible and socially acceptable manner.
Dan Tompkins, Portfolio Leader Managing Invasives, Landcare Research