Aerial invaders research programme

Protecting Aotearoa from aerial invaders in a changing climate is a five-year research programme (October 2023 to October 2028) focused on closing the airborne long distance dispersal pathway – a hole in our biosecurity net. Scion is leading the MBIE-supported programme.

The programme aims to manage the aerial pathway of pest movement by developing a system to monitor airbridges that form under certain meteorological conditions before pests and pathogens arrive. It will modernise wind trajectory modelling, study airbridges between land masses such as Australia and New Zealand, and fill knowledge gaps on aerial invader survival/mortality during the long- distance migration, and the atmospheric conditions that they face en route.

Background

In New Zealand, and globally, there is a gap in biosecurity defenses. This gap allows aerial invaders (insects/pathogens) to reach New Zealand via the wind and spread within New Zealand regardless of their arrival mode. There are currently no effective tools to manage this pathway of pest movement and the hole this leaves in our biosecurity net will widen as climate change brings more extreme weather events.

Atmospheric Dispersion Modeler Dr Ilze Pretorius bid for the research programme funding.

Research aims

The programme aims to develop a novel model, integrated Aerobiological Surveillance and Prediction System (ASaP) and address critical knowledge gaps to do this. It will:

  • Modernise outdated conventional wind trajectory modelling by incorporating the strengths of new scientific advances in long-distance atmospheric transport.
  • Understand which land masses aerial invaders come from, how frequently ‘airbridges’ form, and how the frequency and locations of these airbridges are changing due to climate change.
  • Develop new knowledge about how passive aerial invaders move from airbridges to the ground.
  • Fill knowledge gaps on aerial invader survival/mortality in extreme atmospheric conditions they experience during long-distance transport.
  • Partner with Māori kaitiaki to quantify a baseline of aerial invader arrivals to monitor change.

Research aims include

Long-distance transport

Combine existing atmospheric dispersion modelling and analysis to develop a powerful new tool for atmospheric transport modelling and develop a long-term (30-year) dataset of airbridges connecting New Zealand and other land masses to determine where aerial invaders are coming from and could come from in the future.

Vertical coupling

Quantify how particles, such as pathogens and insects, move between the upper atmosphere and earth’s surface to help determine the likelihood of survival and consequential deposition of aerial invaders being moved by connecting airbridges between landmasses.

Atmospheric survival data

Document the atmospheric extremes aerial invaders are exposed to during trans-Tasman transit. Use flight experiments to assess the survival of flying moths. Record survival of pathogens exposed to the atmospheric extremes of temperature and UV.

Preconditioning, establishment, and surveillance

Undertake two years of surveillance on the west coast of Taranaki to establish a baseline database of insects and pathogens that reached New Zealand via aerial invasion. Live interceptions of invaders will be invaluable to inform the airbridge modelling. The learnings from the entire project will be shared with tamariki in the region through a community outreach and educational project with partners Taranaki Mounga Project.

ASaP integration, validation, and prediction

Integrate knowledge gained during the programme into the ASaP model to provide surveillance of aerial pathways. Automated alerts can be sent to warn stakeholders/communities/kaitiaki at times of high risk meaning the likelihood of new aerial invader establishment could decrease, mitigating risks to national goals for carbon sequestration, the transition to a low-emissions/climate-resilient economy, GDP growth across primary sectors and the protection of the conservation estate and many ecosystem services.

LCS airbridge by month: Lagrangian coherent structures showing the pathways that could result in a fall armyworm incursion from Australia to New Zealand.

Benefits to NZ

Over the past decade, New Zealand has battled multiple aerial invaders which are now established pests (e.g. myrtle rust, fall army worm). There are many more on our doorstep, circulating in Australia/Asia-Pacific. Preventing establishment of just one serious pest could recover programme costs 10 to 100 times (NZ$0.125b-1.25b) through avoided losses in the forestry and/or horticultural sectors, and maintenance of carbon sequestration.

ASaP will be run in hindcast to inform optimal surveillance locations, in forecast to predict invasions before they occur, and in hindcast and forecast to predict where spreaders could travel within NZ after their arrival.

Post-graduate Research Opportunities

The programme will be providing scholarships for a number of postgraduate students to the University of Canterbury in the Engineering, Statistics and/or Maths and Environment Schools. If you have an interest in furthering your study in aerobiological modelling, the science of moth flight, or Bayesian network modelling, please keep an eye out for vacancies on the University of Canterbury website.

The Aerial Invaders research programme is funded by the Ministry of Business, Innovation and Employment with co-funding from Te Uru Kahika – Regional and Unitary Councils Aotearoa and The Foundation of Arable Research.

Contact

Jessica Kerr, Forest Entomologist