Northlanders optimistic work being done to manage invasive pest fall armyworm

Fall armyworm wreaking havoc on maize and sweetcorn crops. Photo / Foundation for Arable Research

Northlanders affected by fall armyworm are optimistic work is finally being done to mitigate the fallout from the invasive pest.

The Ministry for Primary Industries (MPI) recently announced a “fresh arsenal” in the battle against fall armyworm, a plant pest that destroys grasses and cereals, especially sweetcorn and maize.

Biosecurity New Zealand Deputy Director-General Stuart Anderson said it is investing in the development of “an integrated pest management approach” to safeguard New Zealand’s maize and sweetcorn industries.

MPI has teamed up with Foundation for Arable Research (FAR), Process Vegetables NZ, Vegetables NZ Inc, and growers on management and mitigation strategies to help reduce production losses and enhance resilience to the invasive pest.

“Together we’ll develop some really good tools for growers, including establishing surveillance networks on a national scale,” Anderson said.

Fall armyworm is believed to have blown over to New Zealand from Australia after a cyclone in 2022.

The same year, the Northern Advocate reported farmers in the Far North were deeply concerned the pest was annihilating their maize crops, which hiked the cost of growing the essential feed while also producing devastatingly low yields.

However, Biosecurity New Zealand said fall armyworm couldn’t be eradicated and was here to stay.

Industry partners are now shifting the focus to long-term management of the pest.

Mark Dunham, from Northland Seed and Supplies, said there had been a lot of uncertainty over the last two years around how much of an impact fall armyworm would have and the control measures farmers should take.

“Everyone has been unsure, MPI, farmers, everyone. It’s been a challenge to overcome.

“In hindsight it hasn’t come to a lot across Northland. There’s been half a dozen farmers impacted economically each year.”

Dunham said the investment from MPI and other sector groups was “positive”.

“Initially it was hard for everyone to get information, but it’s coming through and farmers are more comfortable with it now.

“The more tools they can provide the better it’s going to be.”

MPI recently announced a fresh arsenal in the battle against fall armyworm.

MPI said fall armyworm has the potential to impact 72,490 hectares of maize, with an estimated value of over $480 million and 3320 hectares of sweetcorn production, with an export value of $36.9m.

FAR biosecurity officer Ashley Mills said it wasn’t known what the full impact of fall armyworm would be in the future.

“It depends largely on our winter temperatures and suitable host plants in the absence of maize and sweetcorn,” Mills said.

“For instance, in areas with warmer winter temperatures such as Northland, the insect has the capacity to overwinter and survive all year round.

“With warming temperatures, we might expect the problem to grow year on year.”

FAR and Vegetables NZ Inc will host information and tools for fall armyworm management on their websites.

This will include modelling, distribution maps, guidelines, and training videos. FAR will also host workshops over winter, tailored to each region.

MPI will contribute up to $300,000 over three years to the $630,000 project through the Sustainable Food and Fibre Futures fund.

Mills said part of the research would be to identify gaps of knowledge around the winter growing season and dispersal of fall armyworm.

“We’ll produce models and come up with early warning tools for agronomists and growers, so they understand when they need to employ their most intensive management strategies.

“There’s no one-size-fits-all solution, and approaches may vary according to factors such as region, climate or soil type.

“In most cases, encouraging beneficial insects will work, but, in more problematic regions or localities, insecticides might be needed, and the timing of application will be important.”

Jenny Ling is a news reporter and features writer for the Northern Advocate. She has a special interest in covering roading, lifestyle, business, and animal welfare issues.