Why every farmer should know about ‘Fall Armyworm’
What is Fall Armyworm (FAW)?
The ‘worm’ is a moth native to tropical and subtropical regions of the Americas, which feeds on more than 80 plant species in its caterpillar stage. This includes some of the world’s most important crops – particularly maize (corn), but also rice, sorghum, millet, sugarcane, cotton and vegetables.
FAW spreads quickly: As a moth it can fly up to 100km a night and females lay up to 1,000 eggs in their lifetimes. International trade routes have also enabled it to spread. Several generations can feed off one crop during a growing season. It attacks maize from germination to harvest.
Where is it now and what’s the impact?
It’s been active across North, Central and Southern America for decades, but arrived in Africa in early 2016 where it’s devastating crops, causing $3bn of damage.
In July 2018 it spread to Yemen and India, before moving to South East Asia. It was detected in China’s southern Yunnan province in Jan 2019, and has now reached Henan province, 2,500km away further north. It is now in more than half of China’s 34 provinces and is predicted to move further northward as summer temperatures increase and crops develop in major growing areas in Central China, the North China Plain and North East China.
Area’s where China grows maize – FAW’s preferred food – have climatic conditions the worm thrives on and farmers have planted more crops than usual because of current limits on imports. However, with Swine Fever having led to a large cull of pigs, demand for feeding the herd with corn or cereals may fall.
For countries where FAW exists, the value of crops at risk is $13.3 billion, according to the University of Maryland. When unchecked, FAW has the potential to reduce maize yields by between 20 -50%.
What might happen next?
Experts fear FAW could spread from Africa and Asia to Europe. In China, the most populace country in the world, some say it could move across the whole of the grain producing regions within next 12 months.
What are the solutions?
In the US, farmers manage FAW by planting crops earlier, before the caterpillars hatch, using resistant GM crops, predators, and insecticides. Where technology is less affordable, farmers can manually remove FAW, manage plantings and use botanical insecticides.
But resistance to chemical pesticides has been detected. Two active ingredients remain effective – Acephate and Novaluron – and ADAMA has been treating multiple crops for FAW in several countries.
In Brazil, for example, Voraz® – Novaluron + Methyl mixture– has been an effective management, even controlling resistant Spodoptera species, in several crops.
PlethoraTM – Novaluron + Indoxacarb mixture– is also a broad spectrum lepidopteran insecticide registered and used in India, South Korea and Indonesia.
In China, the Ministry of Agriculture and Rural Affairs has announced 25 products that can be used until Dec 31, 2020 to combat FAW – this includes ADAMA’s acephate.
The pest called Spodoptera frugiperda or ‘Fall Armyworm’
In its caterpillar stage FAW feeds on more than 80 plant species