Fall Armyworm attack: Rwanda fights it back successfully

The country couldn’t predict the pest attack owing to few resources, but it successfully minimised its impact within a year of identifying it

By Christophe Hitayezu
Published: Wednesday 27 February 2019
Fall Armyworm attack
Until 2016, Fall Armyworm was constrained to the Western Hemisphere. Until 2016, Fall Armyworm was constrained to the Western Hemisphere.

What was an unknown pest attack few years ago in Rwanda and destroyed more than a tonne of maize crop per hectare, became a Fall Armyworm outbreak two years later and spread to all 30 districts of the country.

Maize farmers under COOPROMASA, a cooperative in Rwanda’s Gatsibo district, harvested less than three tonnes per hectare of the cereal grain instead of the usual 4 tonnes per hectare in a season.

The pest, which had first hit Rwanda’s Mushishito marshland in Nyamagabe district, infested 17,521 hectares of maize out of 46,403 hectares planted by April 2017.

Since then the country’s Ministry of Agriculture and Animal Resources (MINAGRI) has been alerting farmers about the pest that damages almost 80 plant species. It attacked 91.7 per cent of maize and sorghum planted in Nyamagabe district and all of the maize in Nyanza and Muhanga districts. Due to limited research and systems for early detection and minimising impact, the outbreak spread quickly.

Spread of the pest

Until 2016, Fall Armyworm was constrained to its native region of origin — the Western Hemisphere (from the United States of America to Argentina). However, in January 2016, the pest was found in Nigeria and it has since spread at an alarming rate across Africa.

Otto Vianney Muhinda, Food and Agriculture Organization’s (FAO) assistant representative in Rwanda, said food and seed trade between countries and continents could have spread the pest faster.

“A visible number of Fall Armyworms are being produced by flying moths, which are hard to see as they move at night. They live for 20-30 days and the females can lay around 1,000-2,000 eggs that give crops destructive caterpillars, most of time into the whorl of the crop,” said Muhinda.

A moth can fly for more than 800 kilometres leaving eggs on its way.

Meanwhile, the Arabic region of the continent is unaffected as the pest can’t survive the high temperatures of the Sahara Desert. Also, Lesotho is the only unaffected country in the Sub-Saharan region owing to its cold weather conditions.

Donald Zulu, a lecturer and researcher at the Copperbelt University in Zambia told the Inter Press Services that climate change may complicate the pattern of infestations. “Outbreaks of Armyworm are highly dependent on seasonal patterns of wind and rainfall. With global warming, the weather pattern in Africa will continue to change, which could mean fewer Armyworm outbreaks,” he said.

Awareness proves effective

Awareness among farmers has helped minimize the impact while not affecting food security in the country. Other crops like beans, Irish potatoes, bananas, rice, wheat, soybeans, and cassava among others are being planted more.

Claver Ngaboyisonga, a researcher at Rwanda Agriculture Board, said although no substantial research has been done to know how the insect made its way into Africa, it is important to be vigilant about it to reverse the impact.

“No research has been conducted yet on how the Fall Armyworm crossed the ocean to Africa after many years in America, considering the long distance between the two continents. It is hard to outline factors of transmission, even if the adult moth can travel up to a hundred kilometres per day, it can’t cross the Atlantic Ocean. But most importantly, the main concern is to recognise that it is here and damaging our crops,” said Ngaboyisonga.

Good practices

While the MINAGRI said the country lost more than 10,000 tonnes of maize in 2017, some great and fast efforts helped minimise that loss in 2018.

“Most of the farmers have learnt how to deal with it by collecting and destroying caterpillars and young moths as well as by spraying pesticide on the infected maize. But, the Fall Armyworm is still a threat. We need farmers to be prepared to fight it early enough before it wreaks havoc,” Minister of Agriculture and Animal Resources Gérardine Mukeshimana said.

Rwanda made effective communication a key to their operation against the pest. In April 2017, the Rwanda Defence Force joined the residents, local leaders and experts in spraying pesticide on affected plantations.

“No single solution would be effective in managing Fall Armyworm on its own. We, however, need not completely reinvent the wheel. There is a lot of expertise and knowledge in the continent and elsewhere. But the farmer has to be central to all our efforts,” said Hans Dreyer, director of FAO’s Plant Production and Protection Division.

In March 2018, the Rwandan government, in collaboration with FAO, launched a campaign to install pheromone traps to catch moths. “Males follow female odour for reproduction. We used a solution with the same odour to attract and collect males in traps,” said Muhinda.

More than 98 per cent of maize farmers in Rwanda and most African countries are small land holders, growing maize on less than two hectares of land and saving seed to plant the next crop.

That’s why farmers have been asked to visit their crops regularly to observe if it has caterpillars, remove them by spraying pesticide. Pesticides are more effective on eggs as caterpillars grow resistance to it.

Since the worms posed a threat to 30 per cent of his yield, John Muvara, a farmer who holds a 12-hectare land in Nyagatare District, said he decided to opt for pesticides, which cost him more than $1,100.

“I lost only about 1 per cent of my maize yields because I started controlling the pest through picking them and using pesticide on them. I sprayed the pesticides three times using around 3-4 litres per hectare,” he said.

On how to ensure the attack again doesn’t turn into an outbreak, Nshimiyimana Jean Claude, an agronomist at the International Potato Centre, said farmers should be well equipped and aware of ways to control the pest.

“Although pesticides, such as Rocket, are reliable, farmers must have more options, including biological control methods, where a farmer may use palm oil to attract ants which attack Fall Armyworms,” said Claude.

(This is a part of a series of stories tracking the world’s deadliest pest attack)

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