Fall Armyworm infests India

For the first time Khemo Baghel, a farmer of Bade Chakwa village in Chhattisgarh's Bastar district, took up maize cultivation in January 2019. He dug a borewell in his farm and was convinced that the return from maize would be much better than any other crop.

But when hardly any seed had sprouted, he saw some keedas (worms) slowly colonising his farm. "I found them one fine morning. There was no trace of them the previous day. I think they landed at night," he says.

Within two months, his farm, though wears a lush green hue, is gripped by the worms. He has already lost 30 per cent of his maize crop. "Don't know whether it would survive," he says.

Uncertainty hovers over the village as other maize farmers report the never-seen-before insect invading. Of late, local agriculture scientists and extension officers frequently visit Bade Chakwa and other neighbouring villages. And they are also puzzled. But, by this time, the unidentified invader has a local name: American keeda.

Worming their way in

In January 2019, Chhattisgarh became the latest state in India to report infestation of Fall Armyworm (FAW), locally being referred to as American keeda.

In just nine months since Fall Armyworm was spotted in Karnataka in last June, it has invaded crops in more than 10 states. As if taking a pre-scripted route, Fall Armyworm infestation has spread from Karnataka to all southern states, then to western Maharashtra and Gujarat and now to the eastern Indian states.

Other than fast advancement, the pest is also attacking new crops. Though it is being detected mostly in maize crops — a preliminary calculation estimates that it has affected nearly 1,70,000 hectares of maize crops — there have also been reports from states where it has infested paddy, sugarcane and sweet corn.

Maize is the third most important cereal crop in India after rice and wheat. It accounts for 9 per cent of the total food grain production in the country. The up-to-2-cm-long pest "accidentally" landed in Africa in 2016 from its native Americas, almost after 100 years. Since then, it has wreaked havoc in over 50 countries in Africa and Asia ravaging crops, especially maize.

Destructive march

Entomologists CM Kalleshwara Swamy and Sharanabasappa first detected FAW in research fields of maize crop at the University of Agricultural and Horticultural Sciences, Shimoga, Karnataka. Just before monsoon setting in last year, a few maize farmers from Chikballapur area of Karnataka reported a pest infestation to AN Shylesha, a scientist at the National Bureau of Agricultural Insect Resources (NBAIR) affiliated with the Indian Council of Agricultural Research (ICAR) in Bengaluru. Analysing the farmers' initial observations, Shylesha took it as the true armyworm infestation.

But the severity in the infestation led him and his colleague SK Jalali to conduct a survey of the affected fields and collect samples in July 2018. The next month came to the confirmation, and a challenge in the form of the country staring at its first FAW infestation.

"The spread of Fall Armyworm is nothing like we have ever seen with any pest before. We have faced pestilences such as a wheat blast or the Maize Lethal Necrosis. But in all the previous cases, the incidents were mostly limited to a few countries and also limited to a single crop. With Fall Armyworm, the threat is much bigger, in terms of the extent of damage caused to both the crop varieties and the area," says BM Prasanna, director, CGIAR Research Programme on Maize.

Fall Armyworm has already destroyed large areas of maize in Africa since it first landed there in early 2016 leading to economic losses of up to $5.5 million per year from 10 of the highest maize producing countries of Africa, according to an estimate by the Food and Agricultural Organization (FAO) of the United Nations (UN). In fact, FAO has already declared FAW as a food security threat in the African continent.

In India, FAW found suitable environmental conditions and appropriate host plants which accelerated its spread from Karnataka to neighbouring states. Malvika Chaudhary from the Centre for Agriculture and Bioscience International (CABI), says, "Karnataka and Tamil Nadu are currently witnessing greater infestation. But taking into account environmental conditions and availability of host species the Eastern side of India is more vulnerable to the pest in the near future."

(The views expressed are strictly personal)