Destructive fall armyworm now invading India

By Joan Conrow

August 9, 2018

With farmers across the African continent still reeling from the devastation wrought by fall armyworm, news has come in that the voracious crop pest has now invaded India.

Researchers first spotted fall armyworm (FAW) May 18 in maize (corn) fields owned by the College of Agriculture in Shivamogga. But reports of the discovery only surfaced recently, when the Indian Council of Agricultural Research (Icar) issued a pest alert.

An investigation by agricultural officials and researchers found FAW in other districts, including Chikkamagaluru, Chitradurga and Davanagere, where 40 to 70 percent of the crops were infested.

They say FAW could be present, but undetected, elsewhere in the nation. Now that the pest has a foothold in India, scientists at the Centre for Agriculture and Biosciences International (CABI) warn it could easily spread to the neighboring countries of Nepal, Bangladesh and Pakistan, putting maize production on the entire Asian continent at risk. It is expected to move rapidly into the states of Tamil Nadu and Andhra Pradesh — India’s hubs for hybrid maize seed production.

The question now is how to control the moth and its hungry larvae before Indian farmers suffer the same serious losses that have been reported in Africa, where FAW has spread to 44 countries. There, FAW has persisted through two growing seasons, prompting farmers in some nations to incur greater debt, increase pesticide use and even abandon maize cultivation.

“A fast response is important as this pest spreads quickly,” said Dr .Gopi Ramasamy, CABI’s country director for India. “It’s likely fall armyworm arrived in India from Africa through human-aided transport, although natural migration is also a possibility since it’s able to fly hundreds of kilometres in one night on prevailing winds.”

A recent investigation by CABI in 12 African nations found that FAW has the potential to inflict yield losses averaging 21-53 percent, destroying 8.3 to 20.6 million tonnes of maize valued at US$2.5-US$6.2 billion annually.

Maize is a staple crop essential for food security in large parts of Africa and Asia. But the FAW isn’t fussy, feasting on some 186 different plant species, including grain, vegetables, soy beans, sorghum, cotton and grasses.

In Africa, field trials of genetically modified TELA corn, developed under the Water Efficient Maize for Africa project, showed resistance to FAW thanks to the presence of the Bt gene, which was originally intended only to control the corn borer.

In response, some famers and agricultural leaders have called for adopting GM crops more rapidly to help combat the pest before food security is seriously impacted. Though India has achieved great success with GM cotton, anti-GMO activists have blocked attempts to approve other GM crops.

The Food and Agriculture Organization of the United Nations noted that Bt maize has successfully resisted FAW in the Americas, and “may be one of the options for control of this pest in Africa.” However, “more work needs to be done” in regard to field trials and collecting data. In Brazil, the main strategy for controlling FAW is the use of Bt maize and Bt cotton, though US researchers say Bt is most effective when paired with biological controls and other traditional pest management practices.

While African farmers wait for the approval of GM maize they have been forced to rely on additional pesticides. The Institute for International Tropical Agriculture is collaborating with other partners in Africa to develop additional management solutions, including low toxicity biopesticides, biological control involving natural enemies and entomopathogens, varietal tolerance and low-cost agronomic practices.

“There are lots of ways to kill the fall armyworm, but getting them deployed cost-effectively is the issue,” said Dr. Roger Day, who runs CABI’s program for action on invasive species. Indian farmers too, it seems, will soon need all the help they can get.