Agriculture scientists in Bangladesh have found a new pest -- fall armyworm -- that has destroyed maize and sorghum fields covering millions of square kilometres and devastated the livelihoods of farmers in Africa.
Bangladesh Agricultural Research Institute (BARI) last month detected the caterpillar in cabbage fields in Rangpur, Thakurgaon, Bogura and Jashore, while in maize fields in Bogura and Chuadanga, said Dr Syed Nurul Alam, director (planning & evaluation) at BARI.
The insect can damage 80 plant species, but it is a major threat for maize in Bangladesh. Other crops that could be under threat include tomato, cabbage, spinach, other leafy vegetables, sugarcane, lemon and wheat, he said.
However, crops damaged by the fall armyworms in the districts concerned would be less than one percent, Alam told The Daily Star on the sidelines of a workshop.
Centre for Agriculture and Bioscience International (CABI) and Saarc Agriculture Centre (SAC) jointly organised the programme on the threats of invasive species in Bangladesh in the city's Lakeshore Hotel yesterday.
The caterpillar will be a big threat to the South and Southeast Asian region if effective and immediate measures are not taken.
A native of the Americas, fall armyworm grows in tropical weather conditions. It was first found in South Africa in 2016 and later it spread to 43 other African countries.
Food and Agriculture Organization in a statement on June 27 this year said fall armyworm could leave 300 million people hungry in sub-Saharan Africa, having already infested maize and sorghum fields across 44 countries in an area of more than 22 million square kilometres.
In May, the caterpillar was found in the Indian state of Karnataka. Five months later, it was seen in Tamil Nadu, Telangana, Andhra Pradesh and West Bengal, according to the Indian media.
Alam said a moth of a fall armyworm can travel as far as 100 kilometres in just one night, and the female lays hundreds of eggs at once.
“We have a concern over fall armyworm, but we are not panicked because we have the experience of controlling almost similar types of pests, including common armyworm,” he said.
Farmers in Bangladesh already have the knowledge of controlling common armyworms using sex pheromone traps, Alam added.
In such traps, a capsule containing female sex hormone of insects is hung in a plastic bottle with one inch of soap-water and two holes in the middle of the bottle. Set up in crop fields, the bottle attracts male insects that drown in soap water.
Besides, there are insects that can kill the fall armyworm. Also, natural controls of several caterpillar pests can be used to check fall armyworm, said Alam.
Following the discovery of fall armyworm, the government has formed a national taskforce of officials, researchers and agriculture extension officials under the leadership of the agriculture ministry. It has been already working on how to best control the insect, he added.
“We already have factsheets about fall armyworms and distributed those among the agriculture extension personnel up to the union level.
“Massive monitoring of the pest is going on across the country,” Alam said.
Malvika Chaudhary, coordinator of Plantwise (Asia), a project of CABI, said fall armyworm is a big concern in South and Southeast Asia, which is suitable for the growth of the pest because of its warm and humid weather conditions.
Fall armyworm can damage 30 to 60 percent of crops as was evident in Latin America, she told The Daily Star. “We prefer biological way of controlling the fall armyworm.”
Use of chemicals in controlling the pest raises the risks of food contamination and pesticide resistance.
The CABI is currently working in 10 districts to train the field level officials on identifying the pest.
Nasreen Sultana, senior program specialist (horticulture) of SAC, said they were planning to take up a regional programme on control of fall armyworm.
India, Bangladesh, Pakistan and Sri Lanka are among the South Asian countries that face higher risks of fall armyworm outbreak as they have long summer season.
“We need to control the pest before there is an outbreak,” she said.