Fall Armyworms bigger threat to maize in summer: Experts

Fall Armyworms (FAW) have been a menace to maize crops across the globe for years. And they have been spreading across Bangladesh at an alarming rate too, said experts at a discussion on Wednesday.

Bangladesh first found the presence of FAWs in a handful of districts back in 2018, but now, the pest has spread to every district. Clearly, the pest is most active during summer, as colder temperatures during winter prevent them from reproducing efficiently.

The damage caused by FAWs to Bangladesh's maize crops have been minimal so far, because the country cultivates maize primarily during winter. Even so, concerns remain as FAWs can now also be found on cabbages, tomatoes, paddy and tobacco crops in smaller numbers, they said.

Experts made the disclosure at a roundtable, entitled "Fight against the FAW in Bangladesh", jointly organised by USAID and Feed the Future (FTF). They noted that FAWs pose a much lower threat to maize during winter.

Data collected by the Bangladesh Wheat and Maize Research Institute reaffirm that on average, FAWs harm 5-6% of the maize crops during winter, but damage up to 20-22% of the yield during summer.

During the keynote presentation at the event, International Maize and Wheat Improvement Center's Senior Scientist and Systems Agronomist Timothy Krupnik said, "The pest can reproduce most efficiently when the temperate is around 25 degrees Celsius.

"In a favourable environment, Fall Armyworms can reproduce very quickly. A female insect can lay up to 1,500-2,000 eggs. This is why the infestation is being considered alarming.The pest has been found damaging more than 300 crops across the globe."

Speakers at the programme added that a project, "Fight against the FAW in Bangladesh", was launched back in 2019 with funding from USAID.

Under the project, farmers and field officials of the Department of Agricultural Extension are being trained to tackle the pest.

The speakers further said farmers should not spray pesticides indiscriminately on their crops once they find the presence of FAW because too much pesticide can kill insects that are beneficial to crops, which could result in a lower yield.

The experts recommended using effective pesticides once to purify the seeds, and later to curb the infestation if necessary. A fact sheet on Integrated Pest Management has also been prepared in the Bangla language and distributed among farmers under the project.

It should be noted that FAWs have so far destroyed 13.5 million tonnes of maize crops in Africa before their presence was identified in Asia.

John Smith-Sreen, director of the Economic Growth Office at USAID and its Activity Manager Mohammad Shibly were present at the discussion, among many others.