Focus/Spotlight

Invasion of the fall armyworm

By Skandha Gunasekara

Inefficiency in government pest control methods has resulted in the mass spread of an invasive species in the country with almost 60% of Sri Lanka’s corn crops being already decimated by the fall armyworm.

The fall armyworm is in fact the larvae stage of the fall armyworm moth (Spodoptera frugiperda), commonly known in the country as the “sena caterpillar”, and has the ability to destroy hundreds of acres of cultivation overnight, and could affect over 180 varieties of crops, including paddy, maize, sugarcane, green gram, and other vegetables and fruits.

It has a preference to maize, which is a main staple crop around the world.

The caterpillar, originating from the Americas, was first reported in Africa in 2016 and has since spread to over 40 African countries and devastated hundreds of thousands of acres of crops.

Declared as a severe risk to world food security, it prompted the United Nations Food and Agriculture Organisation (UNFAO) to invest more than $ 9 million from its regular budget and to mobilise $ 12 million on FAW control programmes.

The fall armyworm menace was first reported in India in May last year in the state of Karnataka and soon spread to other states such as Andhra Pradesh, Maharashtra, and Telangana, as well as Tamil Nadu – the closest state to Sri Lanka.

Origin of the species questioned

Leading environmentalist lawyer Jagath Gunawardana, speaking to The Sunday Morning, said that this was clearly an agricultural pest new to Sri Lanka.

“This is a new species. We already have the rice armyworm in Sri Lanka. I cannot be certain whether the fall armyworm was already here in small numbers and something caused a population boom or if it had arrived entirely from another country,” he said.

He went on to say that this species of armyworm was particularly dangerous to crops because of its vast dietary preference.

“It has a wide range of foods that it consumes as part of its diet. Pests like the rice armyworm only damage rice crops and one or two other crops.

But the fall armyworm is not limited to one or two preferences. It will gorge on over 180 different types of crops, vegetable, and fruits, and is therefore a threat to our food security.”

Furthermore, he pointed out that the fact that the fall armyworm had a wide ranging diet would make eradication quite challenging as well, since there was no option of curbing its spread by limiting its food supply.

Situation at hand in Sri Lanka

All Island Famers Federation National Organiser Namal Karunaratne told The Sunday Morning that the caterpillar menace had first been reported in the Damana region in the Ampara District in June last year.

“Corn plantations in the Damana region were the first to be affected, but now it has spread to other parts of the country. Corn plantations in Anuradhapura, Polonnaruwa, and Kurunegala have also been affected.”

He said that the danger lies in the moth’s ability to spread across vast swaths of land in a short period of time at a high rate of reproduction.

“The moth can travel up to 100 km with the help of the wind. That is why it reached Anuradhapura soon after devastating crops in Ampara. Adding to that, the female lays over 200 eggs. Because of its high numbers, we call it the sena dalambuwa.”

In addition, Karunaratne said that the caterpillar’s appetite appeared to be unending.

“When I went to one of the affected corn fields in Ampara for a site visit, I was able to see the creature. It was eating a leaf in my hand, and while it was, it was also excreting refuse from its rear. It is nonstop. The leaves of the crops in that field looked like it had been put into a blender.”

He went on to say that the pest had now shifted from corn to other crops such as paddy and vegetables.

“Over 60% of corn cultivations in the Ampara District have been completely destroyed, and similar reports are coming from other corn cultivating areas. I would say that more than 60% of the countries corn cultivation has been completely destroyed,” he said, adding that paddy cultivation in Polonnaruwa and Anuradhapura too were being affected.

Karunaratne ascertained that Rs. 1 billion in losses have been incurred as a result of the damages caused by the fall armyworm.
With regard to how it arrived in the country, Karunaratne said that he was uncertain about it, but that it had most probably arrived through imported fruits or vegetables from India.

Need for prompt and proper solutions

However, Karunaratne charged that the Government’s efforts to curb the pest have been largely inadequate.

“The current precautionary methods and advice on eradicating this menace provided by the Department of Agriculture are insufficient. The pesticides used will also have an effect on future crops, as they contaminate the soil. This will soon cause a food shortage and crisis in the country,” he said.

Karunaratne said that the Government must look at the issue as a national problem and take quick and firm actions.

“The Government should classify the affected areas as disaster zones, and the Cabinet should allocate separate funds for the purpose of addressing this issue head-on, without wasting any more time.”

He said that various methods such as destroying the eggs must be considered.

“We could also look at introducing an animal that feeds on this caterpillar or the moth. But we must make sure that the animal does not harm the environment in some other way.”

He went on to say that the newly-appointed Minister of Agriculture was avoiding the issue.

“Several media organisations reached out to me on this issue and they all said that when they tried to contact Minister P. Harrison, the Minister would say that he was at a meeting and avoid answering questions.”

Horana Fruit Research Institute Principal Agriculture Scientist (Fruits) Shayama Pushpakumari said that the institute had carried out awareness programmes in affected areas and informed farmers of what steps should be taken to tackle the issue.

“We advised them on the integrated pest management (IPM) method to curb the spread of this insect.”

She said that the IPM includes steps such as putting ash on the crops in the morning, killing the caterpillar by hand, using pheromones to kill the moth, using low-urea fertiliser, and the use of a number of pesticides and insecticides.

“The problem with using these chemicals in corn is that the caterpillar is within the corn cob itself, so the chemical cannot be used in such an instance.”

With the fall armyworm spreading and the apparent dragging of feet of the Government in addressing the issue, subject-matter experts such as Namal Karunaratne assert that Sri Lanka is heading towards a serious food crisis.

Several attempts by The Sunday Morning to contact the Minister of Agriculture were made, but to no avail.