Although swarms of locusts entered Nepal on Saturday, there haven’t been reports of the pest ravaging crops in the country.

But Nepal is not out of the woods yet as bigger swarms could come from India in the next few days.

“We have not received reports of significant damage caused by locusts. But we can’t say the danger has now passed,” said Sahadev Prasad Humagain chief of the Plant Quarantine and Pesticide Management Centre under the Ministry of Agriculture, during a press conference in Kathmandu.

Swarms of locusts, known for their voracious eating emerged in the deserts of West Asia, and have come to South Asia by hitching rides on prevailing westerly winds. The pests, which are around 10mm to 70 mm in size, can eat their own weight in food every day, and thrive in places where there’s no shortage of rainfall and green vegetation as they breed rapidly.

“Currently the wind is blowing towards Nepal [from the south] and it is likely to continue for a few more days,” said Humagain, who is also the coordinator of the government-formed task-force to deal with locust invasions.

According to the UN’s Food and Agriculture Organization, the swarms can be traced to the cyclone season of 2018-19 when heavy rains in the Arabian Peninsula allowed unprecedented breeding. Locust swarms have spread out into East Africa, the Middle East and South Asia. Another swarm has been devouring crops in South America

“If there are locust swarms still remaining on the Indian side along the Nepal-India border, they might enter Nepal with the prevailing winds,” said Humagain.

He added that the swarms of locusts, which entered Nepal from India on Saturday, are small in size and so far there haven’t been reports of significant damage to crops.

In Pakistan, from where the insect entered South Asia, the government declared a national emergency after swarms devoured swathes of vegetation across the country.

However, another swarm entering Nepal could wreak havoc, said Humagain as a bigger swarm is reported to have been moving towards New Delhi from Rajasthan. Wind coming into Nepal from the south could bring the insects to Nepal.

“If Indian authorities control the swarm in India, then only small groups could make it into Nepal. But if the larger swarm enters Nepal, it will cause a lot of problems,” Humagain told mediapersons. “We have to remain alert.”

On Saturday, swarms of locust, first seen in the Tarai, moved to various hilly districts as well. The swarms are believed to have broken off from a larger unit in India and were likely blown towards Nepal with the wind blowing north from south.

On Sunday, the swarms reached hilly districts of Sindhuli, Kavre, Ramechhap, Syangja, Palpa among others. There were reports of minor damage to maize in Sainamaina Municipality, Rupandehi.

Ram Krishna Subedi, senior plant protection officer at the Plant Quarantine and Pesticide Management Centre, the swarms that entered Nepal are constantly breaking away and reaching different places. Locusts that entered from Bara are reported to have been spotted in a forested area in Makawanpur. Another group that entered from Rupandehi is reported to have reached Butwal and Kapilvastu.

“Initially, it was said that the chances of locusts entering Nepal were low because of the typical weather conditions and the direction of the winds blowing from east to west [during the active monsoon period],” said Sunil Aryal, a senior scientist at Entomology Department of Nepal Agricultural Research Council (NARC).

“But as the wind deviated from its normal direction and started blowing toward the north, the wind brought them here. Meteorologists have said the sudden change in wind direction took place after 24 years.”

On Sunday, the weather forecasting officials issued a special bulletin saying that wind is expected to change its direction in the next few hours, taking these swarm further west. Regular monsoon rainfall is also expected to slow them down, but help them breed.

Following the arrival of locusts in the country, the Ministry of Agriculture Ministry organised to chart a strategy to control their spread.

Acknowledging the possibility of a bigger invasion, the meeting decided to work collectively with all levels of government and the department of hydrology and meteorology to keep track of their movement.

Subedi said that farmers, and local and provincial governments have been assigned various jobs to prevent the spread of the pests.

“Farmers should inform government authorities when they see swarm movement in their field. They are also advised to make loud noises or produce smoke,” said Subedi. “Local and provincial governments should be prepared to use insecticides. They should also keep track of locust movement.”

The centre has also recommended a set of five insecticides to kill the swarms and directed line agencies to ensure the availability of these insecticides at the local level.

“Local and provincial governments have also been asked to keep fire trucks on standby to spray insecticide in case larger swarms enter the country,” said Subedi.

Meanwhile, experts say that events such as locust invasions should come as a wakeup call for Nepal to not just focus on the melting of the Himalayas when it comes to climate change.

Madhukar Upadhya, a watershed and climate change expert, said that the arrival of locusts even during the rainy season when wind moves from the east to the west indicates ecological changes related to climate change.

“For years, we have remained focussed on the Himalayas and melting of snow while talking about climate change. The unprecedented arrival of locusts are part of a changing ecology and a changing climate which we have not paid enough attention to,” said Upadhya.

“We need to study the micro-level impacts of climate change on the ground, which is not possible by one ministry. Changes that we have not paid attention to—such as the swarm invasion—may wreak massive havoc in the years to come.”