Swarms of desert locusts arrived in India earlier than their usual migration cycle. This, however, is not the last swarm and more waves of migration will occur in July as hopper bands from East Africa are expected to move northwards and cross over the Arabian Sea into Sindh (Pakistan), Gujarat and Rajasthan.
Keith Cressman, senior locust forecasting officer of the Food and Agriculture Organization (FAO), said that the next swarms of desert locusts will fly with aid of southwest monsoon winds to cross the Arabian Sea to once again come into drier areas of Rajasthan.
The senior officer of the United Nations organization said that the movement of swarms was expected since late last year due to developments in East Africa and the Indian government was given warnings on the locust invasions. “Last year there was very good breeding in India, Iran and Pakistan. At the moment, populations are moving out of spring breeding areas, from southwest Pakistan and Iran. Normally, they invade at the end of June. But, they are here a month in advance due to drier conditions in Iran and southwest Pakistan,” Cressman said during a Centre for Science and Environment webinar on desert locusts.
“They prefer to arrive in Rajasthan ahead of the monsoon but they don’t like the habitats in Central India or further to east, the wind conditions and lack of food is forcing them to move ahead,” he explained.
This is the second time this year that locust swarms have been seen. Early in January, many districts of Rajasthan witnessed locust swarms and farmers suffered heavy losses as they devoured standing Rabi crops.
Swarms will move back to Rajasthan after monsoon sets in
Cressman said that there was no need to panic or get alarmed about the swarms about invasion of locusts across several states. The senior FAO officer said that desert locusts do not prefer regions that are not dry. “India is not going to be flooded by desert locusts in all of its states. They are not happy to be in non desert areas in Madhya Pradesh, Maharashtra and Uttar Pradesh. This is not their natural habitat as it is not suitable for their breeding and there are no desert sands. They will be struggling. They have got into a rare situation that is not suitable for them,” Cressman said.
He added, “They are waiting for the onset of monsoon in Rajasthan. They will be in a holding pattern until monsoon and they will be move back to Rajasthan with the wind directions. Since they cannot fly against the winds, there are low chances that they will move into southern India. Prevailing wind pattern is west to east.”
Digging trenches, making noises an alternative to pesticides
When asked about the methods of locust control other than spraying of pesticides, Cressman said that farmers can try digging trenches and make noises to scatter them away from the immediate area of their fields.
“There are bio-pesticides but farmers don’t have access to the alternatives or even the chemical ones at times. For these reasons, FAO does not encourage locust control by farmers. Desert locusts prefer undisturbed areas their hopper bands march. Farmers can dig a trench around their fields that serve the function of moats. The hopper bands fall into these trenches and they can be buried, preventing from entering the fields,” Cressman said.