The locust surge posing a threat to agriculture in India? How? Discuss with reasons.
India is gearing up for what could be one of its worst locust invasions in decades.
Outbreaks of the insect attack have been reported from Gujarat, Rajasthan, Maharashtra, Madhya Pradesh, Punjab, Haryana and Uttar Pradesh.
It could be worse this year because of a chain of climate events, administrative laxity in several countries and the difficult circumstances brought on by the COVID-19 pandemic.
Experts have warned of huge crop losses if the swarms are not stopped by June when the monsoons will lead to a new season of sowing rice, sugarcane, cotton and other crops.
In 2019, Gujarat and Rajasthan reported a significant surge in locust infestations. Nearly 3.5 lakh hectares of cumin, rapeseed and mustard were damaged and officials had then said that it was the worst attack since 1993.
This was partly due to an unusually long monsoon but also because pest-control operations were inadequate; therefore, nascent populations of the insect had not been wiped out.
A pattern of warming in the Indian Ocean may be a trigger for this attack. A phenomenon called the Indian Ocean Dipole, in which the western and eastern parts of the ocean, warm differentially, tend to have an outsized impact in bringing excessive rains to India and West Asia.
A ‘positive’ dipole is when the western part is hotter by a degree or more than the eastern. Last year saw one of the strongest positive dipoles in the Indian neighbourhood which brought on a difference of more than two degrees.
The Indian Ocean Dipole was so strong that it over-rode concerns of a drought in India last June and brought torrential rainfall — the most India has seen in decades. It also lasted nearly a month more than what is normal.
This extended rainfall continued in several parts of West Asia, Oman, Yemen and in the Horn of Africa — Ethiopia, Somalia, Kenya — so much so that that the dry sand became heavily moisture laden, facilitating the formation of several locust swarms.
It helped swarms to fly and breed in traditional grounds in Iran, Afghanistan, Pakistan and India.
The unusually mild summer this year, which saw several bouts of rainfall over north and western India from March to May, also helped the insects breed. The normal locust season in India spans June-November and coincides with the kharif season.
So far swarms have been recorded in nearly 50,000 hectares in Rajasthan and Madhya Pradesh and if they continue to thrive as the monsoon arrives, it could cause serious agricultural damage.
