Abnormal rainfall in the Arabian desert and an effect of the Yemen war have revived a menace that could hit Indian crops
This is from The Intersection column that appears every other Monday in Mint.
The butterfly effect occurs when a trivial cause, such as a butterfly fluttering its wings somewhere in an Amazon rainforest, triggers a series of events that end up having a massive impact elsewhere—a tornado ravaging the state of Texas in the US, for example. Edward Lorenz, the American meteorologist who coined the phrase in the early 1960s, came up with it while building a mathematical model to predict weather patterns. It is a fitting metaphor to explain a “plague” that is currently destroying vegetation and livelihoods in East Africa, the Arabian peninsula, Iran, Pakistan and India.
Even as the world’s primary attention has been fixed on the Covid-19 outbreak, which originated in China, several countries in Africa and Asia have been dealing with “the curse of good rains”: Massive swarms—called “plagues”—of the desert locust. Swarms as large as 2,400 sq. km, comprising 200 billion insects, have already damaged over 70,000 hectares of crops in Kenya and around 30,000 hectares in Ethiopia, according to the Food and Agriculture Organization. Last month, Pakistan declared a national emergency over locusts. In India, several districts in Gujarat and Rajasthan have been affected, and the latter has announced a compensation of ₹13,500 per hectare to affected farmers.
While locust swarms continue to plague African countries, for now, the outbreak has tapered down in India with swarms headed back towards Sindh and Balochistan. But that’s not end of the affair. The expectation is that the locusts will be back in June, by which time their numbers would have grown fivefold.
The brown-coloured desert locust usually lives as a solitary creature in desert and bush lands. However, when several of them gather in close proximity, they undergo a dramatic physical transformation, change colour to black and bright yellow, become gregarious, and start moving around in swarms. Locusts lay their eggs a few inches under the soil in the presence of moisture, which hatch faster under higher temperatures. Similarly, the flightless nymphs mature faster under warmer conditions and, within weeks, turn into adults that can form swarms of hundreds of millions of insects that can fly over 100km per day. Each locust can eat its own body weight—around 2-3 grams—every day, which means that a swarm can consume hundreds of tonnes of vegetation that it encounters every day.
Normally, desert locusts are limited to a recession area enveloping the African Sahel to the west and Rajasthan to the east. After international preventive control measures started in the 1940s, the intensity and spread of these swarms reduced, resulting only in regional plagues.
Over the past two years, though, abnormal weather conditions intersected with the region’s geopolitics to create the ongoing infestation. First, in 2018, two cyclones a few months apart delivered rain to the Rub al Khali, the remote desert called the “Empty Quarter” of the Arabian peninsula. The resulting ephemeral lakes created new breeding grounds for the desert locust in a poorly monitored region. Insecticide spraying operations were not conducted because of the war in Yemen. The breeding continued before the swarms crossed the Gulf into Iran and the Red Sea to Ethiopia and Somalia in the Horn of Africa. Here, too, conflict and political unrest limited control operations, leading to further breeding. Then, in December 2019, another cyclonic storm hit the Horn of Africa, creating conditions for yet more breeding. Today, the situation is dire in Somalia, Ethiopia and Kenya, and is worsening in Uganda and Tanzania.
Across the Persian Gulf, the Pakistani provinces of Balochistan and Sindh were initially affected, and when Punjab was hit, the government declared a national emergency and approached China for assistance. Across the border, several districts in Gujarat and Rajasthan were affected and neighbouring states, including Uttar Pradesh, are now on alert. Despite political tensions, Indian and Pakistani locust control officials met almost once a month over the second half of 2019 to exchange information, if not coordinate control efforts.
So far, India’s surveillance, preparedness and response have been competent and effective. The national Locust Warning Organization was set up in 1939 and is well connected to international institutions created to manage locust risks. It publishes weekly bulletins, and even has a Twitter handle. Bulletins show when locusts were detected, the location, extent and tonnage of insecticide sprayed and the risk of future infestation.
Climate change, with higher temperatures and changes in the Indian Ocean Dipole, could worsen the locust problem for India in coming years.
The immediate concern is that by June 2020, there will probably be extraordinarily large swarms in India, and that these could overwhelm the country’s current capacity to control them. The Union government is procuring additional spraying equipment and planning helicopter and drone-based control operations should the need arise. Containing the swarms at India’s border states is crucial, as India’s agricultural heartland lies just beyond.
China is largely protected against locust plagues by geographical barriers, but is relatively vulnerable in the Xinjiang region. Faced with a similar situation a couple of decades ago, the Chinese government had deployed hundreds of thousands of ducks that would eat the locusts in response to the blowing of a whistle.
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Reports in the Chinese media indicate that Beijing plans to do the same this year: Ducks will eat the locusts and, the Chinese, presumably, will eat the ducks. Since Islamabad asked for help, Beijing is reportedly planning to send 100,000 ducks to Pakistan, too. By the way, locusts are a delicacy in China and the Chinese might pass along some recipes to their Pakistani friends. It is unclear, though, whether Pakistanis will take a liking to it.
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