Locust Plagues India

      With a locust outbreak ravaging parts of western India, a Union Environment Ministry official said that it was a very badly-timed “serious infestation” that has occurred when the country is already in the middle of a pandemic.

      Even as India struggles to contain the COVID-19 pandemic and deal with the impact of Cyclone Amphan, another calamity is already knocking at its doors. North Indian states are facing a locust attack which threatens to damage standing crops and create a food shortage crisis.

            Standing crops and vegetables in Rajasthan, Punajb, Haryana and Madhya Pradesh face a major threat as swarms of locust have been reported a month in advance. There is an alert for Uttar Pradesh, Maharashtra and Delhi as well. State governments are scampering to control the swarms by providing farmers with pesticide sprays which can be mounted on tractors. The Rajasthan government is reportedly working on using drones and planes to spray pesticides.

            This is the second such attack in six months with Rajasthan already facing a similar outbreak towards the end of 2019. According to a report in Down To Earth, 60% of Rajasthan’s cumin crop worth Rs 300 crore was destroyed in the attack. Locusts are migratory pests which resemble grasshoppers but differ from them in their ability to form swarms and migrate great distances. There are 10 major species of locusts in the word with Desert locust (Schistocerca gregaria), Migratory locust (Locusta migratoria) Bombay Locust (Nomadacris succincta) and Tree locust (Anacridium sp.) being found in India.

India has not witnessed full-blown locust cycles since 1993. Heavy rains and an increasing number of cyclones, both are a result of the climate crisis, enabled unprecedented breeding and the rapid growth of locust populations on the Arabian Peninsula, last year.

§  Due to the 1926-1932 locust plague in India, the British government began research into the desert locust.

§  It then led to the establishment, in 1939, of a permanent Locust Warning Organization (LWO), with a station in Karachi (undivided India).

§  Its main job was to keep out an eye for a specific sub-species of the insect, the desert locust, that sprang into the region from the Thar desert.

§  After independence, India established its own centre at Jodhpur, Rajasthan, as a part of the Directorate of Plant Protection Quarantine and Storage, under the Ministry of Agriculture.

The high magnitude of insects attack and their early arrival highlights a critical aspect of global warming i.e. it may link disparate disasters — floods, pandemics and pestilence — amplifying the potency of each.

What are Locusts?.

Locust is an insect that belongs to species of grasshoppers. The desert locust is one of the species of short-horned grasshoppers in the family Acrididae that have a swarming phase. These insects are usually solitary, but under certain circumstances they become more abundant and change their behaviour and habits. As their population become dense, they form swarms and start damaging the crops.

A desert locust lives a total of about three to five months. This is variable and depends mostly on weather and ecological conditions. The life cycle of a desert locust comprises of three stages – egg, hopper, and adult. Eggs hatch in about two weeks (the range is 10-65 days), hoppers develop in five to six stages over a period of about 30-40 days, and adults mature in about three weeks to nine months but more frequently from two to four months.

A female desert locust lays eggs in an egg pod primarily in sandy soils at a depth of 10-15 centimeters below the surface. A solitary female lays about 95-158 eggs whereas a gregarious female lays usually lays less than 80 eggs in an egg pod. Females can lay at least three times in their lifetime usually at intervals of about 6-11 days. Up to 1,000 egg pods have been found in one square meter.

Desert locusts usually fly with the wind at a speed of about 16-19 km/h depending on the wind. Locust swarms can travel about 5-130 kilometers or more in a day. They can stay in their air for long periods of time. Example: (a) Locusts regularly cross the Red Sea, a distance of 300 kilometers. (b) Travelled from North-West Africa to the British Isles in 1954 (c) Travelled from West Africa to the Caribbean, a distance of 5000 km in about 10 days in 1988

A solitary desert locust usually flies at night whereas gregarious adults (swarms) fly during the day.

Locust swarms can vary from less than one square kilometre to several hundred square kilometers. There can be at least 40 million and sometimes as many as 80 million locust adults in each square kilometre of swarm.

A Desert Locust adult can consume roughly its own weight in fresh food per day, that is about two grams every day. A 1 km2 size swarm contains about 40 million locusts, which eat the same amount of food in one day as about 35,000 people. This is based on a person eating an average of 2.3 kg of food per day, according to the USDA.

A swarm the size of Niamey (Niger) or Bamako (Mali) eats the same amount of food in one day as half the respective country. A swarm the size of Paris eats the same amount of food in one day as half the population of France; the size of New York City eats in one day the same as everyone in New York and California; the size of Rome eats the same of everyone in Kenya; the size of Sydney (Australia) eats the same amount of food in one day as Australia eats in 1.5 hours.

Locusts do not attack people or animals. There is no evidence that suggests that locusts carry diseases that could harm humans.

People in several countries collect locusts using large nets and by other means. Locusts are usually stir-fried, roasted or boiled and eaten immediately or dried and eaten later (see some recipes below). Locusts are rich in protein. During periods of increased locust activity, piles of dead locusts can be found in the market places of many locust affected countries.

What caused the current Locust Attack?

Climate Change and Swarm of Locust

  • There are two meteorological drivers behind the current locust attack in India:
    • One, unseasonal heavy rainsin the main spring-breeding tracts in Arabian peninsula in March-April.
    • Two, strong westerly windsfrom the Arabian peninsula to India.
  • According to meteorologists, a differential pattern of warming in the Indian Ocean (Indian-ocean dipole)may be a trigger.
    • Last year saw one of the strongest positive dipoles in the Indian neighbourhood which brought on a difference of more than two degrees in temperature of the western and eastern Indian ocean.
    • Due to climate change, the anomalies in the Indian ocean dipole are increasing and subsequently, the monsoon pattern, intensity, cyclonic storms, are undergoing change.
    • The locust attack is just a manifestation of this change.
  • Due to this, in 2019, the monsoon started six weeks ahead of time in western India. It also lasted till November, instead of the usual September/October cycle.
    • The extended rains created breeding conditions and also produced natural vegetation on which locusts feed.
  • Further,cyclonic storms Mekunu and Luban struck Oman and Yemen respectively in the last year. Heavy rains had transformed uninhabited desert tracts into the large lake where the locust swarms breed.
  • Locusts are known to be passive flyers and generally follow the wind. Their movement has been aided by westerly winds,which further strengthened by the low-pressure area created by Cyclone Amphan in the Bay of Bengal.

Indian Ocean Dipole

  • 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.
  • negative dipole phase would bring about the opposite conditions – warmer water and greater precipitation in the eastern Indian Ocean, and cooler and drier conditions in the west.

What is the impact of Locust Attack?

  • Affecting Food Security:If their breeding is coterminous with that of the Kharif crop, then it could well have a detrimental effect on rice, maize and sorghum. Desert locusts eat leaves, shoots, flowers, fruit, seeds, stems and bark. All types of trees, crops and vegetation are feasted upon by the swarms greatly increasing the risk of food shortages.
    • The Food and Agriculture Organizationhas warned that the locust attack could lead to a major threat to food security.
  • Affecting Farmers:This means that locusts not only devour valuable standing crops but can also devastate livelihoods of farmers and those associated with the agricultural supply chain. Locusts swarms can fly up to 130 km in a day and each locust can eat around two grams of crop i.e. equivalent to its own weight. These swarms destroy crops and disrupt  agricultural economy in what is commonly referred to as locust plague.
  • Affecting Urban Areas:Due to the recent harvest of Rabi crops, there were no crops in the field, the desert locusts have been invading green spaces in urban areas
    • Though locusts are unlikely to be a major threat in urban centres, still they can disrupt day-to-day life.
    • Moreover, the effects of locust in urban areas may aggravate, as the national lockdown has made the availability and transportation of pesticide and labour difficult.

How to Control?.

There are generally three ways of controlling locusts — conventional pesticides, biopesticides and insect growth regulators. These pesticides are mainly sprayed through vehicle-mounted and aerial sprayers. In India, the Locust Warning Organisation under the Ministry of Agriculture, Co-operation & Farmers Welfare looks after controlling locust populations. Desert locusts typically follow a summer breeding cycle from July to October in India. However, the current locust swarms are originating from spring breeding areas in Iran, Balochistan and the Indus valley in Pakistan, according to a Ministry of Agriculture & Farmers’ Welfare bulletin.

  • Immediate Measure:A proactive control of locust attack through aerial spraying of the optimum quantity of insecticides in all potential breeding sites, is required, along with continuous monitoring of the crops during the ensuing Kharif season.
  • Need for Systemic Study on locust: Indian Council of Agricultural Research (ICAR)admitted that there hasn’t been much “systematic research” on desert locusts since the 1990s and the current invasion is a wake-up call to revive the programme.
  • Strengthening Research Framework for Climate Change:Due to the emergence of new dimensions of climate change, it is important that India puts in more funds to predict the course of the present global environmental changes to understand the sources, consequences, and formulate national responses.
  • Strengthening Decentralisation:There is a need to strengthen disaster management framework at the local level as highlighted by the Fourteenth Finance Commission report and Disaster Management Act, 2005.
  • Regional Cooperation:There is a need for collective regional efforts, as these locusts usually breed in the dry areas of Eastern Africa (especially Horn Of Africa) and the Arabian peninsula and enter finally to India.
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