Locust Attack, Causes, Control and Climate Change


Vast hordes of locusts invaded the fields of Rajasthan and Gujarat devouring crops and destroying farmers’ livelihoods. There are little estimates on the scale of the devastation, but governments have sprayed pesticides over an area thrice the size of Delhi. Like the Australian fires, it can be argued that locust attacks are common in the region, so why the fuss? (Locust Attack)

What are Locusts

Desert locusts (Schistocerca gregaria) are short-horned grasshoppers with a highly migratory nature. They differ from grasshoppers in that they have the ability to change their behaviour and can migrate over large distances with the help of  winds. They live for 90 days and can eat food equivalent to their weight in a day.

They feed on green, leafy plants and always travel during the day time. Congregation of adult locust is called swarm while that of nymphal locusts is called band. An average locust swarm can have 8 million locusts and eats as much food in one day as 2,500 people or 10 elephants.

Locust breeding extends from the Red Sea coast to the Arabian Peninsula, Iran and Rajasthan. This insect grows exponentially. In the first breeding period, locusts increase by 20 times; in the second, by 400 times; and, in the third breeding period, by 16,000 times. This simply means that if there is an extended period of breeding, they will grow in extremely large numbers. It is difficult to track locusts because they move with the wind and there is no certainty where they will attack. (Locust Attack)

The first time Rajasthan woke up to the problem was in November 2019 when the agriculture department set up 54 teams to survey and monitor and deployed 450 tractor-mounted sprayers in affected dis- tricts.  lwcs  also  deployed  45 such vehicles. But swarms had already had three generations by then. Moreover, the government infra- structure was barely adequate.

The attack is also spreading to Punjab, Haryana and Uttar Pradesh. On January 12, the Uttar Pradesh government’s Sugarcane Commissionerate issued a press note warning about a locust threat to western Uttar Pradesh. But officials are still in denial mode.

It is about the globalization of insect infestations and pest attacks because of a changing weather.

What is Unusual about the Locust Attack?


This year, the swarms were much bigger and led to greater devastation. Why?

Its the first time that locust has stayed in India after October-November.This has happened for the first time since the 1950s. The decades before this witnessed terrible and long periods of locust plague (Locust Attack) (when there is a swarm attack for more than two continuous years, it is called plague).This time, they stayed for long. There is a change in the way locust invasions are happening, and this has to do with unseasonal rainfall, not just in India, but in the other breeding grounds of this insect.

Africa, too, witnessed one of its worst locust attacks last year.

It is linked to the attack in India and Pakistan. It started in mid-2018 when the desert region of Saudi Arabia received heavy rainfall due to a cyclone.There was another cyclone in November, followed by rains in the Red Sea coast region.These nine months of breeding produced an enormous number of locusts. Some of them moved north, to Iran, and from there came for spring breeding in India and Pakistan. Other swarms moved south, to Yemen, and in summer, crossed the sea to reach Somalia, to the Horn of Africa.

Reasons behind Locust Attack?

There are many linkages that need scrutiny.

There is a global link to India’s current locust problem. There are two permanent homes of the desert locust in India’s extended western neighborhood—around the Red Sea coast and along the Pakistan-Iran border. In May 2018, Cyclone Mekunu hit the Arabian peninsula (see ‘Global swarming’ on p20-21) and caused unusual spells of rain—a situation conducive to locust breeding. Parts of the arid Rub’ al-Khali desert (also known as “Empty Quarter”) developed lakes, a rare phenomenon that has not hap- pened in 20 years.

In October 2018, another cyclone, named Luban, hit the region, followed by heavy rains along the Red Sea coast in January-February 2019. The combined effect of these cyclones and rain was an extended humid condition resulting in an extended breeding season. Locust numbers rose so much that the region could not sustain the population and the insects started looking for new locales. Civil war-afflicted Yemen could not take preventive action, like it had in the previous attacks in 2007 and 2013, and locusts caused a famine-like situation in the country in 2019.

The cyclones also caused temporary shift in local wind pat- terns. Consequently locusts, which always move in the direction of the wind, went where the air currents took them. Batches of swarms crossed the Persian Gulf and the Red Sea to reach Iran and Africa respectively.From Iran they traveled to Pakistan around April 2019

Thus the causes were

First, it was the unseasonal rain in Pakistan’s Sindh province and western Rajasthan. This desert region of India is not the ideal breeding ground for locusts. The insect needs wet and green lands to proliferate. But last year, the region received rain ahead of schedule, which is why there was news about locust attacks as early as in May 2019. These were ignored.

Then the monsoon got extended—it did not retreat till October. Rains continued and the insect, which would have migrated back towards West Asia and Africa, stayed and bred.

Second, Cyclone Mekunu in May 2018 and then cyclone Luban in October 2018 brought extreme rain to the Arabian Peninsulacreating lakes in the desert, which are the ideal conditions for breeding.

Because of temperature change in the Indian Ocean, there are more cyclones.The frequency of cyclones has increased. Usually, there was a cyclone every five to six years, but in the past three years there have been three cyclones each year. Cyclones bring rain to coastal Gujarat, Pakistan, Arabian Peninsula, Somalia and north-eastern Africa.This creates good breeding conditions. History shows that these plagues spread due to cyclonic winds.

There was heavy rain in the Red Sea coast—also unseasonal—in January 2019. An extended rain period of nine months enabled the creature to multiply profusely.

Wind patterns are changing over India and Pakistan. With cyclones, wind patterns changed; locusts move with the winds. Normally, locusts come to India with the monsoon winds. In 2019, scientists say locusts crossed the Red Sea towards Africa and the Persian Gulf to reach Iran, which, is in any case, its winter resting place. From here, they made their way, in deadly swarms, to Pakistan and India.

When the locusts returned from Gujarat and Rajasthan to Pakistan-Iran in January/February 2020, there were already third-generation insects that had bred due to the extended monsoon in Rajasthan. That’s why, this year, the damage is much more.

What is being Done?

Scientists say LWC did not follow the standard operating procedure, as laid by the Food and Agriculture Organization (FAO), to detect locust infestation. As per the procedure, sandy areas where green vegetation is available and desert areas which have received recent rainfall must be regularly surveyed for live locusts or locust eggs. Areas that were attacked previously or where people have spotted locusts should also be watched. The procedure also says that areas where temperature from sunrise to mid-day stays between 20°C and 38°C should be surveyed because this is the optimum temperature range for locusts to breed. None of these guidelines were followed.

As a preventive measure now farmers are being encouragedto hire tractors, take free supply of insecticides and undertake spray operations themselves because government agencies cannot go everywhere in a short time.

Though LWC is the only body authorised to spray organophos- phate, the government has allowed farmers to use them. Organophosphates used by states to kill locusts are known to leech into water bodies and harm the ecosystem

Organophosphates,such as chlorpyrifos,malathion and fenitrothion,are a group of chemicals developed as human nerve agents by the Nazis and were later adapted as insecticides.These are known to leech into waterbodies close to agricultural fields. This varied exposure from different sources leads to bio accumulation in our bodies too.

The Food and Agriculture Organization recommends 10 types of chemicals (divided into three categories) to be used for controlling locust.

Of these,organophosphates are pesticides of the last resort.

The first category is of mycoinsecticides,such as metarhizium acridum.

These have low risk for non-target organisms,such as birds and reptiles which ingest the treated locusts.

The second priority category is Insect Growth Regulators,such as iflubenzuron,teflubenzuron and triflumuron.

These have very low human toxicityand are less hazardous in comparison to neurotoxic insecticides.They do have some adverse effects on certain non-target organisms,especially aquatic arthropods.

The first two categories would be effective if we have early locust infestations detection in place.But this time India acted late and ended up using these hazardous but effective organophosphates,”

Chlorpyrifos,kills 50 per cent of its targeted pest within three hours. The remaining get paralyzed or unconscious and die within the hour.

What can further done is to monitor the possible regions and spray pesticides if there is a known swarm resting at night. Locusts only fly and eat during the day. Since they lay eggs in moist soil at a depth of 10 cm, the areas where they were seen but have moved on must also be sprayed on as soon as possible.

In September and October (Locust Attack), Rajasthan asked the Centre to undertake aerial sprays to check locust attacks, but the government was advised government against the move because the people are no longer living in clusters, and have spread out, even living in fields,” Gujjar told dte. The spray could have harmed them.

Since swarms move across borders, they cannot be dealt with without international cooperation. For instance, before the Iran Revolution in 1979, Pakistan and Iran took joint actions against locusts in April , but the practice ended. It was revived in mid 1990s with the help of FAO, senior locust forecasting officer with FAO(Locust Attack). There should be a meeting between India and Pakistan every month to manage locust attacks.

But even after there is information, dealing with locusts is governments had failed in their duty, but farmers had saved the day by dealing with the raiders.

What happens next?

Can locusts return in May-June, or before the monsoon?

It does not matter if they go late or come early. Their children or great- grandchildren will come during the time of their annual migration, at the start of the monsoon. They move to south-west Pakistan, Baluchistan and south-east Iran where they hang out in the winter. They wait for rains as humidity and the resultant warmth creates a conducive environment for their breeding. If breeding is good, the new swarm formed in May-end could move back to India’s monsoonal areas around June. The difference this year was that south-east Iran received heavy rainfall in January (Locust Attack), giving an environment conducive for breeding. So, swarms are moving from India and Pakistan to lay eggs there. This generally happens in March-April, but this time it’s happening in January-February. This means Iran and Pakistan will now have an extra generation of locusts. This also means we will have 20 times more locust than normal.

The threat is not over yet. The swarms have started moving towards the Iran-Pakistan border. An unusual rain spell in south-east Iran in the first week of January, during which the country received a year’s worth of rain, has ensured that a treat awaits the locusts there. They will breed in Iran and if India has an early monsoon, they will return in larger numbers.

View our Blog:

For more details : Ensemble IAS Academy Call Us : +91 98115 06926, +91 7042036287

Email: [email protected] Visit us:-

#india #prime_minister #narendra_modi #government #locust #attack #LocustAttack #climatechange # #policy #blog #current_affairs #daily_updates #free #editorial #geographyoptional #upsc2020 #ias #k_siddharthasir #ensembleiasacademy