India - The ‘insect plague’ that’s eating crops
Several countries across multiple agro-climatic zones ranging from Africa, the Middle East to Asia are reeling under unprecedented locust attacks.
A warning — ‘Desert Locust Watch’ — put out by the UN’s Food and Agriculture Organisation (FAO) on 2 March has described the situation as extremely alarming, especially in Kenya, Ethiopia and Somalia.
While India has also suffered from the locust attacks, the country has for now brought the situation under control but only after substantial damage to crops in Rajasthan and Gujarat.
There are fears, though, that the situation may aggravate again with the onset of monsoon in June. Authorities are ensuring the availability of large quantities of insecticides along with drones and sprayers to upscale readiness for a possible attack.
India monitors locust swarms through its permanent locust warning and control system under the Indian Council of Agricultural Research. Set up in 1939, the system monitors the locust scenario in the desert regions of Rajasthan and Gujarat. Its field headquarters is in Jodhpur.
Apart from this, there is a Field Station Investigation on locusts situated in Bikaner.
Damage in India
India, along with Iran and Pakistan, falls in the Southwest Asia zone, which the UN’s FAO has identified as among the three flashpoints for locust swarms.
The other two include the Horn of Africa and the Red Sea zone.
Of the three, the Horn of Africa has been the most severely hit by locust swarm attacks to the extent that the FAO has described it as “an unprecedented threat to food security and livelihoods”.
Countries such as Ethiopia, Kenya and Somalia are among the 17 that have witnessed locust attacks in the Horn of Africa. In the Red Sea zone, locusts have devastated vegetation in Saudi Arabia, Oman, and Yemen.
In India, oilseed, cumin and wheat across nearly 1.7 lakh hectares of farmland have been affected by locust swarms, which came in from Pakistan through the border areas of Rajasthan and Gujarat.
Farmers in Rajasthan and Gujarat have been facing attacks from locust swarms since December 2019 after they entered from Pakistan through Jalore and Jaisalmer in Rajasthan, and then spread across Banaskantha, Patan and Mehsana districts of Gujarat.
88 per cent of the total 1,68,548 hectares of affected farmland have witnessed a severe crop loss of more than 33 per cent leading to damages in crores.
Rajasthan bore the brunt of the locust attacks — 1,49,821 hectares were damaged, of which 1,34,959 hectares sustained severe crop damage of over 33 per cent. In Gujarat, 18,727 hectares of farmland were affected.
The majority of the crops damaged are wheat followed by mustard, oilseed and cumin.
What are locusts
According to the UN’s FAO, locusts and grasshoppers are short-horned insects like crickets and long-horned grasshoppers. They breed in exponential numbers as they migrate long distances in destructive swarms, even from one continent to another.
In India, there are four species of locusts — desert locust, migratory locust, Bombay locust and the tree locust.
The insects not only causes immense damage to crops on farmland by ravaging leaves, flowers and fruits but they also destroy plants just by their weight as they come in massive numbers. Even a small swarm of locusts engulfing an area of one square kilometre devours food in a day that can feed as many as 40,000 people.
Locust ‘upsurge’
According to the FAO, desert locusts that are primarily responsible for an invasion across different agro-climatic zones and crop damage are present somewhere in the deserts between Mauritania and India.
If there is slightly above normal rainfall and green vegetation develops, the insects can rapidly increase in number in a month or two. An outbreak usually occurs within an area of about 5,000 sq. km (100 km by 50 km) in one part of a country.
If an outbreak or contemporaneous outbreaks are not controlled and if widespread or unusually heavy rains fall in adjacent areas, several successive seasons of breeding can occur, causing further hopper band and adult swarm formations — called an upsurge. This can affect an entire region.
If an upsurge is not controlled and ecological conditions remain favourable for breeding, locust populations continue to increase in number and size and can lead to a plague.
The last few upsurges lead to plagues. In India, the last major plague was in 1987-89 and the last major upsurge was in 2003-05.
The recent outbreak of locust attacks on Indian farmland occurred due to erratic rainfall in deserts of the Middle East in 2018, which created conditions conducive for locusts to breed.
Abundant rainwater gathered in different parts of the arid desert over Saudi Arabia, Oman, the United Arab Emirates and Yemen after the region was hit by Cyclone Mekunu in May 2018. It ended up creating favourable breeding conditions for desert locusts.
Locust swarms are known to retreat by November every year, but longer seasonal rainfall in India has created favourable breeding conditions for locusts in the Thar desert.
Tackling locust attacks
Though it’s almost impossible to exterminate a locust attack, the severity of it can be reduced by destroying egg masses laid by invading swarms.
This involves using insecticidal baits and spraying insecticides on both the swarms and their breeding grounds. However, large-scale invasions require equipment like large sprayer aircraft that are still not easily available in India.
Source - https://theprint.in
