A swarm of locusts attacked Jaipur on Monday
NEW DELHI: A swarm of desert locusts which attacked Jaipur on Monday morning, could be headed towards the capital, if wind speed is favourable. Delhi has been kept on an alert, with swarms currently active in Rajasthan, Gujarat, Maharashtra, Uttar Pradesh and Madhya Pradesh. Rajasthan is currently the most affected state, according to the Union Environment Ministry.
Western Rajasthan and Gujarat are the normal places for desert locusts during the summer (from approximately June to November) but were first spotted by the Locust Warning Organization (LWO) in April this year. They are usually either solitary or in small groups, meaning the current swarming behaviour is unusual.
Entomologists said despite being an urban setting, the impact on Delhi could be severe, as it has a large green area as well – providing foraging material for the locusts. Delhi has around 22% of its area under green cover.
“There is a possibility that the locusts will move towards Delhi in the next few days if wind speeds and directions are favourable. As of today, the wind speed moved them towards north,” said the Union Agriculture Ministry’s LWO deputy director KL Gurjar on Monday.
The IMD has also been asked to monitor the meteorological conditions to help the agricultural ministry forecast where it may be headed next.
Kuldeep Srivastava, a scientist at IMD and head of the Regional Weather Forecasting Centre (RWFC) in Delhi, however, said wind direction was favourable at the moment, largely remaining north-westerly.
“In terms of the wind direction and to an extent even the speed, conditions right now are favourable and may allow them to move towards Delhi,” said Srivastava, stating the agricultural ministry will however be the one giving information on where it is actually headed.
Mohammad Faisal, an entomologist at the Yamuna Biodiversity Park (YBP) in Delhi, says the capital can suffer greatly, even if it has very little agricultural area. Faisal said the swarm, after surviving last winter in the desert, has moved out due to lack of food. Faisal says Jaipur, which was attacked recently has plenty of green spaces, including parks – providing foraging material for them.
“Delhi also has a lot of green area, including forests, ridge areas and parks which can be impacted severely. Even a very small, one square kilometre locust swarm can eat the same amount of food in a day as about 35,000 people,” said Faisal, who states in the past, they have been known to affect the water supply and railway lines.
“Railway tracks become slippery and need to be cleaned, after they attack. They have been known to clog wells too and therefore that is another area one may have to monitor,” said Faisal, stating this particular swarm may have been able to survive the winter – allowing them to thrive now and move ahead in search of food. “One single locust can lay up to 500 eggs. We need to tackle not just the swarm that is moving, but their breeding grounds as well, which is generally in the desert,” said Faisal, who specializes in the locust.
Sohail Madan from the Bombay Natural History Society in Delhi (BNHS) said the swarm may not only impact gardens and plants but other insects as well, which depend on the same plant profile for survival.
Abinash Mohanty, programme lead from the Council on Energy, Environment and Water (CEEW) however feels the current heatwave conditions could be a blessing in disguise, with locust numbers aided by rainfall and moisture.
“An increase in micro-temperature has triggered cyclonic disturbances resulting in more than 25 per cent excess rainfall during the early summer months of 2020. This excessive rainfall has favoured an early locust attack, thereby endangering the state of food security and disrupting the agricultural value chain. The current heatwave condition and delayed monsoon onset can be a blessing in disguise to control the locust breeding,” said Mohanty.
A typical swarm can be made up of 150 million locusts per square kilometre and is carried on the wind, up to 150km in one day, experts say.
Climate change-induced weather conditions – including more rainfall than normal is said to be aiding the locust swarm. Heavy rain triggers the growth of vegetation in arid areas where desert locusts can then grow and breed.
These locusts which migrated to India early this year might have found greener pastures as the pre-monsoon rains during March–May were in excess over north India this year.