Read the following passage and answer the questions that follow.

Rajasthan’s farmers have been banging plates and lighting fires these days. It is their desperate attempt to scare away the swarms of migratory locusts invading their fields and eating away crops. The pest attack has come as a double blow for farmers already reeling under the impact of the Covid lockdown.

Millions of locusts, covering 1-4 sq km of the skyline, have reached 10 of the state’s 33 districts within three weeks of being first spotted on April 30. Last year, yellow locusts had entered India from Pakistan in the second half of May. The attack had originated from Yemen, coming all the way to West Asia and Pakistan and then India, creating havoc in 17 countries en route.

With the harvest nearly over in Rajasthan, the invading population of grasshoppers this May is feeding mainly on sprouting cotton crop sown last month, vegetables and fodder. State officials, though, fear damage to the young millet and moong dal crops due in July and August if the locusts breed.

Flying in through the Pakistan border near Jaisalmer, the locust swarms have infiltrated as deep as Kishangarh in Ajmer district. Locusts can cover 200-250 km in a day if they get wind support. Presently, the dust storms sweeping parts of Rajasthan are aiding their flight. Officials said the Union agriculture ministry’s Locusts Warning Organisation (LWO) is in the process of acquiring 60 vehicles with mounted insecticide sprayers from abroad by July. Ten such vehicles were purchased this January.

“Immature pink locusts are very active, which is why they have reached the interiors of Rajasthan [from Pakistan] so quickly,” says K.L. Gurjar, deputy director, LWO. Their metabolism slows down during winters, but in summers, they can fly from 4 am to 8 pm, covering long distances and consuming more crops along the way than mature locusts would. The LWO has put 10 insecticide-spraying vehicles on the job in Rajasthan. The Rajasthan government has provided rented tractors, on which insecticide sprayers are mounted, and also the manpower to man them. The Centre-state joint operation has so far cleared a few hundred sq km of fields of the locusts. Preliminary estimates put the loss to crops at a few crore rupees.

State officials say there is an urgent need to contain the pink locusts before they start breeding in the next few weeks. Indiscriminate aerial spraying of insecticides is ill-advised as this can damage crops as well as affect human settlements.

One of the strategies being considered now is to use fixed-wing aircraft for ultra-low volume spraying of chemicals. The state government may request for such aerial sorties by the air force. Drones have limited capabilities as they can carry only about 20 litres of insecticide at a time, making them effective only over small areas.