Huge swarms of desert locusts are destroying crops across western and central India, prompting authorities to step up their response to the country’s worst plague in nearly three decades.

Drones, tractors and cars have been sent out to track the voracious pests and spray them with pesticides. The locusts have already destroyed more than 50,000ha of cropland.

“Eight to 10 swarms, each measuring around a square kilometre are active in parts of Rajasthan and Madhya Pradesh,” the government’s Locust Warning Organisation’s deputy director KL Gurjar told AFP.

The insects caused massive damage to seasonal crops in both states, devastating many farmers already struggling with the impact of a strict coronavirus lockdown.

They destroyed harvests in the agricultural heartlands of neighbouring Pakistan last month, before entering Rajasthan.

Smaller swarms are also active in a handful of states across India, said Gurjar.

A swarm of 40 million locusts can eat as much food as 35,000 people – or six elephants – said UN Food and Agriculture Organisation.

Residential areas in the state capital Jaipur were overwhelmed by the insects as bewildered locals banged on pots and pans to try and ward off the insects.

Experts warn the situation could worsen with more expected to reach India via Pakistan from the Horn of Africa next month.

Heavy rains and cyclones enabled unprecedented breeding and the rapid growth of locust populations on the Arabian peninsula early last year, said the UN.

India has not seen locust swarms on this scale since 1993 when it experienced a widespread plague, the warning centre said.

Locusts destroy crops in some parts of Rajasthan close to the border with Pakistan most years, but it is rare for the insects to move further into the state.

Wind patterns have been pushing the swarms southwest, the locust warning centre said.