Thousands of locusts seen in a fresh attack in Sri Ganganagar district of Rajasthan

NEW DELHI/MUMBAI: India is buying drones and specialist equipment to monitor the movement of locusts and spray insecticides to ward off a new outbreak that could ravage crops, government officials said.

Earlier this year, Indian authorities were able to bring swarms of desert locusts under control, but an outbreak in neighbouring Pakistan has again raised concerns about the safety of crops such as wheat and oil seeds in India.

"Other than ensuring the availability of large quantities of insecticides, we're buying drones and sprayers to beef up our readiness to deal with the attack," one of the sources said.

Locust swarms can fly up to 150 km (90 miles) a day with the wind, and adult insects can consume roughly their own weight in fresh food per day. A small swarm eats as much in one day as about 35,000 people.

The plague has already caused extensive damage to pastures and crops and threatened food security in several countries over the Indian Ocean in east Africa, including Somalia, Ethiopia, Kenya Eritrea and Djibouti. Swarms have also spread into Tanzania, Uganda and now South Sudan.

Pakistan, which is facing the worst locust infestation in two decades, has declared a national emergency.

New Delhi is also sending civil servants to some of the most vulnerable areas in western and northern India to asses how prepared local authorities are to deal with any likely invasion of desert locusts, said the officials who cannot be named in line with government rules.

"We're also monitoring the situation in Pakistan," the first source said.

Indian and Pakistani authorities have met a number of times to review the overall situation, the sources said.

Asked if India would supply insecticides to Pakistan to help Islamabad deal with the locust outbreak, the first official said: "So far we haven't received any request from Pakistan."

India is already selling them to multiple countries.

"If Pakistan needs and our government allows, we can supply to Pakistan. We have manufacturing units in various countries. We can ramp up production of a particular insecticide depending on the demand," said an official from an Indian pesticide company, who declined to be named.

Islamabad could overlook a ban on trade with its arch-rival to import insecticides from India.

Villages in India's western states of Gujarat and Rajasthan states, which share a border with Pakistan's desert areas, are especially susceptible to the locust invasion.

The last major surge was in 1993, when heavy rains created favourable breeding conditions for locusts along the India-Pakistan border.