In pics: India calls in pest control as locusts attack states

At a time India is battling coronavirus pandemic, locusts present a new worry with huge swarms threatening crops. Swarms of locust were spotted a month ago and now they are in five states: Rajasthan, Punjab, Gujarat, Maharashtra and Madhya Pradesh. According to the Ministry of Environment, Forests and Climate Change, “Locust swarm from Pakistan has entered, threatening major damage to standing cotton crops and vegetables. Rajasthan is the most affected state. States are adopting various means for controlling the swarms.”

During the current year, the swarm of locusts has entered India earlier than their normal time of June and July. Lcusts are mostly as solitary insects or in small isolated groups. Their being spotted along the India-Pakistan border before mid-April this time — and coming after the damage they caused to the growing rabi crops along western Rajasthan and parts of northern Gujarat during December-January — has raised the alarm bells.

The national capital of Delhi was agog with rumours floating in social media about a swarm of locusts reaching the city and its adjoining area on 27th may. This, however, turned out to be a false alarm.

Locusts are the oldest migratory pests in the world. They are insects that belongs to the family of grasshoppers. Locusts are essentially harmless, however, when they meet suitable environmental conditions, they become start breeding. Locusts form enormous swarms that spread across regions, devouring crops and leaving serious agricultural damage in their wake.

When the locusts start attacking crops and thereby destroy the entire agricultural economy, it is referred to as locust plague/locust invasion. Plagues of locusts have devastated societies since the Pharaohs led ancient Egypt, and they still wreak havoc today. Over 60 countries are susceptible to swarms.

During dry spells, solitary locusts are forced together in the patchy areas of land with remaining vegetation. This sudden crowding makes locusts. Then, when rains return—producing moist soil and abundant green plants, locusts begin to reproduce rapidly and become even more crowded together. In these circumstances, they shift completely from their solitary lifestyle to a group lifestyle in what’s called the gregarious phase. Locusts can even change colour and body shape when they move into this phase. Their endurance increases and even their brains get larger.

Weather patterns and historical locust records help experts predict where swarms might form. Once identified, an area is sprayed with chemicals to kill locusts before they can gather.

There are four types of locusts that create a plague – desert locust, migratory locust, Bombay locust, and tree locust. The desert locust is a notorious species. Found in Africa, the Middle East, and Asia, this species inhabits an area of about six million square miles, or 30 countries, during a quiet period, according to National Geographic. During a plague, when large swarms descend upon a region, however, these locusts can spread out across some 60 countries and cover a fifth of Earth's land surface.