The Locust Swarm: A Growing Threat to Agriculture

Locust swarms have long been a threat to agriculture, but their impact is becoming more severe due to climate change and globalisation. The UN Food and Agriculture Organisation (FAO) warns that locust swarms can cause widespread damage to crops and pastures, leading to food insecurity and economic losses. According to the FAO, a swarm of one square kilometre can contain up to 80 million locusts, which can eat the same amount of food as 35,000 people in a day.

Locusts are not picky eaters and can feed on a wide range of crops, including cereals, fruits, vegetables, and fodder. This makes them a threat to food production, as well as livestock grazing. Locust swarms can also damage infrastructure, such as irrigation systems and roads, and affect human health by causing respiratory problems due to the dust they generate. The increasing frequency and intensity of locust outbreaks pose a significant challenge to agriculture and food security, particularly in countries with low-income, fragile economies, and weak institutional capacity.

The Anatomy of a Locust Swarm

Locust swarms are a phenomenon of gregarisation, which means that normally solitary insects gather into dense and highly mobile groups called swarms. The transformation from solitary to gregarious behaviour is triggered by specific environmental conditions, such as abundant vegetation, high humidity, and warm temperatures. When these conditions persist for a few months, locusts start to change their physical appearance and behaviour. They become more active, aggressive, and voracious, and develop wings that allow them to fly long distances in search of food and breeding sites.

Locust swarms consist of different stages of development, from hoppers (wingless nymphs) to adults, and can last for weeks or even months, depending on the availability of food and the weather. Swarms can cover vast areas, from a few square kilometres to hundreds of square kilometres, and move at speeds of up to 150 km/h. They can also change direction quickly and unpredictably, making them difficult to track and control. Locusts are highly adaptable to different environments, and their ability to reproduce rapidly can lead to explosive population growth if left unchecked.