Desert locust

The Desert locust (Schistocerca gregaria) is a prominent member of the order Orthoptera and the family Acrididae. It is widely considered one of the most destructive migratory pests in the world, capable of forming massive swarms that can devastate vast agricultural landscapes, crossing entire continents to feed on green vegetation.

The host range of the Desert locust is extremely broad, as it is a highly polyphagous insect. It feeds on almost all types of agricultural crops, including cereals (wheat, sorghum, millet, maize), pulses, vegetables, fruit trees, and various pasture grasses. In severe infestations, the sheer biomass of the swarms can strip entire fields of every edible leaf and stem in a matter of hours.

The biology of S. gregaria is defined by phase polyphenism. Depending on population density, individuals switch between the solitary phase and the gregarious phase. In the gregarious phase, morphological and behavioral changes occur: the insects become darker, more active, and start congregating into marching bands (nymphs) and flying swarms (adults), which are highly synchronized and mobile.

Damage is characterized by complete defoliation. Nymphs, while flightless, march through fields consuming seedlings and young crops. Once they reach the adult stage, they possess high flight capabilities, allowing them to migrate hundreds of kilometers daily. This leads to total crop failure, famine risks, and severe economic instability for the affected rural communities.

Effective control measures focus on preventive management rather than reactive spraying. This includes:

• Early detection of breeding sites via satellite mapping and field surveys.
• Targeted application of insecticides on nymph bands before they become winged adults.
• Deployment of biological control agents like Metarhizium acridum.
• International cooperation to share data and coordinate cross-border control operations.