Locust

Locusts are a group of grasshoppers that can switch from solitary to highly gregarious phases, forming large, migratory swarms. The term locust applies to populations of normally solitary species that exhibit phase polyphenism in response to crowding, rainfall, and food conditions. Locusts are not a distinct taxonomic unit; notable pest species include the desert locust (Schistocerca gregaria) and the migratory locust (Locusta migratoria), among others in the to genus Schistocerca. In the gregarious phase, insects show coordinated behavior, coloration changes, and increased mobility, enabling swarms to travel great distances.

Life cycle and development: Locusts undergo incomplete metamorphosis. After rain, females lay eggs in moist soil. Eggs hatch into wingless nymphs or hoppers that molt through several instars before becoming winged adults. Under crowded conditions, nymphs and adults form cohesive swarms that can persist for long periods and move with the wind.

Swarm behavior and impact: Swarms can contain billions of insects and travel hundreds of kilometers, consuming vast quantities of vegetation in a short time. They threaten crops, pastures, and wild flora, causing substantial economic losses and food insecurity in affected regions.

Management: Control emphasizes early detection and forecasting using rainfall and vegetation data, followed by suppression with insecticides or biological agents, and habitat management to reduce breeding sites. International cooperation, including guidance from organizations such as the FAO Desert Locust Information Service, coordinates monitoring and response efforts.