Migratory locust

Definition

A highly polyphagous grasshopper species capable of extreme density-dependent phase polyphenism, shifting between cryptic, sedentary solitarious forms and swarming, migratory gregarious forms that can travel hundreds of kilometers and devastate crops across continents. The type species of the genus Locusta and the most widespread locust species globally, occurring across Africa, Europe, Asia, Australia, and New Zealand with numerous described subspecies of debated validity.

Etymology

Latin migratorius (wandering, migrating) + locusta (grasshopper, locust)

Example

In 2020, gregarious bands of migratory locusts descended on East Africa after heavy rains, consuming vegetation equivalent to the food supply of 35 million people in a single day and prompting international control operations.

Synonyms

• Locusta migratoria

Related Terms

• gregarious phase
• solitarious phase
• phase polyphenism
• Desert locust
• African migratory locust
• locust swarm
• density-dependent phenotypic plasticity
• Schistocerca

Usage Notes

Not to be confused with the desert locust (Schistocerca gregaria), though both exhibit phase polyphenism and cause major agricultural damage. The migratory locust is distinguished by its more temperate distribution and taxonomic placement in Locusta rather than Schistocerca. Subspecies taxonomy remains contentious; some populations (e.g., in northern Australian savannas) appear to have lost swarming behavior entirely. The common name is sometimes applied loosely to any migrating locust, but properly refers only to Locusta migratoria.