All locusts are grasshoppers, but not all grasshoppers are locusts. Locusts are a special type of grasshopper capable of altering their shape, color and behavior in response to a change in density, an ability known as locust phase polyphenism.
In the lab, Dr. Hojun Song has created two density scenarios–high and low–for several species of grasshoppers he has caught locally in Florida, as well as another species from Texas, and still another he plans to obtain from California. He also is conducting field studies in Mexico and South America on other species, because he cannot bring the insects into the U.S. He and his fellow researchers already have generated data for two Florida species and have found that they do, in fact, have the ability to change, although they are non-swarming when found in nature.