The term is used differently in different places. Sometimes, it refers to smaller grasshoppers. In North America, the words locust and grasshopper are often used interchangeably, with locust less commonly applied to cicadas.

I give you now Professor Twist,
A conscientious scientist,
Trustees exclaimed, "He never bungles!"
And sent him off to distant jungles.
Camped on a tropic riverside,
One day he missed his loving bride.
She had, the guide informed him later,
Been eaten by an alligator.
Professor Twist could not but smile.
"You mean," he said, "a crocodile."

~Ogden Nash