When is a locust not a locust?
When is a locust not a locust? When it’s a Magicicada! Periodical cicadas like the 17 and 13 year Magicicadas, are often called 17-year Locusts, probably because they emerge in massive numbers. Cicadas are not locusts, in fact, true locusts are grasshoppers.
Take a look that the illustration of a true locust below. You’ll notice the true locusts have long rear legs for hopping, long antennae, and relatively long bodies. True locusts chew the plants they consume, while Magicicadas suck fluids from trees.
Locust:

17-year cicada:


