The differences between grasshoppers and locusts are subtle differences. The difference occurs every fifteen or twenty years when the area where they live experiences heavy rain. The heavy rain causes millions of eggs to hatch. This changes the balance of their ecosystem. Scientists have learned that serotonin can change the grasshopper into a locust. Main differences occur in their lifestyle, size and color, where they live, and how far they travel to find food and mates.
Grasshoppers live in small groups in arid places. Locusts live is swarms of millions. They are very social as opposed to the grasshoppers that forage alone. Grasshoppers are shy and live for many years in the place close from where they hatched. Locusts hatch in huge numbers and travel great distances. Locusts can change themselves in regard to behavior, fertility, shape and color. Grasshoppers hop. Locusts can fly and hop.
Grasshoppers are smaller than locusts. They have drab, brown bodies with small wings. They have undeveloped leg muscles. Grasshoppers have longer antennae. Locusts are larger and have well-developed leg muscles and large wings. Locusts have a greenish color and very oily skin. Locusts are called short-horned grasshoppers.
Grasshoppers live in dry places where there is little water. Minimal amounts of grass and vegetation grow in these areas. Locusts live where there is abundant grass and vegetation. They often destroy farmers’ crops. Locusts are driven by the wind to other locations. They can survive at elevations exceeding 20,000 feet. They are ferocious eaters. A ton of locusts can consume the equivalent of ten elephants. Their diet includes leaves, grass, shrubs and crops. Grasshoppers are in the suborder Caelifera while locusts are in the family Acrididae.
Grasshoppers do not travel far from their birthplaces. Locusts are wind-driven and travel many miles from their birthplaces. They can block railways and highways causing dangerous conditions. They often get blown to the oceans and fall into the sea providing food for fish.
Malcolm Burrows, a Cambridge University zoology professor says, "These little guys changed from a shy creature that actively avoided making contact with other grasshoppers [into a creature] actively seeking out other insects and joining a gang.... Of the approximately 8,000 species of grasshoppers, only about 10 of them are likely to morph into swarming locusts.”
Burrows says that it takes days for locusts to switch out of swarm mode. The change rarely happens in the field, because those swarming were born that way. They do not know how to switch between modes.
Though locusts and grasshoppers share the same family Orthopera, they are different in their social interactions, their travels, their breeding, and lifestyle. Grasshoppers live in dry conditions but locusts need heavy rainfall to emerge. Grasshoppers and locusts are musical and make sounds with their legs or wings. Countries, where locusts have become a threat to crops, may benefit from the studies done concerning serotonin as it could curb the change the causes gentle grasshoppers to become ravenous locusts.