A group of locusts is called as:

Swarm

The correct answer is swarm. A group of locusts is called a swarm. The word "swarm" is a collective noun, which means it refers to a group of animals of the same species. Other collective nouns for groups of locusts include:

• Plague: A large swarm of locusts that can cause widespread damage.
• Cloud: A large swarm of locusts that is visible from the air.
• Horde: A large and destructive swarm of locusts.