Promachus is a large and robust insect belonging to the family Asilidae, commonly known as robber flies. They are known for their predatory behavior, preying on other insects in flight. Promachus species have a stout body, strong legs, and a distinct proboscis used for piercing and sucking fluids from their prey. They are characterized by their large compound eyes and a bristly appearance, making them formidable hunters in the insect world.