Machimus floridensis is a species of predatory robber fly found in Florida, United States. It is characterized by its large size, reaching up to 1.5 inches in length, and its distinctive black and yellow coloration. This species is known for its impressive hunting abilities, preying on a variety of insects including flies, bees, and grasshoppers. Machimus floridensis is an important predator in its ecosystem, helping to control populations of pest insects.