Myiasis is infection with the larval stage (maggots) of various flies. Flies in several genera may cause myiasis in humans. Chrysomya bezziana (Diptera: Calliphoridae) is the Old World screwworm and Cochliomyia hominovorax (Diptera: Calliphoridae) is the primary screwworm fly in the New World. Dermatobia hominis (Diptera: Oestridae) is the primary human bot fly. Cordylobia anthropophaga (Diptera: Calliphoridae) is known as the tumbu fly. Flies in the genera Cuterebra (Diptera: Oestridae), Oestrus (Diptera: Oestridae) and Wohlfahrtia (Diptera: Sarcophagidae) are parasites of other animals that also occasionally infect humans.