Chrysomya rufifacies is a species belonging to the blow fly family, Calliphoridae, and is most significant in the field of forensic entomology due to its use in establishing or altering post mortem intervals. The common name for the species is the hairy maggot blow fly, and it belongs to the genus Chrysomya, which is commonly referred to as the Old World screwworms. This genus includes other species such as Chrysomya putoria and Chrysomya bezziana, which are agents of myiasis. C. rufifacies prefers very warm weather and has a relatively short lifecycle. It is widely distributed geographically and prefers to colonize large carcasses over small ones. The species commonly has a greenish metallic appearance and is important medically, economically, and forensically.

Chrysomya bezziana, also known as the Old World screwworm fly or screwworm, is an obligate parasite of mammals. Obligate parasitic flies require a host to complete their development. Named to honor the Italian entomologist Mario Bezzi, this fly is widely distributed in Asia, tropical Africa, India, and Papua New Guinea. The adult can be identified as metallic green or blue with a yellow face and the larvae are smooth, lacking any obvious body processes except on the last segment.