Family Sarcophagidae (Flesh Flies) is represented by more than 2600 species. Most are parasitic on arthropods and mollusks, some on vertebrates. A small number of species have true preference for vertebrate carrion and excrement. They are large, non-metallic flies, about 10-15 mm long, grayish in color with 3 prominent black longitudinal stripes on the thorax.
Adult Sarcophaga do not lay eggs. Eggs develop within the female's body and she deposits larvae directly on a potential larval food source. Larvae are deposited in batches of 40-60, on decaying carcasses, rotting food and human and animal excreta, but sometimes in wounds. Larval development lasts only 3-4 days, after which the larvae bury in soil and pupate, and the puparial stage lasts about 7-10 days.1 Their habitats make them public health suspects. They were reported to transmit some viruses, such as poliovirus, bacteria, such as Salmonella and Shigella, and protozoan cysts and helminth eggs, such as Entamoeba histolytica, Giardia lamblia, Hymenolepis nana, Trichuris trichiura, and Ascaris lumbricoides.
Red-eyed flesh-fly (Sarcophaga aldrichi) is distinguished by red eyes. Larvae feed on insects, and they are common predators of pupae of tent caterpillar. Sarcophaga crassipalpis has a black and white checkered pattern on the abdomen. The tip of the abdomen is orange-brown. Full-grown larvae are 20-22 mm long. Larvae infest ham and other prepared meats. It has been found in wounds and bedsores.2
Sarcophaga species produce myiasis (from Greek mya, or fly), the parasitic infestation of the body of a live mammal by fly larvae (maggots) that grow inside the host while feeding on its tissue. This disease occurs predominantly in rural areas, and is associated with poor hygienic practices and low standards of living. Several forms of myiasis are recognized: bloodsucking, cutaneous, furuncular and migratory, wound myiasis, cavitary, cerebral aural, nasal, and ophthalmomyiasis. Cutaneous myiasis, together with wound myiasis, is the most frequently encountered clinical form. Furuncular and migratory forms are included in this group. Sarcophaga species have been reported to cause aural, intestinal, and nosocomial (one that occurs in hospital settings) myiasis.4
Most cases of myiasis in pets appear to be the result of an untended wound or matted hair, and the presence of excrement, which indicates that owner neglect has a major role in the occurrence of myiasis. In many cases, this is probably the result of ignorance rather than deliberate neglect or abuse, and owner education may go a long way to alleviating the problem.5
- Medical Entomology for Students. Mike Service
- Urban Insects and Arachnids: A Handbook of Urban Entomology. William H. Robinson
- Gastrointestinal Myiasis by Larvae of Sarcophaga sp. and Oestrus sp. in Egypt: Report of Cases, and Endoscopical and Morphological Studies
- Myiasis in pet animals in British Columbia: The potential of forensic entomology for determining duration of possible neglect