Life cycle The life cycle in sheep is typical of the disease. The female flies lay their eggs on the sheep in damp, protected areas of the body that are soaked with urine and feces, mainly the sheep's breech (buttocks). It takes approximately eight hours to a day for the eggs to hatch, depending on the conditions. Once hatched, the larvae then lacerate the skin with their mouthparts, causing open sores. Once the skin has been breached, the larvae then tunnel through the sores into the host's subcutaneous tissue, causing deep and irritating lesions highly subject to infection. After about the second day, bacterial infection is likely and, if left untreated, causes bacterial bloodstream infections or sepsis. This leads to anorexia and weakness and is generally fatal if untreated. Human vectors There are three main fly families causing economically important<unk>  in livestock and also, occasionally, in humans: * Calliphoridae (blowflies) * Some examples include Calliphora vomitoria and Calliphora vicina * Oestridae (botflies) * Sarcophagidae (fleshflies) Sarcophaga barbata are usually found in dead and rotting meat and animal excrement, which are prime environments for them. This is because their larvae are facultative parasites, as they feed on organic tissue and use the hosts' oxygen reserve. Other families occasionally involved are: * Anisopodidae * Piophilidae * Stratiomyidae * Syrphidae Specific<unk>  Caused by flies that need a host for larval development * Dermatobia hominis (human botfly) * Cordylobia anthropophaga (tumbu fly) * Oestrus ovis (sheep botfly) * Hypoderma spp. (cattle botflies or ox warbles) * Gasterophilus spp. (horse botfly) * Cochliomyia hominivorax (new world screwworm fly) * Chrysomya bezziana (old world screwworm fly) * Auchmeromyia senegalensis (Congo floor maggot) * Cuterebra spp. (rodent and rabbit botfly) Semispecific<unk>  Caused by flies that usually lay their eggs in decaying animal or vegetable matter, but that can develop in a host if open wounds or sores are present * Lucilia spp. (green-bottle fly) * Cochliomyia spp. (screw-worm fly) * Phormia spp. (black-bottle fly) * Calliphora spp. (blue-bottle fly) * Sarcophaga spp. (flesh fly or sarcophagids) Flesh flies, or sarcophagids, members of the family Sarcophagidae, can cause intestinal<unk>  in humans if the females lay their eggs on meat or fruit. Accidental<unk>  Also called pseudomyiasis. Caused by flies that have no preference or need to develop in a host but that will do so on rare occasions. Transmission occurs through accidental deposit of eggs on oral or genitourinary openings, or by swallowing eggs or larvae that are on food. The cheese fly (Piophila casei) sometimes causes<unk>  through intentional consumption of its maggots (which are contained in the traditional Sardinian delicacy casu marzu). Other flies that can accidentally cause<unk>  are: * Musca domestica (housefly) * Fannia spp. (latrine flies) * Eristalis tenax (rat-tailed maggots) * Muscina spp. The adult flies are not parasitic, but when they lay their eggs in open wounds and these hatch into their larval stage (also known as maggots or grubs), the larvae feed on live or necrotic tissue, causing<unk>  to develop. They may also be ingested or enter through other body apertures.
Myiasis
Trichiasis
Taeniasis
Trichuriasis
Acariasis
Ophiasis
Opisthorchiasis
Monorchism