General
Flesh flies, also referred to as blowflies, are larger than house flies (1 – 1.5 cm) and usually metallic blue or green. In the Netherlands, we have about 80 species. Very common are the flesh flies of the Calliphora family and the green or copper coloured emperor flies of the Lucilia family.
Lifestyle
Flesh flies prefer to lay their eggs on dead animals but also on dead meat in the kitchen, droppings or other rotting material. The females can recognize the scent miles away. The males however prefer flowers. Once the female fly has found a suitable food source, the lays hundreds of eggs on it.
After just 1 day, the larvae (maggots) crawl from the eggs. The maggots shun the light and crawl to dark places (under rugs, in cracks etc). After 6 to 12 days, the maggots are fully grown and leave the next to dig into the soil and pupate. After 8 to 13 days, the grown flesh flies emerge.
Damage
Flesh flies can spread pathogens such as viruses and bacteria and spoil meat and condiments due to contamination (eggs, droppings.
Use
In nature, the flesh flies serve as a cleaning crew for waste and cadavers and serve as food for other animals.
Prevention
Keep windows and doors closed when possible or fit them with insect screens.
Keep meat and condiments cool and covered
Remove waste in a timely manner
Keep tables, floors, walls, machines etc clean
Dispose of dead animals
Control
Track down breeding places; dispose of dead animals. meat waste etc and properly clean the places where the maggots are developing. If necessary have the breeding places treated with an insecticide based on deltamethrin, permethrin of cyfluthrin.