Blow flies are a diverse category of fly, although they are typically similar to house flies in both size and shape. Ranging from a quarter of an inch to half an inch in length, these flies can be metallic blue, black, or green in color depending on the species. The larvae of these flies feed on carrion and dung.
In general, each female blow fly deposits thousands of eggs over her 2 to 8-week lifespan. Egg masses can consist from 40 to over 1000 eggs. The eggs are laid on animal carcasses or in garbage or feces, any area with decay. Incubation of the eggs is around 4 days, but hatching can occur in less than 24 hours in warm and humid conditions. Once hatched, the larvae, known as maggots, will feed on the dead material around them. While they typically only feed on the dead matter, some species of blow fly larvae has been known to also damage and feed on living tissue. This is most common if the larvae encounters an open wound, however can also occur on unbroken skin.
While they typically don’t cause much damage, a large infestation of blow flies can be problematic. They are attracted to dead, decaying matter and usually are found near some type of carcass. When not feeding, blow flies can be found resting on walls in kitchens, bathrooms and basements. The easiest way to get rid of blow flies is to find and remove the dead organism they are feeding on. Once the carcass is removed getting rid of the flies can actually be relatively easy. They are attracted to light and will look for the quickest way out of your home. Something as simple as opening the patio door can help to eliminate the majority of the flies.
Did You Know?
Cluster flies are actually a type of blow fly! Read more about them on our Cluster Flies page!