What Are Blow Flies?

Blow flies are a common type of fly that you’ll likely see outside, where they find their preferred breeding grounds. These flies have a distinctive metallic appearance and loud buzzing sound. If you notice blow flies in great numbers in your home, it can be a sign of a much bigger problem. Learn more about blow flies so you’ll know how to address this issue.

Blow flies are a common type of fly in the United States, with about 80 species in this country alone. Worldwide, there are around 1,200 species of blow flies that you might encounter. These flies can be a nuisance in the home, but they are quite useful for other applications, as their appearance on a carcass or body provides a great deal of information to scientists.

What Do Blow Flies Look Like?

Blow flies are typically between 1/4 inch and 1/2 inch in length, making them a bit larger than house flies. They are metallic blue, black, purple, copper, or green. The blowfly has a wide head and compact body. Blow fly larvae are pale in color. The maggots look like small worms and are about the size of a grain of rice.

Where Do Blow Flies Live?

Blow flies are found in many areas throughout North America. They’re most common in the American southwest. Popular Science reports that rising temperatures are causing blow flies to migrate north, looking for more comfortable homes. One species typically found in southern states has moved north, making over two dozen documented appearances in Indiana over two years.

Blow flies typically seek out fresh carcasses. They will lay their eggs in these remains. The larvae remain on the carcass for five to 10 days, then leave to find a dry place to pupate. These maggots will then grow into adult flies in five to seven days. The newly grown adult blow flies will not lay eggs in the same carcass from which they were born, as it’s too dry by this time for reinfestation. You will often find these flies around garbage dumps, slaughterhouses, or meat processing plants.

Problems with Blow Flies

Blow flies don’t bite humans, but they do bring the risk of contamination. When they walk over surfaces, they can carry contaminants from other places they have landed. For blow flies, this is often on decaying creatures and fecal matter. They may spread microorganisms that can cause disease. Among the bacteria found on flies are salmonella, staphylococcus, and Enterobacter cloacae.

If you notice a large number of blow flies in your home, this can also be an indicator of a bigger problem. Since these flies are drawn to carcasses, a blow fly infestation often means that you have dead animals in or near your home. The presence of blow flies might alert you to another more serious problem, such as a rodent infestation. It’s ideal for you to determine where the blow flies are coming from.

Pest Control Solutions for Blow Flies

If you have a serious infestation of blow flies in the house, the first step is to identify the breeding source. As stated previously, blow flies are often an indicator of a nearby animal carcass that might be a more pressing concern. Eliminating the breeding area is the first step to getting rid of your blow fly problem.

If you’re having trouble identifying the source of your problem, a professional exterminator can help. A pest control professional will also verify the type of insect that you’re dealing with. Blow flies can be mistaken for house flies or bottle flies. A professional will help you confirm the insect that you’re dealing with.

Both fly traps and chemical applications can help with a serious blow fly infestation. These will help you eliminate existing flies that have taken up residence in the home. Such measures aren’t always necessary if you can get rid of the carcass that drew the blow flies to your home. A professional will help you assess the situation better.

Keep blow flies from returning by addressing any possible breeding grounds on your property. Keep garbage cans tightly sealed and clean them out regularly. Make sure your window screens are in good repair and seal tightly around the edges. Seal any gaps or cracks around windows or doors.

Other Blow Fly Information

Blow flies can be a pest in the home, but they’re not entirely bad. These flies can be beneficial in both investigative and medical applications.

Blow Fly Larvae Are Good Survivors

Blow fly larvae react to light by retreating into darker places. This is a handy survival instinct that helps them to hide from predators. Blow fly larvae secrete an enzyme that liquefies proteins in the carcass where they’re living, so they can easily digest this food source.

Blow Flies Help Investigators

Forensic scientists often use blow flies to determine the time of death for a body. The state of the larvae can let the investigator know how long the body has been in a particular area. However, it’s important for investigators to properly determine the species of blow fly that they’re working with. Recent blow fly migrations to different areas have made things more complicated for scientists who must be mindful of misidentifying a species and thus misestimating the time of death based on the wrong life cycle information.

Blow Flies May Have Medical Uses

Blow flies have been used for a technique known as maggot debridement therapy (MDT). The maggots will not eat healthy tissue, feeding only on decaying tissue. This can help individuals with wounds that are not healing properly. The maggots clean out unhealthy tissue, change the pH of the wound, and help to prevent bacterial growth.

If you have blow flies in your home, a pest control professional can help you decide how to best address this problem.