What Is the Lifespan of a Fly?

What Is the Lifespan of a Fly?

When you see flying insects in your home, the last thing you want is for them to stay a while. How long the pest affects you, though, will depend on what kind it is and how many eggs have been laid, among other factors. 

There are several common flies that may make your home their own, such as the housefly, fruit fly, mosquito, and gnat. Here’s what you need to know about these pests’ life cycles and what to do if you run into an infestation indoors.


The average housefly (Musca domestica) lives 28–30 days once it reaches adulthood. Its total lifespan is around a month and a half from egg to death. 

The stages of a housefly’s life cycle include:

  1. The egg stage, which lasts 12–24 hours.
  2. The larval stage, which lasts 4–7 days.
  3. The pupal stage, which lasts 4–6 days.
  4. The adult stage, which lasts 28–30 days.

Houseflies can lay up to 150 eggs at a time, so the life cycle is constantly in motion—that means you’ll see new flies emerging as adults all the time, even as some die off. Addressing the places where flies breed and lay eggs, like open organic material in the home, is necessary to eliminate an infestation.


Fruit flies (Drosophila simulans) are small flies that you might find flying around your counters near fruit or vegetables. They can reproduce rapidly, so it’s not odd to see dozens of them at a time when you’re facing an infestation.

Fruit flies live up to 50 days as adults and go through their first three stages—the egg, larval, and pupal stages—in as quickly as a week.


Fruit Fly Genetics: Did you know that fruit flies can have either white or red eyes? White-eyed fruit flies have recessive genes that give them white eyes, which is why they’re often used in science experiments to explain dominant and recessive genes. 

If two white-eyed fruit flies mate, you may find that your fruit flies have either red or white eyes. For example, if a red-eyed male fruit fly mates with a white-eyed female, then the sons will have white eyes, and the daughters will have red eyes. 



Mosquitoes (family Culicidae) are annoying pests known for inflicting itchy bites. They start as eggs that hatch while submerged in water. Then, they become larvae and may develop into pupae in around 5 days. From that point, the pupae develop into adults in around 3 days.

Once an adult, male mosquitoes live around 1–2 weeks. Females, on the other hand, are much hardier. They live up to several months, especially in seasons during which predators have migrated away. 


Gnats (order Diptera) are tiny flying insects that live around 28 days in total. The average adult lives only 1 week. 

The gnat life cycle has four stages, like other kinds of flies. They start as eggs, move on to larvae, become pupae, and then grow into adults. 

If you notice gnats in your home, look around the area where you see most of them. That may be the breeding ground, helping you identify the infestation so you can more easily get rid of it. Gnats continuously breed, so while it may seem like they “just don’t go away,” the reality is that there are always new generations hatching and making your house their home.


Whether you’re dealing with mosquitoes or some other flying pest that you can’t seem to get rid of, we’re here to help. We know insects can be annoying, which is why we have a number of options to help your household say goodbye to flies. Give us a call today at Joshua’s Pest Control to speak with an expert about a free quote. 


Author Bio

Courtney Enzor has worked in the pest control industry for about a decade. From helping you build a fly trap to giving you the best tips for identifying various bugs, she loves answering all your pest-related questions and sharing her pest-related expertise through writing. At the end of the day, she hopes her content will help people avoid mishaps and keep families happy and healthy!