Fly Life Cycle

Fly Life Cycle

Flies are one of the most widespread creatures around the world. They can be found anywhere, anytime, and sometimes they can even be very annoying. There are many different species of flies, including fruit flies, houseflies, horse flies, and many more. 

In this article, we will discuss flies’ lifespans and their development stages. Learning about the creatures that we encounter every day can be a fascinating thing to do. So, let’s start exploring. 

Briefly About Flies

Before discussing the fly life cycle, let’s first explore those insects briefly. Flies are one of the most common insects. In fact, approximately 125,000 species of those creatures fall in the order Diptera. The term “fly” is typically used when talking about flying insects. However, it is also used to describe the dipterans, which are “true flies.” 

The most common one among all is the housefly, scientifically known as Musca domestica. Houseflies have gray and black colors and come with large eyes.  

These insects perform several crucial ecological tasks while frequently having a negative relationship with people. Generally, flies are considered one of the most prevalent pollinators in the animal kingdom, and the first place there belongs to the bees

They aid in preventing the presence of animal carcasses in the environment. They also contribute to expanding the boundaries of human knowledge since flies are a frequent subject of genetic study.

What Do Flies Look Like? 

It is difficult to generalize the appearance of flies since they come in so many different sizes and forms. The dual-wing construction is the one element that all of them have. The second set of wings is largely utilized for balance and mobility. On the other hand, they actively use the first set of wings for flight. 

Two huge compound eyes, claws or pads that allow them to attach to smooth surfaces, and complex mouthparts are further noteworthy characteristics. The majority of the species in this group are smaller than one inch. Gauromydas heros, a fly native to South America, is the biggest species and may grow up to 3 inches long.

The body of the average fly is made up of three parts: the head, thorax, and abdomen. It is encased in a strong exoskeleton made of chitin, like all insects.

Those insects’ heads are covered by a pair of huge, complicated eyes. There are between 3,000 and 6,000 basic eyes in each eye. Houseflies’ eyes cannot focus on the specifics of their surroundings like those of vertebrates. Instead, they offer a fantastic mosaic picture of the things and environment around them. 

What Do Flies Eat?

These insects have developed a variety of feeding techniques. They can be parasitic, carnivorous, scavengers, herbivores, or even decomposers. Most of the species also have the ability to eat decaying matter like vegetables, meat, fruit, and feces.

 If other insects, such as tsetse flies and mosquitoes, consume the blood of vertebrates, some flies can eat the flesh itself. Flies will consume practically anything. They are drawn to organic things that are decomposing. They enjoy sweet things. 

Fly Life Cycle

The fly life cycle is pretty short and can only last for 15 to 30 days. During this period, those little insects go through different stages of development. The fly’s life cycle starts with the egg, then becomes a larva, pupae, and finally, after completing those stages, reaches adulthood. 

In summer, if the conditions for development are proper, the cycle from egg to adulthood can be as long as 10 days. Male flies chase and fertilize females; after that, the female is ready to deposit the eggs. So, let’s discuss the fly life cycle in detail. 

Egg Stage

The egg stage is the first step of the fly life cycle. Most species of flies are solitary insects. They do not stay together and do not care for the eggs laid. Once the female deposits the eggs, it leaves them and goes away. Typically, a female lays batches of eggs with amounts between 75 and 150.

The average number of eggs laid by mother flies in a lifetime is 500. However, one thing is that the mother chooses a protected location not to let predators harm the eggs. 

Flies like moist, warm places and lay their eggs in such locations. For example, the fly eggs are often seen on feces, garbage, food waste, carrion, and decaying matter. Eggs are white and typically have a length of 0.05 inches. The eggs can take somewhere between 8 to 20 hours before hatching.

Larvae Stage

The larvae stage is the second one of the fly life cycle. The fly larvae are also known as maggots. It looks like a worm and has a pale color. The larvae have sections with tube shapes and hooked mouths.

Maggots stay close to the food source to consume as much as possible and grow. Typically, they are found in manure, garbage, and animal corpses. As maggots eat and develop, they start the molting process.

Molting is when the insect sheds its skeleton as it grows in size. Once the skeleton underneath has fully developed, it sheds, and slowly a new one strengthens. Molting happens three times before the fly larvae move to the next stage of the fly life cycle. Maggots can grow quickly and even double in size in just two days.


After the fly goes through the final molting, it goes to the pupa stage of the fly life cycle. To prepare for this, the larvae go deep into the substance they have been feeding on. In the pupa stage, the skin becomes hard and gets a dark color. It becomes like a protective shell for the larva. 

Typically, in the pupa stage of the fly life cycle, the insect is dormant. It neither eats nor moves. The fly is like a cocoon and has a cocoon-like shell. There, the wings, legs, and antennas are grown and developed. After the body’s development, the fly emerges from the shell and is an adult. 

The newly emerged adult fly has a little bump on the head that used to come out of the cocoon. The fly does not have a jaw or teeth to chew out of the cocoon. There is when the fluid-filled pouch is needed to break out of the shell. When the fly reaches adulthood, the bump deflates and disappears.


The adult stage is the last step of the fly life cycle. Depending on the species, this stage can last a maximum of three months. Adults reproduce, and then the life cycle starts all over again. The average lifespan of the housefly is considered to be 21 days. 

Reproduction Of Flies

Flies typically survive for 15 to 20 days. Therefore, reproduction is crucial for them. They quickly begin to reproduce as soon as they reach the adult stage of the fly life cycle. The male fly initiates mating, which starts with courting.

The male fly fertilizes the eggs that the female fly creates. The whole mating procedure might take anywhere between 30 minutes and 2 hours. The female fly finds locations with the perfect conditions and enough “food” to feed the newly hatched flies.  

Where Can Flies Be Found? 

Flies like to stay near places where decomposing organic material is found. Such places are garbage, food waste, and manure. They enjoy warm weather and do well in temperature ranges of 17 to 32 °C. 

They may readily cause an infestation, given their pace of reproduction. Since flies are extremely unsanitary and may spread many diseases, this is a major issue, as we already mentioned above. 

How Flies Die

Houseflies may survive for 15 to 30 days. The average lifespan of a fly is 15 days for males and 25–30 days for females. Cooler weather causes it to take longer to develop and complete the fly life cycle. During the winter, they may hibernate.

If trapped inside a small, enclosed space, houseflies can also succumb to stress and die. They become lost and disoriented, and all these things increase the chances of death. Because of their inability to survive in air-conditioned environments, these insects may also die if this kind of circumstance occurs. 

Even though flies lead the world of insects that scavenge, several predators are just waiting for an opportunity to devour them. The threat includes wasps, spiders, frogs, lizards, and even some plant species that desire flies.

Additionally, people who are concerned about disease strive to keep out flies or kill them once they are inside. To avoid predators, flies have sensory awareness and quick mobility. 

Bottom Line – Fly Life Cycle

Above in this article, we discussed the fly life cycle. The most well-known type of fly is a housefly. They go through four phases in their life cycle: egg, larva, pupa, and adult fly. Fly lifespans range from 15 to 30 days and reproduce very fast. A single-fly female can lay over 500 eggs during her lifespan. 

Flies are regarded as pests because they often prefer to consume decaying organic items, breed quickly, and spread illnesses that are only found in food. However, they also have a significant role in the ecosystem and are among the most important pollinators.