Life Cycle Of A Mosquito
The mosquito can be a fascinating insect when looking at its life stages. About 220 million years ago, a branch from the fly that we know today, decided he wanted to be different. Soon, he began developing the characteristics of the primitive mosquito.
During its evolution from a fly into a blood-feasting mosquito, the insect developed a long, slim body. The mouth grew in length, and sooner or later, its system became accustomed to hunting.
The life cycle of a mosquito spans over several stages. However, with over three thousand different species today, the development is unique for each one.
Some look for waterholes to hatch their eggs, while others seek out vegetation which may become flooded.
Understanding the mosquito’s development is essential when we want to reduce their numbers. That's why today, I will take you on a journey under the microscope, to take a closer look at the mosquito life cycle. From eggs to pupae, and through adulthood.
What Are the Mosquito Life Cycle Stages?
The life cycle of a mosquito measures over four vital stages—eggs, larvae, pupae, and adult. Through each of these stages, the mosquito grows from a microscopical dot to a full-grown bug.
Much like many other insects, a mosquito begins its life as an egg floating in the water.
When the female mosquito is ready to lay her eggs, she will find a spot generally in areas with still waters or aquatic vegetation. Through an opening at her bottom, she pops out her eggs.
Most female mosquitoes, initially those from the Culex and Culiseta genus, will lay their eggs together, as though forming a raft. This little floater will usually hover near the surface of the water. These rafts of eggs will hold around 200 each. Females adhering to the Anopheles, Ochlerotatus, and Aedes families choose to place their eggs separately.
Water is essential for the eggs' development. Some females choose to lay them in damp vegetation or soil. They're also able to spot the places which have the potential to become flooded and lay the eggs there.
Mosquitoes will choose places for their eggs away from potential predators. We generally see many mosquitoes around lakes or in larger water areas, however, this is not where they lay the eggs. Females will find waters where no fish will live. These places can include anywhere, from old tires left with water collecting inside, to a puddle.
When the eggs hatch, out emerge the larvae. The larva will wiggle and turn until the shell breaks, and it enters the world. It quickly makes its way to the surface of the water to take its first breath. Mosquito larvae can only live in water. Although they cannot breathe under the surface, they thrive in this environment.
The larva will generally stay near the bottom or behind hiding places. Now and again, it uses its body to wiggle up to the surface where it will use a tube to replenish its oxygen stores. However, some genera will instead attach themselves to vegetation and thereby establish a steady air supply.
When our little friend is hungry, it will feast on organic matter and other microorganisms it finds nearby. As the tummy grows, the larva will begin to molt. Much like a snake, when the skin becomes too tight, it will shed. This shedding will occur four times during the larval stage.
Finally, the last shedding takes place, and our little guy becomes a pupa.
During the closing of its childhood stages, the pupa will enter a non-feeding resting phase. During this period, it will concentrate on the last developments before emerging as an adult.
We can compare this stage to a butterfly, somewhat. Inside the small pupa cocoon, metamorphosis changes occur. Wings are formed, the tall, slender body and the long mouth used for feeding develops.
Although the pupa is in a supposed resting stage, it can be quite mobile. With the slightest change in light or rumble in the water, it will flip its tail and shoot towards the bottom.
At last, when the pupa stage draws to an end, it will emerge to the surface. Little by little, the adult mosquito will break the cocoon shell and enter the world above water.
Generally, the adult will take some time before it flies off. It is still wet from the cocoon and needs rest before venturing out.
The wings were folded, and its body was soft within the shell. Once out, the body will harden, so the mosquito can withstand the outdoor environment.
Our adult mosquito is on a tight schedule, as only a few days after emerging, it will need to begin feeding and mating with other mosquitoes. The cycle repeats.
What Do Mosquitoes Look Like Throughout the Stages?
Mosquitoes are oviparous, meaning the early stages of development take place outside the mother mosquito's body as opposed to within it, as mammals would.
Mosquito eggs are tiny. Only when many of them are glued together can they reach a size of about 1½ inches.
When the eggs first exit the female, they come out white and shiny. As they sink to the bottom of the water, their color changes over the course of a day, and they take on a brownish hue.
The rafts of eggs will look brown in color, almost as a speck, or as soot, floating in the water.
Larvae are long, slender wigglers. Their body consists of a head with eyes, a long abdomen and at the end, a tube called a siphon which they use to breathe.
The general color of mosquito larvae is brown. Along its body there are tiny bristles attached.
Two of the mosquito genera, Coquillettidia and Mansonia, are a bit different. Due to their modified siphon, these are able to attach to a stem of vegetation and thereby draw oxygen directly from the plant.
For the other species, they must come to the surface to breathe. The larva will hang with its head towards the bottom and the siphon through the surface. Here it will refill oxygen stores and then descend to the bottom.
There are other species who have their siphon located on their side. These larvae will float sideways near the surface to breathe.
While the larvae are near the surface, they will begin one of many feedings. Near their mouth, there are several tiny brushes which filter the food. The brushes sort and toss what the wiggler can and cannot eat.
Two specific species of mosquitoes, the Toxorhynchites, and some Psorophora are cannibalistic. Their larvae feed on other mosquito species' larvae and pupae.
These are much larger in size than their counterparts, so the other larvae make the perfect bite-sized snack.
Mosquito pupae look similar to a small shrimp. Many like to call these ‘tumblers,’ as they can tumble and jerk their way around the water.
A pupa consists of a large, round chamber where the head and wings of the mosquito develop. Attached to this room is a long tail-like case which holds the mosquito's long body. The color is still brown, and the bristles along the body remain.
The pupa has two breathing tubes, called trumpets, which pierce through the surface when it needs to breathe. Due to its light weight, it will spend most of its time hovering near the surface of the water.
The adult mosquito resembles a modified, or maybe even a premature butterfly. It has a fat, round upper body where its head is attached, followed by a long slim abdomen which expands when feeding.
It has four long, slender legs which by far outstretch the body in length. On the top of its head, there are two sensors. The mosquito uses these to find meals and potential mates. The sensors can feel temperature and odor changes.
A mosquito’s eyes can spot color differences which helps when looking for meals. Females are the only ones attracted to blood, which they require when producing eggs. Males, on the other hand, will only feed on nectar.
The mouth of a mosquito is what it uses to bite and feed with. The mouth works as a long tube which the mosquito will insert into a potential meal to suck out the nutrients.
Usually, mosquitoes are brown throughout their life stages. However, the Toxorhynchites species emerge from the pupa black, and along their legs, you can see white stripes. The adults, as well as larvae, are also larger and generally more aggressive.
How Do Mosquitoes Reproduce?
When it's time for business, the mosquitoes don't have much room for romance.
The males will form a massive swarm where the female mosquito enters. The sound of the female's wings are a bit different than the male's, so to locate the lady within the large swarm, the male will listen to the beat.
The two lovebirds will continue to swarm in the air. When ready, the male will grab onto the female with structures called claspers, located on the abdomen.
From here, the male can begin insemination by inserting his reproductive organ into the female mosquito. The deed is over rather quickly; it only takes about 15 seconds or less, depending on the species.
Now the impregnated female will venture out to find a blood meal to fill up on proteins for her eggs. When she's ready, she seeks out a place to lay the eggs.
How Many Eggs Do Mosquitoes Lay?
A female will lay around 100 to 200 eggs at a time. However, she can also store them inside her abdomen for when she finds a suitable location to lay them.
Interestingly, inside the male sperm is a chemical which entices the female to lay her eggs. Males can mate throughout their life, while females might only do it once and then simply store the eggs from that one partner.
How Long Do Mosquitoes Live?
The lifespan of a mosquito is not very long. Females tend to live longer than males; they can stay alive for up to 56 days. The male mosquito's primary job is to mate, so he will generally only survive about ten days.
However, mosquito eggs are a bit more robust. These tiny shells can, in fact, survive subzero temperatures during the winter and then hatch once the waters warm up again.
A mosquito's life is relatively short. Within that short lifespan, there's a ton of changes occurring each day. From the egg to larva, then from pupa into a grown adult, a mosquito’s metamorphosis is genuinely fascinating.
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