What is the Lifespan of a Mosquito

What is the life expectancy of a mosquito?

The life of mosquitoes varies with the sex – male mosquitoes have generally a very shorter life span, while female mosquitoes have a longer lifespan. The shorter lifespan of male mosquitoes from 1 to 2 weeks, signifies that they have nothing to do much which is important, other than mating. While the female mosquitoes can live upto a month or even upto 50 days and this is because they have a major role to play that is reproduction.

Because of their reproduction, we face many troubles, health risks and diseases, and lifestyle concerns. This also depends on the external environmental factors like temperatures, weather and humidity levels. The female mosquitoes need intense energy and nutrition to produce eggs, for which they find hosts for blood meals.

It is important to clarify at this point, that only female mosquitoes bite as they need bloodmeals to reproduce, while male mosquitoes mainly feed on plant juices and nectar.

Mosquito lifecycle will help you in understanding the factors that either promote or suppress the survival of mosquitoes. We should develop effective strategies and methods to control their population unless we are not concerned about the ill effects of mosquito related diseases and viruses.

Mosquito lifecycle overview

The lifecycle of mosquitoes, where they undergo transformation in 4 stages mainly aquatic phases. This complete metamorphosis, takes place in 4 distinct stages – egg, larva, pupa and adult. Each stage is different and has its own significance. They have different form and function but poses no health risks and dangers at these development stages.

Only the adult form of mosquitoes poses great risk and threat to humans as they are the carriers of many fatal and deadly diseases – Malaria, dengue fever, Zika virus, Chikungunya, West Nile virus, etc.

The time and duration of each stage varies and they undergo 4 instar molting processes at larval stage. The rate of growth and development depends on many external factors

1. Egg Stage: The life of a mosquito starts from an egg. The female mosquito lays eggs in or near water, typically around 300 eggs, either individually or in clusters. The location of water body and its type, whether its a pond, or water tank, or a seepage/ leakage, puddles, marsh, etc. decides the survival of these eggs.

There are few species, where eggs hatch within few days. But there are certain species which are found in temperate regions where they remain dormant for months (state of hibernation) and once the favorable conditions like temperature and humidity are met, they start hatching.

2. Larva Stage: Once the eggs hatch, they enters into a larva stage. These larvae have a long, segmented body that is tapered at the end. These are called as wrigglers because of their characteristic movement and behavior in water. They moves side to side and hang upward down with their tail outwards in the air from the surface of water.

They feed on decomposing organic matter and algae. This stage lasts for 4 to 14 days depending on their growth rate. This rate of growth depends on availability of stagnant water, sufficient moisture, temperature and food. The larvae undergoes 4 instar molting processes – larva 1, larva 2, larva 3, larva 4. After each molt they grew bigger and bigger in size with no difference in appearance.

3. Pupa Stage: After the final molt, the larva turns into a pupa. In this stage, the pupa don’t feed they are enclosed in a casing, where they actually are in resting and transformation period. At this stage they are preparing to become an adult. This pupa stage typically lasts for 1 to 4 days.

4. Adult Stage: At this stage, the final fully developed insect emerges out of the pupal casing. Once their wings are dried and hardened, they fly away from water in search of food. The female mosquitoes depends on blood meals from humans while male mosquitoes rely solely on nectar and plant based sugars for food. This is the beginning of mosquito’s interaction with their surrounding, where they are responsible for:
– Mosquito bites, and
– Transmission of diseases

Average lifespan of a mosquito (Male and Female)

The life span of an adult mosquito depends on many factors – species, sex (male or female), temperature, humidity, access to food, etc. which has been distinguished in detail below:

1. Male mosquitoes: Male mosquitoes don’t depends on bloodmeals. They feed only on plant juices, sap and nectar from flowers. Their main purpose is mating and allowing female mosquitoes to reproduce. After mating season, once they are done with their reproductive role, they soon die. The lifespan of male mosquitoes last for 1 to 2 weeks.

2. Female mosquitoes: They need blood meals to get energy for developing and laying eggs. They are potentially more active in seeking hosts for blood, and thus live longer than males. After mating, they lay multiple batches of eggs and have multiple blood meals, during their lifetime. Thus, they typically lives around 30 days or even more under favorable conditions.

Factors affecting lifespan of mosquitoes

The two internal factors, mainly sex and species, are also responsible for their different lifespan. But since we are learning the factors that surprisingly change the lifespan of mosquitoes, we will consider the external factors. The following are the major external factors that affect the lifespan of a mosquito.

1. Temperature

Mosquitoes are cold blooded insects, it means that their body can’t generate heat. And so their body temperature and growth process completely depends on surrounding’s temperature. Higher temperature can accelerate their development process and thus ultimately their lifespan gets shortened. While cooler temperatures can slow down their metabolic processes and increase their lifespan.

At optimal temperatures (25^o C to 27^o C or 77^o F to 81^o F) female mosquitoes can live up to a month. But at warmer temperatures (above 30^o C or 86^o F), their lifespan decreases significantly. This is due to their accelerated growth process.

2. Humidity

Humidity is very much required for their growth and survival. Higher moisture levels in the surrounding reduces the loss of water through evaporation and keeps them hydrated. In dry and arid regions, mosquitoes lifespan is shorter as they can’t rehydrate and die due to dehydration.

3. Stagnant Water

Still water is very much important for laying eggs. But if there is agitation or motion within water body than the eggs can’t survive. After mating, female mosquitoes must lay eggs and if they don’t get water they will die soon. Even after getting water as required for their survival, the mosquito density decides their lifespan as there may be limited resources like organic matter to feed larvae. And many larvae may don’t survive due to lack of food in water.

4. Predators

Natural mosquito predators like mosquitofish, goldfish, purple martin, bluebirds, wrens, dragonflies, spiders, bats, etc. eat mosquitoes and their larvae. these predators specially the mosquitofish are the most effective in controlling mosquito populations.

Many mosquito control programs and strategies make use of certain predators to control mosquitoes population. In environments and surroundings where these predators are large in population, the mosquitoes may have a shorter lifespan.

5. Availability of food

Female mosquitoes needs blood meals to support the developing eggs, while the male mosquitoes as well as female ones can survive on nectar and plant sources, but this will affect their lifespan differently. As female mosquitoes needs blood to reproduce and if they fail to get blood, they will end up consuming feeding on nectar which will give them a shorter lifespan as those of male mosquitoes.

6. Mosquito control measures by humans

Humans take number of actions to get rid of mosquitoes. Many activities involves use of mosquito nets, mosquito traps, use of insecticides, use of mosquito repellents, etc. Such similar activities can drastically affect the lifespan of mosquitoes, by restricting them away from food sources, by starving them or killing them.

Using chlorine or certain larvicides, in water bodies can kill the eggs and larvae, thus reducing their population. While using insecticidal spray in surrounding can reduce the adult mosquito population in that region thereby considerably affecting their lifespan.

After mating, female mosquitoes seeks hosts for blood meals to nourish their developing eggs. This process of finding hosts and biting them for blood meals, exposes them to various risks and so they endanger their lives in order to lay eggs. They are most likely killed or repelled by these repellents and traps. The most successful female mosquitoes obtain blood meal and lay their eggs and live longer.

Common mosquito species and their life span variations

The 3 common mosquito species that spreads or transmits major vector borne diseases in humans, are:

1. Aedes mosquitoes

The Aedes mosquitoes typically have a lifespan of around 2 to 3 weeks. They are mainly found in tropical and sub tropical regions where temperature throughout the year remains warm. These are even active at daytime, and bites aggressively. These Aedes mosquitoes are responsible for spreading many dreadful diseases like chikungunya, dengue, zika, and yellow fever.

2. Anopheles mosquitoes

The lifespan of anopheles mosquito is generally around 2 weeks. But as the temperature goes down or cools down, their lifespan may increase to some extent. These are crepuscular in nature. As they are active from evening to sunset. This anopheles mosquito is responsible for transmitting malaria, the most viral mosquito disease all over the world. they are the primary vectors for malaria.

3. Culex mosquitoes

The lifespan of culex mosquitoes can go from 2 weeks to 1 month. They are mainly found in colder temperate regions and are most active in night. This culex mosquitoes are responsible for diseases like West Nile virus, Lymphatic filiariasis, and Japanese encephalitis.

Impact of mosquito lifespan on transmission of diseases

The ability of a mosquito to transmit diseases is directly related to its lifespan. The longer the mosquito lives, it will get more time to bite multiple hosts and spread infections and viruses. But there are certain diseases that need an incubation period within the mosquito, before they are ready to transmit to other hosts.

1. Incubation Period

Many mosquito borne-diseases like Malaria, Dengue and Zika require an incubation period within the mosquito. After biting the infected host, the mosquito develops pathogens inside their body, this is required; than only the mosquito can transmit disease on next bite to another non-infected host. this incubation period can vary from few days to over a week, depending on the disease and environmental conditions.

If the mosquito may not able to survive or dies due to any reason, maybe due to starvation or due to human interventions like insecticides, traps, nets, natural repellents, smoke fire pits, etc. Because of which mosquito bearing the disease pathogens dies off before it bites and transmits the disease.

So, if the mosquito does not lives long enough to complete the incubation period, it may not be able to transmit the disease. On the other hand, if the incubation period is very small, than it will get sufficient time for more bites and transmit disease at a higher rate.

2. Multiple opportunities to bite

If the mosquito gets an opportunity to bite multiple times it will transmit diseases to higher number of hosts. If there is not much biting opportunity like consistent use of repellents, using mosquito nets and traps that keep mosquitoes away, burning coffee grounds, use of firepits, citronella candles, using Pine Sol at homes, Camphor mosquito repellent, etc.

Any of these attempts can keep mosquitoes away for a considerable time and thus humans can escape mosquito bites. And so the number of biting events remains lower, as a result the rate of transmission of diseases is very slow.

3. Disease control interventions

As we know that incubation period and opportunity for multiple bites, both can directly affects the rate of transmission of diseases. Now, if stringent control measures and effective mosquito control programs from public health departments are followed than their population will be reduced to larger extent. As a result their lifespan will be very much shorter, and so their ability to transfer the disease can be reduced to a minimum.

Conclusion

The lifespan of mosquitoes is dependent on many factors like sex, species, environmental conditions, availability of food, predators, etc. The typical lifespan is given just for an idea, but their actual lifespan is dependent on many external factors.

The longer the mosquito lives, the greater will be the chances to bites multiple hosts and transmit diseases at higher rate. Thus, the lifespan of a mosquito, greatly affects the transmission of diseases.

Thus public health programs are focused on reducing the lifespan of mosquitoes to reduce their lifespan.

Frequently Asked Questions (FAQs)