The life cycle of mosquitoes consists of four stages: the egg, the larval stages (larva), the pupa and, finally, the adult. Apart from the last stage, the adult (the well-known annoying mosquito that bites us), all the others are aquatic.
The duration of the life cycle of mosquitoes mainly depends on temperature. The lifespan of adult mosquitoes usually depends on several factors including temperature, humidity, the sex of mosquitoes and the season of the year. Males live about a week, whereas females usually live longer, but their lifespan can be up to one month. Apart the nuisance that they cause, mosquitoes are also vectors of several human diseases, such as malaria, Dengue hemorrhagic fever, yellow fever, Chikungunya and West Nile Virus.
- The egg
- Female mosquitoes spot a suitable aquatic breeding site to lay their eggs. The incubation period (the time period between laying and hatching of the eggs) may vary considerably among mosquito species. The eggs laid on the water surface hatch in 1-3 days, but this time period depends on temperature. Some species lay their eggs on damp soil or other substrate (e.g. tree trunks) but the incubation period varies since the eggs hatch as soon as they are covered with water (rainwater, melted snow or when similar environmental conditions occur). Female mosquitoes lay 100 to 500 eggs (300 on average) during each gonotrophic cycle, but these numbers depends on mosquito species. In the following ovipositions, which can be up to 10, female mosquitoes lay fewer eggs.
- The larva
- Egg hatching gives birth to the 1st instar larvae. These tiny larvae feed on microorganisms and other organic particles in water and increase in body size. The larval stage is a feeding one and larvae move fast with that typical turn of the abdomen. Mosquito larvae pass through four instars (1st, 2nd, 3rd and the 4th) and each instar in a row is bigger than the previous one. The larval stage usually lasts for 7-10 days, but its duration depends on mosquito species and water temperature. The duration of the larval stage can be as short as 5-7 days, when there is plenty of food and temperatures are suitable. At the end of the 4th instar, larvae pass to the pupal stage after having separated their cuticle.
- The pupa
- Mosquito pupae are comma-shaped. Unlike most insects, the pupae of mosquitoes are aquatic and very mobile. However, mosquito pupae differ significantly from larvae in shape and form. The front part of those pupae is quite large and consists of the head and thorax (cephalothorax). This part also includes a pair of respiratory components (respiratory trumpets), resulting in longer stay on the water surface. As pupae mosquitoes do not feed and the duration of this stage is short (usually 3 days or less).
- The adult
This is the final biological stage of mosquitoes. The adult (the well-known mosquito that everyone knows) begins to breathe air when is fully formed. This results in increasing the internal pressure and eventually the adult emerges standing on the water surface. The nutritional requirements of adult mosquitoes are not the same between the male and the female. The mouthparts of male mosquitoes are not fully developed and are only suitable for sucking nectar, whereas the mouthparts of female mosquitoes are strong and suitable for skin piercing and sucking blood.
The biting mosquito…
Like all insects, mosquitoes need energy for their activities (flying, mating, etc.), which they receive from nectar, the secretions of insects (e.g. aphids) and mature fruits. Only female mosquitoes seek blood to suck in order to build their eggs.
And the life cycle continues over again….