Mosquito life cycle

The female Anopheles mosquito life cycles has four stages: egg, larva, pupa, and adult.

• The first three stages (egg, larva, and pupa) are aquatic (live in water) and generally last 5–14 days to become adult in tropical conditions. Adult stage lives on land and can survive up to one month though generally lives for 1–2 weeks.
• A mosquito egg, larva, or pupa do not have malaria parasites inside it. Adult female mosquitoes may have malaria parasites in their bodies, but only if they have bitten someone who has malaria.

Diagram showing the life cycles of a mosquito

Eggs:

• Females must take a blood meal every 2–3 days. Blood is needed to develop eggs. Females will lay a batch of eggs before taking the next blood meal.
• Eggs are laid singly onto stagnant or slow-flowing water in batches of 50–200 eggs.
• Eggs are characterised by their lateral floats and attach by surface tension to the water surface or to objects in the water.
• If eggs dry out the mosquito will not develop.
• The length of time the egg takes to hatch into a larva depends on the temperature; typically, they hatch within 2–3 days. However, in colder regions it may take 2–3 weeks.

Larvae:

• Larvae have a head with mouth brushes for feeding.
• They position themselves parallel to the water surface to breathe via spiracles on their abdomen.

Pupae:

• When viewed from the side, pupae are shaped like a comma. Pupae must come to the water surface frequently to breathe.

• Pupae are very active and dive below the water surface at the slightest disturbance of the water.

• The pupae stage lasts from a few hours to a few days, after which the adult mosquito emerges.

Adult:

• Adult Anopheles mosquitoes have three body sections: the head, thorax, and abdomen. Attached to the thorax are three pairs of legs and one pair of wings.
• Anopheles mosquitoes can be distinguished from other mosquitoes by resting position, with their abdomens (rear ends) pointing upwards rather than held parallel to the ground.