Life cycle of a mosquito Lesson 5 Unit: Diseases Mrs. Kalicharan

What does this picture show?

Adult mosquitoes Adult mosquitoes lay their eggs on the surface of stagnant water. Aedes aegypti which carries yellow fever, dengue and chikungunya prefers clean water.

Eggs - Larvae Within a few days the eggs hatch into active larvae (wrigglers). These fed on microscopic organisms in the water. The larvae breathe using air tubes which obtain atmospheric oxygen. Their gills extract oxygen that is dissolved in the water.

Larvae- Pupae They feed and grow for about a week or two and then change into pupae. Pupae hangs from the surface of the water and breathe in air. Inside the pupal case larval tissue are reorganised to form adult organs. After a few days a young adult emerges.

Adult female mosquito The mature female requires a meal of blood for her eggs to mature. When she bites a human she secretes saliva which prevents blood from clotting. If she bites an infected person she takes in pathogen in the blood.

Adult mosquito The pathogen goes through a stage of its life cycle and enters the salivary glands of the mosquito. When an infected mosquito bites a healthy person, saliva containing pathogens is injected into the person’s blood.

Life cycle of a mosquito

The four stages of a mosquito

Where each stage is found

Life cycle of a mosquito

Actual pictures of mosquito lifecycle

Exercise Draw and label each stage in the life cycle of a mosquito. Follow the rules of biological drawings. Include annotations indicating the habitat of each stage of the mosquito life cycle. Lab report (practice SBA)- 10 marks.