Mosquitoes 101

The World's Most Deadly Animal

The life cycle of mosquitoes occurs in four stages. In the early stages, mosquitoes are aquatic organisms. Most female mosquitoes deposit their eggs on the surface of the water, either singly or in rafts (many eggs stuck together). (Some mosquitoes, such as Aedes aegypti, lay eggs on a dry surface next to a water source, so the next rain or flood can wash the eggs into the water to initiate development.) Mosquito development begins when the egg hatches and releases a larva. As the larva grows, it molts several times. Each of the stages between molts is called an instar. The fourth and last instar is the largest and is therefore the best specimen to use for identifying a larva. The fourth instar larva then develops into a pupa, which is the form it takes as it metamorphoses into an adult. The adult emerges from the pupal case on the surface of the water. The length of time it takes a mosquito to develop from egg to adult varies with species and is dependent on environmental conditions, such as temperature, moisture and nutrients.

 

 

Mosquito Life Cycle, Center for Disease Control

Know your Mosquito!

Major body parts of the mosquito larva are easy to see using an inexpensive clip-on magnifier for your smart device.


Close up of the terminal abdominal segments, important for identification of your larva:


Mosquito Larvae Comparison

Differences between larvae in the genera Anopheles, Aedes and Culex can be seen in resting positions shown below. Anopheles rests parallel to the surface because it breathes from spicules located on the thorax. Aedes and Culex rest at an angle to the surface, suspended from the surface of the water by their siphon. They breathe through the siphon.

 

Protocols for the GLOBE Mission Mosquito

GLOBE scientists have identified the GLOBE protocols that can help us understand the relationship between regional environmental conditions and changes in mosquito populations over time, including the first and last appearance of mosquitoes in regions where there is a defined mosquito season.


For investigations of aquatic mosquito ecology, all of the Hydrosphere protocols can be employed. Studies of water pH, water temperature, nitrates (nutrients), dissolved oxygen, water transparency, salinity, and water temperature can provide information about how these variables impact the rate of mosquito development. From the GLOBE protocol for Atmosphere, air temperature, precipitation, and relative humidity would be contributors in breeding season as would the GLOBE protocol in Pedosphere, soil moisture and soil temperature. Biosphere, land cover classification and green up-green down.

The links below will take you to the e-Training modules. The topics in parenthesis will enhance your understanding of the environmental factors affecting mosquito breeding habitats.