Mosquitoes are a diverse group, with over 2500 species in the world. In North America alone, there are 150 different species of mosquitoes. All mosquito species require being close to a water source. Additionally, part of the mosquito life cycle is always aquatic during early development and moves to terrestrial during adulthood.
Mosquitoes typically lay their eggs in the water. There are a few species that lay their eggs right above the water line, so when predictable flooding occurs, their eggs will hatch. The type of water the eggs are laid in varies and can include small containers, water filled tree holes, swimming pools, marshes, and large bodies of water. Mosquito eggs have the ability to over winter and then hatch in the spring.
Depending on conditions, mosquito eggs usually hatch within 48 hours of contact with the water. Larvae is the second stage of the mosquito life cycle and within this life cycle, they undergo four separate molts becoming more developed each time. Most species have a siphon tube that goes to the surface for breathing purposes, but there are a few species that lay parallel to the water surface to breathe. Other species attach to plant material in the water to get their oxygen supply. The larvae feed on microorganisms in the water as they continue to develop. Depending on water temperature and species this part of the mosquito life cycle occurs anywhere from days to weeks.
After the larvae undergo the fourth molt, it enters into a casing stage called pupae. The pupae stage also occurs in the water, but unlike many insects it is still a very active stage. No feeding occurs at this stage, but the pupa is light sensitive and will dive to the bottom when it senses predators. It typically floats at the surface to breathe. This part of the mosquito life cycle takes anywhere from one to four days.
Using air pressure, the now adult mosquito breaks from the hard casing and emerges. It rests until its wings dry and body hardens and then immediately flies away searching for a mate and food. Males generally live only a few days after mating, but female mosquitoes can live up to a month. How fast the mosquito life cycle repeats is dependent on temperature and humidity.