Understanding the different stages of the mosquitoes life cycle can help prevent and effectively eliminate populations before they become a problem. All mosquito species have four distinct stages to their life cycle. Egg, Larvae, Pupa, and Adult. There are over 300 species of mosquitoes in the world. The most common and most dangerous, are the Culex mosquitoes. The Culex pipiens is the main carrier of the West Nile virus.