Floodwater mosquitoes
Floodwater species develop in early spring in woodland snowmelt pools and during the summer in woodland and open field rainwater pools or drainage ditches that hold water for a few weeks to months.
A number of floodwater breeding species occur throughout the US and can cause serious annoyance around dusk. Some of the more common species are: the common floodwater mosquito (Aedes vexans), the woodland pool mosquito (Aedes canadensis), the striped floodwater mosquito (Aedes trivattatus), the dark rice-field mosquito (Psorophora columbiae), the common white footed mosquito (Psorophora ferox), the gallinipper (Psorophora ciliata), the common malaria mosquito (Anopheles quadrimaculatus), the southern house mosquito (Culex quinquefasciatus), the unbanded saltmarsh mosquito (Culex salinarius), the winter marsh mosquito (Culiseta inornata) and other species that do not have common names (Aedes atlanticus, Aedes infirmatus, or Psorophora ferox).
But adaptation to biotopes that are dry most of the time and are only flooded irregularly results in very similar ways of life. Contrary to house mosquitoes, floodwater mosquitoes lay their eggs individually and normally deposit them on moist ground (a female can produce around 100 eggs after each bloodmeal). However, the larvae in the developing stage don’t hatch yet. Instead, they can survive in the embryonic membrane for up to three years.
But the larvae do not always hatch from the eggs, even if they manage to get into water. For example, low temperatures and an excessively high oxygen concentration in the water may prevent them from hatching. Important reasons: When it is cold, the development into a mature adult takes too long, the larvae would not survive in the wrong season and there are often fish and other natural enemies lurking in oxygen-rich waters.
When the circumstances are appropriate, for example, when rainfall pushes the ground water upwards and lets nutrient-rich puddles, small ponds and flooded meadows and fields in the spring and summer, larvae can hatch in masses almost simultaneously. If the temperature is right, the development into a mature adult only takes less than a week. In contrast to house mosquitoes, the female flood mosquitoes normally die no later than the onset of winter.